66-3X2 442

Again,I'm not trying to say I'm right & the others are wrong about anything. I'm just researching the possibility that that 70 A/C cars could have come with 3.42 rears. If it was just one car,I can see where it comes under scrutiny but when two or more 70 W-30 A/C cars have correct W-30 code TM rears,that's very strange. We may be getting close to the documentation on the possibility of it. Check this thread out,particularly the post by Dr Dan.

http://72.22.90.30/phpBB2/viewtopic....er=asc&start=0

anthonyP

It was odd that Buick allowed A/C on their GS455 with a 3.42 axle ratio, while Olds only allowed a 3.23. But then again, the GS455 had the 15" rims for a taller profile, and lower RPM's, unlike Oldsmobile. Did Pontiac offer a higher ratio than 3.23 with A/C on the GTO?

It was also odd how Olds supposedly did not allow A/C on a 442 with a 4-speed, since according to the brochures, the M-21 was not available with 3.23 gears - but the factory did build 4-speed 442's with A/C by substituting the M-20 trans, which was not suppose to be available in a 442.

No one knows why Oldsmobile did not offer 15" rims on the 70-72 442, when they had them on the '69 H/O - which would had allowed them to offer the wider 60 series tires, not unlike Buick in 1970, and Chevy & Pontiac in '71 & '72.

Boiler_81

Since this old thread got revived, did you ever get the date code?

66-3X2 442

I have since sold the car but I did get the date code and it was correct for the car. When all of this discussion was going on,another 70 W-30 A/C car was found with a TM code 3.42 rear axle.

stevengerard

I need to check the rear on the hardtop W30. According to the order form it came with AC and 3.23s but I am not sure what code is on the axle tube. I'll try to check it today. I have yet to check the date code on the convertible with the 3.42s/AC

BlackGold

With so many '70 W-30 A/C cars with 3.42 axles showing up, it should be easy to find one with factory documentation saying that's how it was built. Just sayin'.

I'll never say never. But I'll also never believe it's true until I see the documentation. It's WAY more likely the 3.42 rears were installed by the dealer or original owner shortly after purchase. Though frankly it seems odd to me that anyone would go to the trouble for just 6% lower gears.

66-3X2 442

Gears maybe but why the TM code? I don't care one way or the other if they came with 3.42 gears and A/C. I'm just relaying what I have seen and been told. It sure is funny that the 3.42 geared A/C cars I have known of or have been told have all been W-30 cars. Coincidence? Like I said,things changed for me when I realized anything is possible. So all of you guys who know for a fact there were no 70 3.42 A/C cars,so be it because I'm done with my observations. I am not trying to convince anyone,just relaying the info I have collected.

stevengerard

The axle code isn't on the broadcast card from what I remember is it? What about W27, would that show up. I seem to remember only W30, C60(sometimes) and U80 show's up on broadcast cards. I have to dig mine out - have no idea where they are at (YIKES)

pogo69

short of a pontiac 455 being installed in a cutlass ... most anything could of been possible back then any docs would be helpfull though

wmachine

I've gone over this again since this was brought up again. I do have some more observations.
1. Any documentation I have is up to the end of Feb, 1970. So it is possible that a change was made late in the year. Build dates of these "exception cars" would help allow or disallow this as a possibility.
2. If you look at the rear end usage pages from the '68-'70 Assembly Manuals, you'll see that Olds got more adamant about no 3.42s and lower with AC/HD Cooling as time went on. The '70 page even says specifically for the dealers to *not* install 3.42s and lower with AC/HD Cooling.
3. This is not a W30 thing. It was all about AC/HD cooling.
4. Since it was also about HD cooling, the reason has nothing to do with the AC compressor or components other than the HD cooling parts.
5. Most importantly, if 3.42s were *not* available, why are the 3.42s out there? 3.42 TM codes and all? The reason for that is that the 3.42s came with the HD axles, bearings, and carriers too. And you couldn't swap out just the gears. So the better swap was the whole rear.
My vote is still with no 3.42s from the factory. Of course documentation is always welcome.



