72 Convertible 442 Clone
#1
![Smile](https://classicoldsmobile.com/forums/images/icons/icon7.gif)
OK guys I`m a Newbie to the Olds world and this will be my first project. I have always wanted a convertible. I am starting with a pretty clean Cutlass Body that I hope to have finished by June. Disassembly started this week and I was pleasently surprised with the conditionas I starting taking this thing apart. Also impressed with Olds Build quality. This is not a 100 pt show car but a nice driver. Please feel free to jump in with suggestions. I do not know a lot about origional finish so i am depending a lot on the reference material on this site........OK here is what we are starting with. Pretty good body with rust in the lower doors and some on the lower trunk lid.
#2
welcome, looks like you have a great car to start with. as far as info and help with your restoration you are at the right place whether it be a 100% concours resto to a garage make over. these guys love to help. they have been invaluble {sp} in info on my restoration. good luck with your build!!
charlie,,,
charlie,,,
#3
That car looks to be very solid! Good luck with your resto. Lots and Lots of helpful folks on here for your upcoming questions. Pulling and re installing the dash can be a real pain in the butt. I'm glad I only had to do mine 1 time.
#4
Welcome to CO.
Wow - that is an excellent "core" car to start with.The interior looks excellent and not butchered/monkeyed with. It seems so nice to me it might worth be doing an authentic resto to exact original configuration - especially if it was originally red.
Wow - that is an excellent "core" car to start with.The interior looks excellent and not butchered/monkeyed with. It seems so nice to me it might worth be doing an authentic resto to exact original configuration - especially if it was originally red.
#5
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Welcome to C.O.
Why do you want to clone that car? It looks like you could easily take it to a complete restoration without a lot of work.
Check your cowl tag. If the PNT code is 75 (Matador Red) it's the color it came from the factory with. If the letter beside the PNT is A - white top, B - Black top.
Got any pics of the cowl tag? Your VIN should start out 3J67K2 The next letter will be the factory, then the last 6 will be the production sequence of the car (will not match the cowl tag).
Why do you want to clone that car? It looks like you could easily take it to a complete restoration without a lot of work.
Check your cowl tag. If the PNT code is 75 (Matador Red) it's the color it came from the factory with. If the letter beside the PNT is A - white top, B - Black top.
Got any pics of the cowl tag? Your VIN should start out 3J67K2 The next letter will be the factory, then the last 6 will be the production sequence of the car (will not match the cowl tag).
#6
Thanks for the welcome and support guys. This car was origionally Saturn Gold with a Black top and black bench seat interior. Also correct about the dash being a pain. I ordered a Cutass assembly manual this morning. I cannot figure out what is holding the dang thing to the car! HaHa. The floors of this thing are coated in undercoating. Top and bottom. It has done an excellent job of protecting them as wherever I remove some I get to origional color or shiny bright metal. Any thoughts on just leaving this alone since it seems to have done such a good job. I realise this is not factory correct but again this is a driver and I want to protect it for as long as I can.
#7
Well, you've come to the right site! In the extremely short time I've been a member I have learned a great deal about my car and I have been helped with finding parts that I thought would take much longer to locate. This site is a blessing to the Oldsmobile enthusiast.
Great looking Cutlass! It should be an excellent start for your build! I can't wait to see more pictures.
Great looking Cutlass! It should be an excellent start for your build! I can't wait to see more pictures.
#8
Thanks for the welcome and support guys. This car was origionally Saturn Gold with a Black top and black bench seat interior. Also correct about the dash being a pain. I ordered a Cutass assembly manual this morning. I cannot figure out what is holding the dang thing to the car! HaHa. The floors of this thing are coated in undercoating. Top and bottom. It has done an excellent job of protecting them as wherever I remove some I get to origional color or shiny bright metal. Any thoughts on just leaving this alone since it seems to have done such a good job. I realise this is not factory correct but again this is a driver and I want to protect it for as long as I can.
A tip after disconnecting everything, you don't need to pull the harness out before pulling the dash. Leave it attached to the dash - the assy manual will show you what to disconnect like dimmer switch, ignition switch leads, door jamb switches, speedometer, etc....
If it's going to be a driver, I'd leave those floors alone.
