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I have acquired a 31 spline "O" rear 3:90 posi. I'm hoping to speak with someone knowledgible about these rears.I have been doing rears for 40 years and this is only the 3rd one I have encountered.This particular rear I'm sure has never been opened up until now.I say this because it still had the black heavy gear lube I'm used to seeing in only older rears.All the bearings and seals are OE.There are some paint marks near the yoke.In any rear ,especially one that was used hard there is always metal transfer on the mating surface of the upper left cap mating surface.This is the highest stress point,this rear has a special bolt in that position.I think this rear is a good candidate to learn from.This rear will be for sale,but I want to know more about it first.
Last edited by SmirchIs#1; October 3rd, 2018 at 07:12 PM.
Reason: bad picture
I have acquired a 31 spline "O" rear 3:90 posi. I'm hoping to speak with someone knowledgible about these rears.I have been doing rears for 40 years and this is only the 3rd one I have encountered.This particular rear I'm sure has never been opened up until now.I say this because it still had the black heavy gear lube I'm used to seeing in only older rears.All the bearings and seals are OE.There are some paint marks near the yoke.In any rear ,especially one that was used hard there is always metal transfer on the mating surface of the upper left cap mating surface.This is the highest stress point,this rear has a special bolt in that position.I think this rear is a good candidate to learn from.This rear will be for sale,but I want to know more about it first.
The 31 spline axles were only used in 67/68. It's actually called a 3.91 but that's not important. The T3 code was also used in 69 but as a 28 spline unit.
672 is the only limited slip casting for the 31 spline. Meaning you can only use 3.42 3.90 4.33 4.66 5.00 ratios
Axle bearings are sealed rw507cr
Again this was a W30 only option 1967 1968 years.
CArrier bearings are LARGER in this housing as it uses the larger 3.062/3 carrier saddle diameter where as all the rest use the smaller 10 bolt carrier bearing diameter of 2.890 saddle . because they only had 28 spline axle shafts
Clutches are interchangeable with the other 2 3 4 series 28 spline units too.
672 is the only limited slip casting for the 31 spline. Meaning you can only use 3.42 3.90 4.33 4.66 5.00 ratios
Axle bearings are sealed rw507cr
Again this was a W30 only option 1967 1968 years.
CArrier bearings are LARGER in this housing as it uses the larger 3.062/3 carrier saddle diameter where as all the rest use the smaller 10 bolt carrier bearing diameter of 2.890 saddle . because they only had 28 spline axle shafts
Clutches are interchangeable with the other 2 3 4 series 28 spline units too.
Jim
J D Race
Where did you get the info that the 31 spline axle was a W-30 option only in 67/78?
Just sales info from brochures I am sure as long as your ordering the car you could get the 31 spline option....money talks! I assume you mean 67 / 68
The 31 spline was only in 67 / 68 for sure.
Jim
J D
Last edited by monzaz; October 5th, 2018 at 11:51 AM.
Just sales info from brochures I am sure as long as your ordering the car you could get the 31 spline option....money talks!
Jim
J D
My knowledge about them is,every 67/68 3.42 and lower gears got the 31 splines. There is no W-30 codes specifically for the 67/68 W-30 like the later W-30 axles. Maybe one of the 67/68 gurus can add to this.
Seems as if you already know a lot about it. What additional info are you looking for?
Specifically,I was wondering if the paint marks are of any signifigance,also the fact that the upper left diff cap bolt is different.I thought this rear may be a good candidate to learn from as I'm sure it has never been apart
672 is the only limited slip casting for the 31 spline. Meaning you can only use 3.42 3.90 4.33 4.66 5.00 ratios
Axle bearings are sealed rw507cr
Again this was a W30 only option 1967 1968 years.
CArrier bearings are LARGER in this housing as it uses the larger 3.062/3 carrier saddle diameter where as all the rest use the smaller 10 bolt carrier bearing diameter of 2.890 saddle . because they only had 28 spline axle shafts
Clutches are interchangeable with the other 2 3 4 series 28 spline units too.