Please don't start with the "anything was possible" suggestion. Simply not true.

pogo69

i will admit that i am using the ''anything was possible'' phrase only because i have heard that before so i guess i am a bandwagon jumper...i dont know how dealerships and detroit worked together back then but in my mind it seems it would of been easier then today ( everything on the computer) to make a call or put a ''special order'' in when buying a car maybe some sales people from back in the day could answer

Boiler_81

I agree, I have been in auto assembly plants throughout the the world over the last 30 years. Exceptions to the build are huge disruption to the process. I would have to see paperwork showing the 3.42 was released to production in order to be convinced.

Ironically, I would believe a one off (with documentation) as an exception. I was once involved with building a vehicle (OEM shall not be named) which was not orderable. It was for an executive's wife who wanted heated seats with cloth interior as she did not like leather. This meant having the seats built as heated cloth and walking the car through the process to insure all of the parts to support heated cloth seats were installed. This is a huge PITA.

When people hear about these kinds of things they assume any dealer could order and have built anything the customer wanted, this is simply not true. The example above took a lot of effort to make happen. The OEM is simply not going to do that for everyone. They can't manage their manufacturing process if they allowed non approved build combinations.

At times you will see examples of things like the wheels mentioned in one of the earlier posts. These are surly the result of a supply issue. When the plant is out of a particular part, it is better to substitute an in stock part and keep the line running. This is done with engineering approval and is documented. Approval is granted as long as the substituted part meets the engineering requirement for function and reliability. 3.42s would not fall under this exception as it would not meet the functional and reliability requirement needed to get an engineering deviation.

stevengerard

There are lots of examples out there though. I understand heated seats without leather as you are building the seat to "custom" specs. But grabbing a rear end off the part bin is much different. We have read about some Cutlass' getting cut-out bumpers because of low inventory, Rallye 350s with chrome bumper bolts instead of yellow, different wheels, even using red inner fender wells on the first few 72 W30s black on the rest. Now granted these might have been "factory approvals" by the powers to be but I'm sure there were plenty of other examples.

I have seen a lot of convertible 442s with different emblems on the door panels. Have they been changed wrongly over the years or were what ever emblem available put on (Rocket vs. C/S). I would guess wrongly changed but I have had too many long time owners say "nope, car came that way"

With my car having a W27 rear-end I think it would be easy to say the factory was short on 3.23s and they threw on the 3.42 because it was there. Then again since it is a W27 I think one could easily argue it was thrown on at the dealer or day 2 just as easily.

I'm reading "On a Clear Day You Can See General Motors" its amazing a car even got built with GMs lack of inventory tracking. Chevy's had 179 engines and 142 axle combinations in 1969. Trucks had 299 combinations and 440 axles, Camaro's had 2,720 possible combinations of dashboards, by 1972 it was down to 96 - it was crazy

Boiler_81

I cant say for 1970 as I was not in a plant until 1981 but something like using 3.42s would not be approved (81 to present) under deviation if it was not released as a buildable vehicle due to engineering concerns with overheating. Maybe some of the board members who worked in Lansing during that time period could give us their thoughts.

Parts substitutions occur even today if fit and function are not impacted. Also cosmetics are a concern now and were not in the past. An example from the Corvette world is big block hoods on 67 small block cars. This really threw the NCRS folks for a loop. It was finally discovered that there was a shortage of small block hoods during a short period of time and Big Block hoods were substituted.