#9
Thanks for the welcome and support guys. This car was origionally Saturn Gold with a Black top and black bench seat interior. Also correct about the dash being a pain. I ordered a Cutass assembly manual this morning. I cannot figure out what is holding the dang thing to the car! HaHa. The floors of this thing are coated in undercoating. Top and bottom. It has done an excellent job of protecting them as wherever I remove some I get to origional color or shiny bright metal. Any thoughts on just leaving this alone since it seems to have done such a good job. I realise this is not factory correct but again this is a driver and I want to protect it for as long as I can.
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#10
Resto topics
Got the car torn down to just about the bare bones. Taking my time tagging and bagging. Hope I can remember where everything goes when it comes time to start assembling. Hope to send body off to paint next week. I ordered a bunch of parts yesterday. Sure is hard to fight that MAW and keep this thing on budget. Ii did decide to go ahead and install discs and a new front suspension now. Everything is just so easy to get to at this point so MAW! Do you guys have any suggestions for preserving finishes on natural steel parts such as nuts and bolts or even backing plates for the disc brakes that were not painted from the factory? I was wondering about how clear coating some of these items would work?
#11
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Satin clear works well on parts that won't be on high heat areas. If it's in a high heat area, I found NAPA 'cast' works great and give an almost natural metal color.
#12
Thanks Allan will try the clear on the bare steel stuff. Assembly manual has been ordered and on the way and have about 100 pics so far. Let the fun begin. I am a little confused on my engine #`s. It has # 6 heads which I thought were 1970. and the casting # on the front top of the block (by oil filler spout) are 395558. According to the tech section this would be a 1973. Doesn`t look like this is the origional stuff..........any thoughts
#13
Here are some pics of where I am. I have the body mounts coming along with a disc brake conversion kit. Still trying to decide on a front end kit. Just about everthing that is external to the engine is on order. Will start detailing engine comp and engine tomorrow. Spoiler is on the way from TPP along with the dual gate and rally pack. Still undecided on whether to go with a OAI Hood. I have the louvered hood now. I have seen a lot of posts with people having fitment and quality issues with most of these hoods. I found some rust on the bottom of the radiator core support in the area of the mount. This is under the battery tray and acid probably contributed. Does anyone know if you can buy the bottom section for this to weld in..... Also any suggestions for cleaning the wiring harness? It has overspray and is dirty but seems to be in good shape otherwise.
#14
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
I am a little confused on my engine #`s. It has # 6 heads which I thought were 1970. and the casting # on the front top of the block (by oil filler spout) are 395558. According to the tech section this would be a 1973. Doesn`t look like this is the origional stuff..........any thoughts
The 395558 is a SBO, but you need to look for the big number just to the right side of that. If you have 36955582 that's what it was from 68-74. If you have a 5 that would be the last batch of 350's from 74-76.
The #6 heads do not have hardened valve seats like the 71/72 models did in anticipation of unleaded fuel. Easy enough fix if you want the right heads. There are guys on the site who part out the cars and have plenty of them.
You're in NC, so I'd say touch base with:
Scott Winn (oldspackrat)
Eric Jensen (jensenracing77)
Both of those guys are in Indiana. Scott is Indianapolis, Eric is Brazil.
You've got lots done so far. Before you forget, use your compressed air and blow out the leaves and crud that's accumulated in the back of the fender to cowl area. Any moisture in there will be acidic with those leaves getting damp or wet. Working on the front end will be a snap with the engine and rad support out of the way.
At this stage of the game, you might as well take out all the steering related parts and detail the front frame.
re: cleaning the wiring harness. I've used oven cleaner to do the trick and it worked well. Needed a couple tries though. When you're done, make sure you rinse the spade connectors well, use compressed air to dry and then shoot them with Electrical Contact Cleaner (not TB or carb cleaner). Should come out like new.
Here's my gas tank sender wire before and after using that technique (and it was nasty)
#15
Looking at your latest set of pictures, I would really consider doing a resto back to original condition. Looks like your car hasn't been abused and hacked up. Keep us all posted!
Take your time on the harnesses. Get a nice big table to work on, and just start at one end and clean/repair/renew every wire following it fom one end to another. If any harnesses are too far gone, consider getting nice used ones before getting the repos. I got some excellent ones off eBay for less than half the repos and they are obviously going to be exactly correct
Take your time on the harnesses. Get a nice big table to work on, and just start at one end and clean/repair/renew every wire following it fom one end to another. If any harnesses are too far gone, consider getting nice used ones before getting the repos. I got some excellent ones off eBay for less than half the repos and they are obviously going to be exactly correct
#16
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Joe, that's exactly what I did too. I have around 5 harnesses I can pick and choose connectors from for any rebuild I need to do, plus the sleeves they fit in.