Jim
J D Race
Thanks for all that knowledge that anyone who has decades of experience,like myself would already know.My post stated that all bearings and seals were original GM,so how would I have made that determination.Do you even read a post completely before answering
Specifically,I was wondering if the paint marks are of any signifigance,also the fact that the upper left diff cap bolt is different.I thought this rear may be a good candidate to learn from as I'm sure it has never been apart
If you look close at it ...it appears the bolt head was shaved lower and dimpled? For some reason someone did this? That is not the way any bolt comes from the GM factory.
Paint marks... always mean something... I know GTO guys get that info for their cars there were paint swaps on th e outside and in th e case. I know on the caps GM will make a paint mark so you can install the caps back on correctly...BUT years of oil changes and people cleaning with brake cleaner marks disappear and the reason we punch the one cap and reference to th e case adjacent to the cap.
Last edited by monzaz; October 9th, 2018 at 09:01 AM.
wE HAVE HEARD THAT ALSO AT LEAST THE FIRST HALF OF 67 for sure. darn caps...
64 65 GTO also shared the Olds rear in those years as Pontiac did not have its own rear back then either.
Jim
wE HAVE HEARD THAT ALSO AT LEAST THE FIRST HALF OF 67 for sure. darn caps...
64 65 GTO also shared the Olds rear in those years as Pontiac did not have its own rear back then either.
Jim
Where do you keep getting this info from? Olds didn't have a dedicated rear axle till 66 when the O Type was introduced. The 64/65/66/67 10 bolt axles were B or P 8.2 axles.
You do not work on differentials, do you? your info is WRONG. 1964 1965 there was only a Buick and a Olds rear. NO PONTIAC rear. in 1963 Pontiac had a trans diff independent rear. Skylark and F85 were the only A-bodys that exsited before that ...SO how could PONTIAC even have a solid axle rear before Olds and Buick? 1964 was the first year for the GTO it used the a-body rears that were available at that time (Buick and Olds). Which was the Skylark and F85 rear. in 1964 the upper control arm bushings were 1" diameter and Buick only then in 1965 another rear was produced by GM for the Olds and was shared by the GTO as its HD rear for the Olds high powered cars. Lemans and tempest just used the Buck 8.2 rear (considered the BASE rear for a-body chassis till 1967) that had less beefy bearing caps. Buick GS had a Modified Buick rear that used the larger a body wagon axles and bearing system (ONLY GS BUICK) The 65 Olds rear had the pre Pontiac bearing caps which were thicker and wider (did not have the < > castings on the caps just a part number) . Then in late 65 early 66 Pontiac got its own rear with casting upgrades caps got the < > castings on the bearing caps Pontiac also had the converging upper webbing from th e upper bushing casting to the pinion snout area. Buick only had the lower webbing from the axle tub pressing are to the pinion snout and OLDS 65 rear had the lower webbing like the Buick AND a vertical passenger side webbing at the pinion shout area. and the casting number was at the bottom of the center section casting facing the ground. Pontiac 8.2 We consider the strongest 8.2 in the early a-body rears. That is why Pontiac used it till 1972 they only change the ring gear bolts in late 69 early 70 to th e 7/16" left hand thread bolts. and also changed the axle bearings to oiled system type.
There is MORE but I am tired of writing.
It is all experience info from 35 year of disassembling and building rears. ANYthing else on these cars...You guys can be the experts.
Have a good evening. Jim
PS what is the deal with your AVATAR? Please explain that for all of us. Cause I must be taking the confederate flag and your comment on terrorism the Wrong way?? does not seem to go together...
Last edited by monzaz; October 9th, 2018 at 08:57 PM.
The Olds parts books show B and P axles under gear sets, Group 5.529, beginning in 1964. No O axle until late 1966. A Service Guild Bulletin dated May 1966 introduces the O axle.
The Olds parts books show B and P axles under gear sets, Group 5.529, beginning in 1964. No O axle until late 1966. A Service Guild Bulletin dated May 1966 introduces the O axle.
Thanks Dad for that info. When you have followed these cars for over 40 + years like we have,you learn something.