The seat example was put out there for the people who keep preaching the factory would do anything if a dealer ordered it. That is simple not the case. It is impossible to build a bunch of one offs. Mass customization is the ultimate goal of consumer goods manufacturers but is constrained by the realities of mass manufacturing.

wmachine

Of course there were all kind of anomalies out there. But there is a huge difference between the existence of anomalies and "anything was possible".
Now a days, "anything was possible" is used more for a weak argument to support that something happened that didn't. And for every actual deviation that really happened, there are 1,000 claims of more deviations that didn't happen. As a skilled researcher, you have to look for proof to prevent truth decay. And one of the most flawed forms of proof is human memory. IIRC.

pogo69

I agree in some situations/arguments using the phrase '' anything possible'' might be a tool for someone and you are right they are anomalies but i view it in a very broad sense that some parts would show up where they shouldnt and documentation puts any argument in place, but i think of myself being 20 25 years old working on an assembly line in the 60's or 70's had maybe a joint at lunch and the inspector was on a quaalude... blah, **** happens

stevengerard

Not to beat a dead horse but I agree that too many folks assume it was an "assembly line deviation" when in fact it was a change made days, months or years after the car was sold. I can't tell you how many people tell me their 1970 A-body has all the original body panels yet it clearly has a drivers side 1971/72 fender. An Aquantiance of mine has a 70 442 pace car and tells me everyone assumes it is original since he redid it in 1978. He thinks it is pretty spot-on but it was so long ago he has no idea how accurate it really is and no matter what its not original anymore.

So I'm with you guys saying less of this happened then is claimed but as I can attest through my earlier post in this thread my windshield fluid bottle is mounted on the wrong side and always was.

Boiler_81

I fully believe your washer bottle was placed on the wrong side. It would have been an easy mistake to make as most of the cars being built would have been 350s and had the bottle on that side. It wouldn't have been worth fixing even if the inspector had caught it. It is the major deviation claims that drive me nuts.

Many years ago I judged the Canadian Olds Club meet in the stock 442 class. There was a very nice car entered with headers installed. The owner claimed they were factory. It turns his claim of factory was based on the original dealer installing them prior to delivery. Clearly they were not factory installed and just because it was a dealer who put them on instead of Joe Bob's speed shop did not make them any more correct. Heck, I bet the dealer would have gone down the street and obtained a 426 Hemi from the local Chrysler dealer and installed it, if he was paid enough. The guy could have owned the only "factory 426 Hemi W-30"!

Getting back to the 3.42s, it would be interesting if someone gathered the data for the suspected 3.42 AC cars. You would need build dates of vehicles and the axle codes. If a pattern emerged it may lead to some new questions and maybe conclusions. The example of the big block hoods on small block cars was a huge deal for NCRS until patterns were shown in the data.

66-3X2 442

With the 3.42 TM code rear being a W-30 code only,makes me wonder what are the odds of the 5 or 6 cars that I have seen or know of had somebody go out and find a 70 TM code rear and put them in the cars. Again,I have seen the assembly manual that says no 3.42 rears in A/C and dealers not to install them. Didn't GM say no more than 400 CI engines in 68/69 A-Body Olds? Were the Hurst cars shipped to Demmer with the 455 engines or not? I wish 507 OLDS/Brian Trick would respond to this subject,I believe he knows of such a car that has 3.42 gears and A/C.

rand5204

Just to add to the discussion - primarily about parts availability at the plant. I put my self through college in the mid '70's by selling new Fords. I was gearhead even back then and my daily driver was a platinum '70 w30 that I bought in '71.

I worked at a very large dealership. When the sales manager would get tired of ordering new cars (it was still a paper process then) he would come out and give some of the sales staff order forms and tells us to order 30 Mustangs, 40 Torinos, etc. At that time Ford would still paint a car any color you wanted with any combination of interior, vinyl top and body side molding as long as you checked the right boxes on the forms. Sometimes when the transport trucks would arrive with the cars you ordered on them you would hope that no one would trace the combination back to you. Funny thing was those cars always sold. Someone always thought they were a great combination. We actually had a customer order an orange van with a green interior. It came in exactly the way he ordered it and he was thrilled with it.

The other thing that happened pretty regularly ( and this is more appropriate to this discussion) was the odd things that would happen at the end of each model year. It was never unusual to see a car come in with next years interior or grilles or bumper. It wasn't quite as common with mechanical parts but it did happen as well. Just try explaining to a show judge that your '70 442 came from the factory with a '71 rear bumper! It was happening when I was selling cars so it wouldn't be too much of a stretch to believe that it was a lot more common then we might think. I also seriously doubt that this situation was unique to Ford. If they were doing it, all of them were?