#17
Authenticate Engine
Sampson:
Welcome to CO. Here some info help with IDing the engine. There is a machined pad on the block by the No1 cylinder that has a VIN derivative stamping. You can use this to authenticate the engine to the car. For '72 it should read 32Mxxxxxx
3-Olds division
2-production year
M-plant location M=Lansing, B=Baltimore, X=Kansas City, Z=Freemont, CA
xxxxxx-should match the last 6 digits of the VIN number.
The filler tube has a stamping as well and the first digit denotes the year of the block. So it should start with a 2 for 1972. Of course the filler tube could have been changed but it's a quick way to check the year of the block. Good luck with your project.
Welcome to CO. Here some info help with IDing the engine. There is a machined pad on the block by the No1 cylinder that has a VIN derivative stamping. You can use this to authenticate the engine to the car. For '72 it should read 32Mxxxxxx
3-Olds division
2-production year
M-plant location M=Lansing, B=Baltimore, X=Kansas City, Z=Freemont, CA
xxxxxx-should match the last 6 digits of the VIN number.
The filler tube has a stamping as well and the first digit denotes the year of the block. So it should start with a 2 for 1972. Of course the filler tube could have been changed but it's a quick way to check the year of the block. Good luck with your project.
#18
Suspension paint questions
Well I am almost through scraping undercoating and cleaning grease from the front frame and suspension. Now comes the detailing. I plan to paint the frame w/Por15 semi gloss. Wondering what the finish was on some of the other suspension items like the sway bar, sway bar mounts, springs, steering components like tie rod ends and the tie rod couplers. Also the bolts for everything are they natural? Keep in mind this will be a driver so doing it the way the factory did it is not a priority. But I would like it to appear close to factory. If it was origionaly left bare steel I will paint it to look like steel...also wonder about shooting bolts with clear after installed to keep them looking natural. Any thoughts or suggestions before I start detailing?
#19
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
If it's a driver - just go with a semi gloss or gloss black on all the parts and it will come out looking great. Only time you need to be nit picky is if this was a concourse resto which it's not. Anything you want to look natural? Shoot it with semi gloss clear before you install it. On all your theads, use a bit of anti seize - makes assembly really easy and prevents corrosion on bolts/nuts if you have to take anything apart.
My suggestion FWIW, would be to do most everything black, but be creative with some of the parts you want to have contrast so they pop out on a looksee instead of fading into the background.
Front suspension parts? You'll get a lot of opinions. I did my front steering parts including the front sway bar in 'cast' which simulates natural metal really nicely. If you want to see how they turned out take a look at the album on my home page; it has 43 pics of what I think you're asking about https://classicoldsmobile.com/forums...+r-albums.html
My suggestion FWIW, would be to do most everything black, but be creative with some of the parts you want to have contrast so they pop out on a looksee instead of fading into the background.
Front suspension parts? You'll get a lot of opinions. I did my front steering parts including the front sway bar in 'cast' which simulates natural metal really nicely. If you want to see how they turned out take a look at the album on my home page; it has 43 pics of what I think you're asking about https://classicoldsmobile.com/forums...+r-albums.html
#20
#21
Allen. Thanks for the advise and the thread to your front end rebuild. This was exactly what I was looking for. The pics are great and you have done exactly what I have in mind. I also understand what you went through with the undercoating. It is 1/4 " thick on everything on my car. Not overspray but coated. This stuff is unbelievable to get rid of. I probably have 24 hour in cleaning just the front horns of my frame alone. After about 4 hours on one of the upper control arms this week I decided to send them off for blasting and powder coating.
#22
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
You're welcome Sampson. If you run into questions about what I did on that thread send me a PM and I'll do my best to help. There are some things I'd do different. In fact I'm probably going to revisit that front end in the spring and make a few changes for the better. Yeah, undercoating is a beach isn't it? We should form an undercoating grunt club...ar ar ar ar ar ar...pass me that Binford 2328 heat contact tar chisel would ya??? ![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
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#23
Finally some progress to report!