You do not work on differentials, do you? your info is WRONG. 1964 1965 there was only a Buick and a Olds rear. NO PONTIAC rear. in 1963 Pontiac had a trans diff independent rear. Skylark and F85 were the only A-bodys that exsited before that ...SO how could PONTIAC even have a solid axle rear before Olds and Buick? 1964 was the first year for the GTO it used the a-body rears that were available at that time (Buick and Olds). Which was the Skylark and F85 rear. in 1964 the upper control arm bushings were 1" diameter and Buick only then in 1965 another rear was produced by GM for the Olds and was shared by the GTO as its HD rear for the Olds high powered cars. Lemans and tempest just used the Buck 8.2 rear (considered the BASE rear for a-body chassis till 1967) that had less beefy bearing caps. Buick GS had a Modified Buick rear that used the larger a body wagon axles and bearing system (ONLY GS BUICK) The 65 Olds rear had the pre Pontiac bearing caps which were thicker and wider (did not have the < > castings on the caps just a part number) . Then in late 65 early 66 Pontiac got its own rear with casting upgrades caps got the < > castings on the bearing caps Pontiac also had the converging upper webbing from th e upper bushing casting to the pinion snout area. Buick only had the lower webbing from the axle tub pressing are to the pinion snout and OLDS 65 rear had the lower webbing like the Buick AND a vertical passenger side webbing at the pinion shout area. and the casting number was at the bottom of the center section casting facing the ground. Pontiac 8.2 We consider the strongest 8.2 in the early a-body rears. That is why Pontiac used it till 1972 they only change the ring gear bolts in late 69 early 70 to th e 7/16" left hand thread bolts. and also changed the axle bearings to oiled system type.
There is MORE but I am tired of writing.
It is all experience info from 35 year of disassembling and building rears. ANYthing else on these cars...You guys can be the experts.
Have a good evening. Jim
PS what is the deal with your AVATAR? Please explain that for all of us. Cause I must be taking the confederate flag and your comment on terrorism the Wrong way?? does not seem to go together...
The avatar is self explanatory,it's a southern thing,you wouldn't understand. Did you see RunToRund comment on the gear set info straight out of the GM parts book?
Forgot to mention to check the original rear end cover to see if there is a "T3" in paint. There might be an orange paint square on top of the pumpkin. Can't remember what other definitive paint marks could be there.
On the GTO they had green for the backing plate and upper control arm bushing area pink... Inside the casting of the housing cavity top there are paint marks .
I had example pictures years ago but I think i deleted it as it was never needed for example till TODAY...lol.
Well I have pictures and I actually have the housing ON THE SHELF and will get pictures. I do not go by books here. Actual physical evidence. As the Olds 12 bolt rear in another thread had a flat perch WHICH was NOT suppose to be in existence either...LOL. Books are written BY .... YES humans... AND Yes human error.
Cop out answer. Same thing that is wrong with this country.... STILL divided by crap you can not let go of. War of Southern aggression...lol Let it go....
Cop out answer. Same thing that is wrong with this country.... STILL divided by crap you can not let go of. War of Southern aggression...lol Let it go....
No not a cop out answer. It's really just having fun but if you can't take a joke,well..........
I have no doubt you're a good axle guy but when you make statements for fact that are not true,can't let that go. It's not a matter of trying to prove what I know and you don't or vice versa,no need for false info. That's how some guys learn,reading message boards etc.
No not a cop out answer. It's really just having fun but if you can't take a joke,well..........
I have no doubt you're a good axle guy but when you make statements for fact that are not true,can't let that go. It's not a matter of trying to prove what I know and you don't or vice versa,no need for false info. That's how some guys learn,reading message boards etc.
Not making anything up...there are just things out there that are NOT in books. (guys WILL learn that with more car restoring) The facts are On the rack in the back of our property (as long as we did not sell it yet). I will post the picture... just give me a day here have a few rears to build then I can play. You have Intelligence (books smart) and you have Wisdom ( life experience applying it correctly) AND just because were OLD does not mean were wise...lol.
I do not want to fight about anything... As you, I want the truth and actual real info to be on the board as there is JUST too many false things floating in the internet info stream.
Avartar. - Jokes are all fine (still not really not getting the joke on it) - But there are many people that can not define that line and as a country we need to be clear as to the thoughts that are displayed we have enough with the government ALONE as a JOKE... We the people need to take over and Show what we are... United and together. which unfortunately are not yet. Actions louder than words. AGAIN... not trying to put up a fight...but look at the Avartar in a sense of what it says clearly, NOT what it suppose to mean to you. Everyone is aloud to believe freely what they want... But in public it should be proper to get along respect one another as well as possible. I like jokes ... We DO need to lighten up on many subjects .... but also put the shoes on of the people or group getting joked on then take your consequences I guess.