BlackGold

Don't go away mad.
I appreciate you sharing with us the cars you've seen. And I agree it seems odd that the 3.42 rears they have are all TM codes, W-30 specific. I'm just suggesting that at least one of those W-30s should have documentation (window sticker, dealer invoice, etc.) listing the 3.42 rear if it was indeed factory-installed.

For what it's worth, my '70 W-30 with A/C has the required 3.23 rear, and has the Car Shipping Order proving it was built this way.

For those of you wondering why all cars with A/C or HD cooling were limited to 3.23 gears, I believe it was because these cars used a pulley set which OVERdrove the water pump instead of the UNDERdrive arrangement on all other cars. The water pump was overdriven because these cars used the thermal fan clutch, which naturally spins slower than the water pump (unless engaged). At idle speeds, a fan with thermal clutch will actually cool worse than a non-clutched fan, unless you overdrive it (or unless it's engaged). So why limit the gears to 3.23? Because the combination of even lower gears and the overdrive pulleys will cause the water pump to spend too much time cavitating. All water pump and pulley combinations probably cavitate at really high RPMs under WOT; you just don't want that to be the normal case at cruise on the highway. That's my theory, anyway.

And yes, the Hurst/Oldses left the factory with the 455 already installed.

TK-65

And one of the most flawed forms of proof is human memory.

Boiler_81

No doubt those things happened, if the odd color combinations were released as buildable combinations then you could order it. Also prior year and next year parts being used is documented. Assembly errors like the washer bottle on the wrong side also happen. However, putting 3.42s in AC cars does not appear to fit any of those cases.

There is no known documentation showing the release of 3.42 and AC. That is why this is a mystery. Were they put in by the dealer? Were they later substitutions? Was there a temporary deviation for a supply issue? The only way to answer these questions is to do the research by gathering data from the cars with 3.42s.

I have been moderating a thread where I have gathered carburetor build dates vs vehicle assembly dates for 70 W-30 automatic cars. While we only have a few cars documented we have discovered some new information and see some pattern to the data. We have found carburetor build dates which had not been previously documented.

If some one were to start a thread and gather data on 3.42 AC cars we might be able to put this to rest. Data is king.

m455sx

i adding myself to the discussion. I believe the factory installed the TM rear at the factory. Also you have a better chance on finding a Lasing build sheet than proving what was done at the factory about the TM rear A/C dilemma....LOL

66-3X2 442

No way I'm mad about this or anything else car related. I'm just telling what I have seen or know about this subject. When I bought the 70 W-30 with 3.42 rear and A/C,I had never heard about that it wasn't available. I'm into 66's,so it was greek to me. I talked to 507Olds/Brian Trick and he told me of another 70 like it. When I advertised the car for sale,that's when I first heard about it wasn't possible. It was debated around various sites and a couple of other guys said that had also seen one. Dr Dan over on ROP says he maintains a 70 W-30 Conv. with 3.42 gears and A/C. There was a 70 W-30 Sport Coupe for sale in MA. It was a A/C car with a TM coded rear. Like I said,it doesn't make one bit of difference to me either way,I just love learning about these cars. I used the Hurst Olds analogy to show that sometimes GM didn't know everything that went on back in the day. I have studied the 66 assembly manual for years and still find things that don't jive.

stevengerard

I was just thinking that - its hard enough to document a W30 let alone what came on it. Brian and others have told me they have seen the same thing be it SX or TM coded rear ends on AC cars

For the record November 18 1969 Build date rear end code SX

wmachine

Exactly. There has to be a systematic (and factual) approach to get any real answers. Mike raised the question, now to gather some data.
https://classicoldsmobile.com/forums...-codes-ac.html

wmachine

More answers require more questions.

What is the difference between SH and TM stamped rears? Both are 3.42
Both are identified as G92 axles.

What is the difference between SJ ans TO stamped rears? Both are 3.91.
Both are identified as G88 axles.

All of the above are identified as the HD units (HD shafts and G80).