Ok Guys I finally have gotten past the gunk and scraping and getting around to putting some stuff back on the car. Progress has been a little slower than planned. Had to work around the weather. Ideal painting conditions are few and far between in Jan. I`ve had too much pain and suffering in the past trying to paint when the humidity is too high or temp too low too rush this stage.
Here are a couple of before during and after shots of the frame. Took front frame down to bare metal...lots of hours here. Used POR Marine Clean and Metal Prep before 2 coats of POR 15 semi gloss black. The pic of the frame with the white residue is how the frame looked after coating with Metal Prep. I really liked the POR for the base. Goes on great and gives a really hard protective coat. I was not 100 % satisfied with the final finish with the POR 15 so I followed up with their etching primer followed by 2 coats of Eastwood`s Extreame Chassis Black. Took a little more time but I was really happy with the result.
![Wink](https://classicoldsmobile.com/forums/images/smilies/wink.gif)
#24
Suspension Parts Restoration
I sent the control arms and springs out to be blasted and powder coated. Used all Moog replacement parts for the steering components. Parts that wer reused were stripped, wire wheeled and primed, then final coated with Eastwood Spray Gray on cast parts. Bare steel Items like Ball joint tops, nuts, etc were given 3 coats of clear. I use a heavy paper towel in my sockets when reinstalling finished nuts and bolts to protect the new finish. Steering box is the Jeep Grand Cherokee conversion with a LARS 202 Rag joint. Box bolts right in and looks identical to origional. Still need to order the fitting adapters from Lee engineering. Note these pics were taken before all bolts are torqued and cotter pins installed etc. I bought stainless cotter pins from the local big box to use as replacements. Spindles are part of the disc brake conversion kit from The Parts Place. I can`t wait to get the rest of the brake kit detailed and installed. Biggest PITA on this part of the job was getting the springs compressed and installed. I could not get the springs compressed enough to get the nuts started for both upper and lower control arms.
Took me a while to figure out that the spring compressor bolt was too long and preventing the CA from moving as far as it should
. Anyway a word of caution to anyone new to this. Do not attempt to remove or install the springs without the proper tool. I ve seen some pretty scary pics of back yard attempts to do this. The factory Assembly manual is also an invaluble tool here as all the torques and footnotes are there. Plus it is all pics.
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#25
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Sampson,
I agree working with springs is dangerous because of the energy they store. But putting them back in shouldn't have needed a spring compressor. Just have to drop the lower control arm right down. Insert upper spring into the frame pocket. Use a 3' line bar to wedge the bottom over the lip of the lower control arm. Put dolley jack under lower control arm and jack the CA up to the point where the ball joints will connect to the spindle. Taking the springs out was just as easy and not dangerous at all if done right.
I hope you haven't torqued the control arms yet. That needs to be done when the car has weight on it.
Overall the look of the project is coming along very nicely. Congrats on the fine job you're doing.
I agree working with springs is dangerous because of the energy they store. But putting them back in shouldn't have needed a spring compressor. Just have to drop the lower control arm right down. Insert upper spring into the frame pocket. Use a 3' line bar to wedge the bottom over the lip of the lower control arm. Put dolley jack under lower control arm and jack the CA up to the point where the ball joints will connect to the spindle. Taking the springs out was just as easy and not dangerous at all if done right.
I hope you haven't torqued the control arms yet. That needs to be done when the car has weight on it.
Overall the look of the project is coming along very nicely. Congrats on the fine job you're doing.
#26
I hear ya Allen and I have changed them that way as well but with the engine out there wasn't enough weight to keep the car down. Instead of compressing the spring the car went up. I tried to jury rig strapping the frame to the jack but it just was not safe.
#27
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Ah, now I gotcha! I saw a guy do the spring install on a Firebird using the tie down method on the jack and frame. Seemed like a lot of work and risk all things considered. I didn't think there was a large enough hole for the shock to let a spring compressor thread bolt down through there....
#29
Yea Allan just barely enough room to get the compressor through the shock hole but the real problem comes from the springs are compressed enough they clamp down on the jaws of the compressor. A real PITA to get the compressor back out of the spring. Maybe a different style compressor would have been better. Some of the McPherson strut types clamp on the outside of the spring. Maybe that would work better. Anybody else have a better method? Also I have not torqued the control arms yet. Wondering if I need to wait until I get the engine back in or is it enough to have the weight of the car on them?