Too much political I will stop now. Sorry.
Somewhere GM has to have what the different colors mean. I have seen Green Blue Pink Yellow etc.
x and O and slash left and right... inside the case above the carrier.
I have seen these paint marks in 8.2 drop out Chevy Olds Pontiac drop outs all integral up to about the mid seventies... but not later than 80 rears. Only on the caps were paint marked for the 80's and newer from experience...NOT BOOKS to clarify.
Upper driver side bolt
HAve you removed this carrier bolt? Compared to another that was removed? Find it hard to believe they are going to install a special bolt from the factory on a stress point. why not just change them all? Would the cost be that much more? We all know the driver side get hit with more torque load but how far are we going to go with specialty parts from the factory.
I know aftermarket companies make steel caps etc for the driver side etc. - but again from experience the caps are not really failure point on rears - lack of getting gears installed correctly is where they mostly go wrong. We have so many companies now that supply extreme rears all these upgrade are really not necessary. Back in the day all they had was factory stuff and machine shop saw a nitch and ran with it. Now we can not even find a MOM and POP machine shop...
Like Chevy using 'High Impact' gears in 12 bolt Chevy for Some rears in the copo era etc.
Last edited by monzaz; October 10th, 2018 at 12:11 PM.
If you look close at it ...it appears the bolt head was shaved lower and dimpled? For some reason someone did this? That is not the way any bolt comes from the GM factory.
Paint marks... always mean something... I know GTO guys get that info for their cars there were paint swaps on th e outside and in th e case. I know on the caps GM will make a paint mark so you can install the caps back on correctly...BUT years of oil changes and people cleaning with brake cleaner marks disappear and the reason we punch the one cap and reference to th e case adjacent to the cap.
I have taken a closer look at the cap bolt in question and there is no grind or file marks.Again do you even read and digest a post before you run your mouth.I was the 1rst one to ever remove the cover.Where would someone have gotten their hands on that old heavy black tar like gear oil?Why is it you have this need to be accepted as the premier go to guy for rearends?You think you know everything,yet I have seen you post so much incorrect (WRONG) info it blows my mind.What a shame it is for the guys that don't know about rears and want to know more about rears and think that all you say is fact when it is not.Here is one of many examples;You stated that the break in and heating and cooling of a rear adds to the Rockwell hardness of the componants,this is not only false,it's ludicris.It's a good thing you mark your diff caps,as I'm sure you couldn't figure it out otherwise.What if it comes in with the parts in a box or no caps at all?
LOOK AT THE spider gear pictures...lol. They are DONE. Teeth are all chewed up. You said you know rears ... you know those are junk.
So you call my posi unit junk,yet all you see is a couple of blown spiders.Must be true if the great Monzaz says so.For your info the side gears,clutches, case are just fine,and yes I have the capability to magnaflux the parts.Then you have the gall to say I don't know rears.So really I guess that makes you a Moron.I've been biting my tongue since my first post on this website when you jumped all over me then
Well I have pictures and I actually have the housing ON THE SHELF and will get pictures. I do not go by books here. Actual physical evidence. As the Olds 12 bolt rear in another thread had a flat perch WHICH was NOT suppose to be in existence either...LOL. Books are written BY .... YES humans... AND Yes human error.
Again,the O Type axle was introduced in late 66 with a flat perch spring mount and I have had several of them. Who says they didn't exist? They damn sure did and you need to learn you ain't the only guy who has experience. One thing I've noticed about you,you don't like to be informed when you're wrong and you have been wrong several times.
I have taken a closer look at the cap bolt in question and there is no grind or file marks.Again do you even read and digest a post before you run your mouth.I was the 1rst one to ever remove the cover.Where would someone have gotten their hands on that old heavy black tar like gear oil?Why is it you have this need to be accepted as the premier go to guy for rearends?You think you know everything,yet I have seen you post so much incorrect (WRONG) info it blows my mind.What a shame it is for the guys that don't know about rears and want to know more about rears and think that all you say is fact when it is not.Here is one of many examples;You stated that the break in and heating and cooling of a rear adds to the Rockwell hardness of the componants,this is not only false,it's ludicris.It's a good thing you mark your diff caps,as I'm sure you couldn't figure it out otherwise.What if it comes in with the parts in a box or no caps at all?