So what is different about the above axles that go into the W-cars?

This may shed some light on the thread subject. I haven't had time to really dig into this.

(And probably unrelated, why was the G88 3.91 not available in the non-W 442? When it was available in the other A-bodies *and* the non-442 could have 4.33/4.66/5.00?

jensenracing77

I have recently discovered that all the TM, TO, and all SF rear ends have white paint on the axles. I have no documentation but if I read the parts manual right there are two differant part numbers for the axles. I was tipped off to this by another member here last week. I believe the axles were harder in these rears but I do not know this for a fact.

wmachine

Right, that's the "Heavy Duty shafts" referred to in the product descriptions. But should be the TM, TO, SH, and SJ, not the SF which is a 3.23 rear.

Technically, I don't believe the HD axles were harder, but rather "higher strength" which is not really a technical term. Making them simply harder would not really work well, because there would be no ductility and they would snap with any sudden torsional impact, which is what happens when you launch. Harder is simply more tensile strength. Which more of alone would make them more brittle. Addition "yield" and "elongation" is the trick to higher strength needed to keep them functional.
In '66, the W30s had special axles. Were supposed to be "higher strength". I have not been able to find out exactly what the axle properties were, but I'm guessing they were simple harder. In the '67 W30s, they went back to the regular axles, as I suspect they found the special axles in '66 to be counterproductive.

BlackGold

If it's true that the axles in the TM and TO rear ends were no stronger than in SH and SJ (speculation), then it's possible that the difference was something as simple as tighter tolerances on the set-up (backlash, etc.). But that's just speculation on my part.

I'll do a little digging in the parts catalogs when I get a chance to see if any different parts are called out. But I'm not optimistic I'll find anything.

I know of at least one person who frequents this message board and has an original factory assembly manual for rear ends. I would think it would spell out any differences, at least by identifying different part numbers (even if it doesn't explain what exactly is different between the parts). Maybe he'll see this post.

pogo69

i'm guessing the opposite, but i have no clue really but since the h/o's had beefier everything and high nickel blocks i'm thinking the sh sj and sl were beefed up also, but olds made a lot more of the t rears for the w cars which were raced a lot, so... i never knew why there were two rears coded differntly

Hairy Olds

This is out of my Product Information Manual. No such thing as a assembly manual!

66-3X2 442

Looks like there is no difference in the axles or carrier etc. Am I reading it right?

Hairy Olds

More info Mike.

wmachine

So in addition to the TM, TO, SH, and S rears, the SF 3.23 also shares the same axle.

Yes, Mike. And it now looks like what makes the TM and TO different than the SH and S rears are the brake assemblies and nothing more.

BlackGold

I confirm that the axle shafts in the SF (3.23 posi) rear have the white stripes and thus are the 403304 assembly, which the Product Information Manual says was also used in the 3.42, and 3.91 rears -- regardless of whether or not it was a W-car.

I wonder what was different about the brake assemblies for the W-cars?

The April 1976 edition Oldsmobile Parts Catalog agrees with what joesw31 posted:
403303 is called out for non-W and non-4-speed applications
403304 is called out for W-car and 4-speed applications.
This implies that, while the factory may have put the same heavy-duty axles in both, the service replacement was changed for the less demanding applications.

One other related tidbit:
The 1970 Assembly Manual -- er, Product Information Manual -- section 4 page 93, in the revision history at the bottom of the page you can see that the SH and SJ (3.42 and 3.91 posi, non-W) were added on 9-19-69, while the TM and TO (3.42 and 3.91 posi W-car) were already present at that date. Hmmmm. Also, the SF (3.23 posi) was added on 10-1-69.

66-3X2 442

This is the classic example of factory literature having discrepancies. This is what I meant by you can't take everything for the absolute truth. Not calling you out on your post,just making the point.

BlackGold

I wonder if the W-car brake linings were supposed to stop the car better or better survive smokey power-braked burn-outs.

66-3X2 442

It could be that the W brakes were of a semi/full metallic compound. That was the ticket back in the day.