#30
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Yea Allan just barely enough room to get the compressor through the shock hole but the real problem comes from the springs are compressed enough they clamp down on the jaws of the compressor. A real PITA to get the compressor back out of the spring. Maybe a different style compressor would have been better. Some of the McPherson strut types clamp on the outside of the spring. Maybe that would work better. Anybody else have a better method? Also I have not torqued the control arms yet. Wondering if I need to wait until I get the engine back in or is it enough to have the weight of the car on them?
re: bushing torque? Wait for the engine to get back in to torque the control arms. Otherwise you could end up over stressing those new bushings which would lead to them failing early. You need as close as possible to the FULL weight of the car on them for the best results.
#31
Redneck Body Lift
Thought I would bring you guys up to speed on the recent activity. Also decided to go ahead and get the frame out from under the car so I can detail it a little better. My body lift is a little crude but effective. Just gotta take it slow going up. As with any project like this there are ups and downs. My body guy was supposed to be able to take the car Jan 1rst. I kept going by his shop and didn`t see where he was making any progress with the work going on in there. Seems he had a new drama every week.
Also could not get him to get firm on a price. It was always it will be about xxxx.
Had heard about Dan @ NC Classic Restorations. He came to my house and spent 2 hours with me going over the car top to bottom. He had lots of questions about how I wanted to do this and that. He came back with a detailed estimate and explained exactly what was included in the price. It is a little more money but I can tell this is the right guy for the job. Went down to his shop and looked at some of the amazing work going on there. Anyway car will be going into his shop April 1rst. I have to get in gear. Meanwhile the engine is in the shop at Steve Ashworth Performance in Fuquay Varina. I told my wife it was being regasketed.
Originally I had only planned to freshen it up but when we decided it would need a bore why not go ahead with a little more compression. And since I was going to give it a valve job anyway why not make it a competition with a little bowl blending?
Well it comes down to I have about 4 weeks to get the engine back together and in the car and the frame finish detailed so I can get the car back on the body to take to to the shop for paint
Life is good!
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#32
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Lessee, how good was your math at school??? ![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
Ok, seriously.
You have to be doing something wrong. Let's say you have a 3.23 or 3.42 gearset. If you turn the wheel one full revolution (start the index at 12 o'clock position for simplicity) the drive shaft will rotate 3.23 or 3.42 times. But gauging 3.23 or 3.42 is really hard sometimes.
That's why you turn the wheel 10X. That will force the driveshaft to rotate 32.3 or 34.2 times. Even if you count it as 32 or 34 and divide by 10? You get 3.2 and 3.4 which will be close to the actual gear.
This can also be a PITA if your gears are 2.56, 2.73 or 2.93. They are numerically close together but the driveshaft would turn 25, 27 or 29 times which would take away all the guess work.
Only thing I can think of that would come even close to your number is if you rotated the tire 5 times and still divided the driveshaft by 10. That would change a 2.56 gear number to look like 1.25:1
Ok, here's something else to do. You have your body off the frame. You axle is exposed which will give you the chance to find the axle code. See where the vent tube is on the passenger side? Right beside that is where the axle code stamping is. Use fine sandpaper to sand away the crud, but the code should be there. I'm betting you have a 2.73:1 axle, which was standard for the 72 CS. The code might start out like this SA OXXX. SA means 2.73, O = Oldsmobile and the last 3 numbers are the oridinal date of 1972 that the axle was assembled. This assumes standard production and no one having changed your differential gears during the car's life.
What is the build month/week of your car? I'm really wondering if it might have been built with leftover production from 1971 when the CS had a 2.56:1 rear axle standard. Someone might have even special ordered it that way if they were using the car as a highway cruiser (like in NV or NM).
![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
Ok, seriously.
You have to be doing something wrong. Let's say you have a 3.23 or 3.42 gearset. If you turn the wheel one full revolution (start the index at 12 o'clock position for simplicity) the drive shaft will rotate 3.23 or 3.42 times. But gauging 3.23 or 3.42 is really hard sometimes.
That's why you turn the wheel 10X. That will force the driveshaft to rotate 32.3 or 34.2 times. Even if you count it as 32 or 34 and divide by 10? You get 3.2 and 3.4 which will be close to the actual gear.
This can also be a PITA if your gears are 2.56, 2.73 or 2.93. They are numerically close together but the driveshaft would turn 25, 27 or 29 times which would take away all the guess work.