Lol. Funny guy. Everyone gets there opinions... Discussion forum... your aloud.
Jim
J D Race
Again,the O Type axle was introduced in late 66 with a flat perch spring mount and I have had several of them. Who says they didn't exist? They damn sure did and you need to learn you ain't the only guy who has experience. One thing I've noticed about you,you don't like to be informed when you're wrong and you have been wrong several times.
I am just reading other posts about the M casting rear section - we have had original 67 Olds with Pontiac rears as the HD rear in them from the factory . So who is in control of the rear that goes into a car on the assembly line...(Humans Again) who is to say that goofs do not happen? You can have dates on stuff till your blue but if the plant runs out of rears they are NOT stopping the line they are going to install what they have. 1970 GM strike proved that... Pontiac rears under Chevys and Olds 12 bolts under Pontiac s and El Camino etc.
So not disputing there was not a 12 bolt olds in 1966 with flat perches as Pictures seem to prove that... Just like your going to see the early rear that thought did not exist when I post the pics. There are all kinds of things that are rare and low production pieces that were rethought and formulated because they were wrong or deemed not necessary etc. We are here to DISCUSS all this give the info and weed through the stuff for knowledge.
You just have a problem that if something is not in a book it is not there and that a book can not be wrong... I can WRITE anything so can you and have it printed... does that mean it is RIGHT? So we both have our issues and were both human. Jim
So you call my posi unit junk,yet all you see is a couple of blown spiders.Must be true if the great Monzaz says so.For your info the side gears,clutches, case are just fine,and yes I have the capability to magnaflux the parts.Then you have the gall to say I don't know rears.So really I guess that makes you a Moron.I've been biting my tongue since my first post on this website when you jumped all over me then
Jumped on you ? this is what you wrote . The way you wrote it... You have been doing rears for over 40 years. (know that would mean you know about rears.how MUCH???? ) - You state all this stuff that you know on the rear, a bolt, paint markings on the front nose area, black goop fluid, original bearings etc. THE way it is written you want to know more about the rear NOT the things you have listed....PARDON all of us not reading into what you really wanted to know about on this rear, which WAS the BOLT and the paint markings etc. That post did not come till later in the thread till Oct. 8th. 2018
so we gave more info... .then everything went to hell. Were done. I am apologizing to you for know reading your post the way it was suppose to be read .
Take care, Jim
copied first post - I have acquired a 31 spline "O" rear 3:90 posi. I'm hoping to speak with someone knowledgible about these rears.I have been doing rears for 40 years and this is only the 3rd one I have encountered.This particular rear I'm sure has never been opened up until now.I say this because it still had the black heavy gear lube I'm used to seeing in only older rears.All the bearings and seals are OE.There are some paint marks near the yoke.In any rear ,especially one that was used hard there is always metal transfer on the mating surface of the upper left cap mating surface.This is the highest stress point,this rear has a special bolt in that position.I think this rear is a good candidate to learn from.This rear will be for sale,but I want to know more about it first.
rear pics you wanted - This is the special 65 only GTO rear guys want as it was the only one used in the GTO. Does not have the converging ribs KNOWN with the Pontiac rear and these were used in the Olds HD engine applications we have found them in the 442 also. Seems the Olds and Pontiac still shared the rear end parts here again. It is cast as a Pontiac with the 97 in the casting as most all 8.2 pontiac rears were. ...so There is your B and P no O so there you go, Monzaz is wrong (making everyone happy.) But the A-body Olds used this rear under there cars with the Big motors and the lower powered motored Pontiac and olds got the Buick 8.2 rear. both the buick and This rear use the BUICK type yoke and seal same as in 1964
reason we consider it olds rear is the Buick uses the same pinion seal 8620 Pinion seal and ALL Pontiac 8.2 rears used the 2043 pinion seal (converging diagonal web casting from the upper control arm ears to the pinion snout) just a half breed rear one year only deal shared by the A-body GMS. Pics are there.
you can see it only has one vertical rib on the passenger side of the pinion snout... but not on the other.
October 3rd, 2018, 07:07 PM