Only thing I can think of that would come even close to your number is if you rotated the tire 5 times and still divided the driveshaft by 10. That would change a 2.56 gear number to look like 1.25:1
Ok, here's something else to do. You have your body off the frame. You axle is exposed which will give you the chance to find the axle code. See where the vent tube is on the passenger side? Right beside that is where the axle code stamping is. Use fine sandpaper to sand away the crud, but the code should be there. I'm betting you have a 2.73:1 axle, which was standard for the 72 CS. The code might start out like this SA OXXX. SA means 2.73, O = Oldsmobile and the last 3 numbers are the oridinal date of 1972 that the axle was assembled. This assumes standard production and no one having changed your differential gears during the car's life.
What is the build month/week of your car? I'm really wondering if it might have been built with leftover production from 1971 when the CS had a 2.56:1 rear axle standard. Someone might have even special ordered it that way if they were using the car as a highway cruiser (like in NV or NM).
#33
Lessee, how good was your math at school??? ![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
Ok, seriously.
You have to be doing something wrong. Let's say you have a 3.23 or 3.42 gearset. If you turn the wheel one full revolution (start the index at 12 o'clock position for simplicity) the drive shaft will rotate 3.23 or 3.42 times. But gauging 3.23 or 3.42 is really hard sometimes.
That's why you turn the wheel 10X. That will force the driveshaft to rotate 32.3 or 34.2 times. Even if you count it as 32 or 34 and divide by 10? You get 3.2 and 3.4 which will be close to the actual gear.
This can also be a PITA if your gears are 2.56, 2.73 or 2.93. They are numerically close together but the driveshaft would turn 25, 27 or 29 times which would take away all the guess work.
Only thing I can think of that would come even close to your number is if you rotated the tire 5 times and still divided the driveshaft by 10. That would change a 2.56 gear number to look like 1.25:1
Ok, here's something else to do. You have your body off the frame. You axle is exposed which will give you the chance to find the axle code. See where the vent tube is on the passenger side? Right beside that is where the axle code stamping is. Use fine sandpaper to sand away the crud, but the code should be there. I'm betting you have a 2.73:1 axle, which was standard for the 72 CS. The code might start out like this SA OXXX. SA means 2.73, O = Oldsmobile and the last 3 numbers are the oridinal date of 1972 that the axle was assembled. This assumes standard production and no one having changed your differential gears during the car's life.
What is the build month/week of your car? I'm really wondering if it might have been built with leftover production from 1971 when the CS had a 2.56:1 rear axle standard. Someone might have even special ordered it that way if they were using the car as a highway cruiser (like in NV or NM).
![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
Ok, seriously.
You have to be doing something wrong. Let's say you have a 3.23 or 3.42 gearset. If you turn the wheel one full revolution (start the index at 12 o'clock position for simplicity) the drive shaft will rotate 3.23 or 3.42 times. But gauging 3.23 or 3.42 is really hard sometimes.
That's why you turn the wheel 10X. That will force the driveshaft to rotate 32.3 or 34.2 times. Even if you count it as 32 or 34 and divide by 10? You get 3.2 and 3.4 which will be close to the actual gear.
This can also be a PITA if your gears are 2.56, 2.73 or 2.93. They are numerically close together but the driveshaft would turn 25, 27 or 29 times which would take away all the guess work.
Only thing I can think of that would come even close to your number is if you rotated the tire 5 times and still divided the driveshaft by 10. That would change a 2.56 gear number to look like 1.25:1
Ok, here's something else to do. You have your body off the frame. You axle is exposed which will give you the chance to find the axle code. See where the vent tube is on the passenger side? Right beside that is where the axle code stamping is. Use fine sandpaper to sand away the crud, but the code should be there. I'm betting you have a 2.73:1 axle, which was standard for the 72 CS. The code might start out like this SA OXXX. SA means 2.73, O = Oldsmobile and the last 3 numbers are the oridinal date of 1972 that the axle was assembled. This assumes standard production and no one having changed your differential gears during the car's life.
What is the build month/week of your car? I'm really wondering if it might have been built with leftover production from 1971 when the CS had a 2.56:1 rear axle standard. Someone might have even special ordered it that way if they were using the car as a highway cruiser (like in NV or NM).
Last edited by Sampson; March 27th, 2013 at 05:46 PM.
#34
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Well, according to your pic of the axle code it's NOT an Olds manufactured axle. It's from a Buick. (likely Skylark) I know that for an Olds differential the SA code means 2.73 open. If in fact Olds put Buick axles into Cutlass modes and stamped the gearing codes for Olds I don't know. The second number 253 would be the day it was built. Using an ordinal calendar that would be around Sept 10, 1972 I don't know how Buick coding really works. The 2 at the end could mean 72 model production??
I know that my axle was coded SA O 101 which is an Olds 2.73 open and 101 was the exact ordinal date my car was assembled and shipped from Lansing. I have the broadcast sheet and GM documentation to prove it.
The 'blue glue' you're talking about is RTV sealant. All that means is someone opened the cover; likely to change diff fluid. Instead of using a gasket they used RTV Blue instead. No big deal, it's a common gasket maker.
Count the number of teeth on the ring gear. If it's got 41 and 15 on the pinion you do have a 2.73
I know that my axle was coded SA O 101 which is an Olds 2.73 open and 101 was the exact ordinal date my car was assembled and shipped from Lansing. I have the broadcast sheet and GM documentation to prove it.
The 'blue glue' you're talking about is RTV sealant. All that means is someone opened the cover; likely to change diff fluid. Instead of using a gasket they used RTV Blue instead. No big deal, it's a common gasket maker.
Count the number of teeth on the ring gear. If it's got 41 and 15 on the pinion you do have a 2.73
#35
Well, according to your pic of the axle code it's NOT an Olds manufactured axle. It's from a Buick. (likely Skylark) I know that for an Olds differential the SA code means 2.73 open. If in fact Olds put Buick axles into Cutlass modes and stamped the gearing codes for Olds I don't know. The second number 253 would be the day it was built. Using an ordinal calendar that would be around Sept 10, 1972 I don't know how Buick coding really works. The 2 at the end could mean 72 model production??
I know that my axle was coded SA O 101 which is an Olds 2.73 open and 101 was the exact ordinal date my car was assembled and shipped from Lansing. I have the broadcast sheet and GM documentation to prove it.
The 'blue glue' you're talking about is RTV sealant. All that means is someone opened the cover; likely to change diff fluid. Instead of using a gasket they used RTV Blue instead. No big deal, it's a common gasket maker.
Count the number of teeth on the ring gear. If it's got 41 and 15 on the pinion you do have a 2.73
I know that my axle was coded SA O 101 which is an Olds 2.73 open and 101 was the exact ordinal date my car was assembled and shipped from Lansing. I have the broadcast sheet and GM documentation to prove it.
The 'blue glue' you're talking about is RTV sealant. All that means is someone opened the cover; likely to change diff fluid. Instead of using a gasket they used RTV Blue instead. No big deal, it's a common gasket maker.
Count the number of teeth on the ring gear. If it's got 41 and 15 on the pinion you do have a 2.73
#36
Milestone event day
Today is a big day in the Cutlass referb project. The Chassis is complete and the body and chassis head off to the paint shop tomorrow. It has been a real hustle the last couple of weeks to get it ready to go. Here are a couple pics of the bare chassis today before I rolled it back under the body. I am pumped to get it to this phase. I will post some progress pics of the steps along the way in the next couple of days.
https://classicoldsmobile.com/forums...-chassis-8.jpg
https://classicoldsmobile.com/forums...-chassis-8.jpg
Last edited by Sampson; July 23rd, 2013 at 10:01 AM.
#38
![EEK!](https://classicoldsmobile.com/forums/images/smilies/eek.gif)
![Big Grin](https://classicoldsmobile.com/forums/images/smilies/biggrin.gif)
#39
#40
Surprise Surprise
I haven`t posted the progress on this project since completing the front suspension back in Feb. Originally this was going to be a frame on project with some detailing underneath. But every project has some surprises and this one was no different. First I ran into a stripped cage nut in the right rear body mount. I had the body jacked up off the frame to replace the body mounts and noticed a strange looking welded plate on the frame. Almost looked factory with paint on it but not.
So I got out the grinder and started investigating This is what was lurking under a plate welded to the frame.
![Confused](https://classicoldsmobile.com/forums/images/smilies/confused.gif)
![EEK!](https://classicoldsmobile.com/forums/images/smilies/eek.gif)