Technical Pontiac/Olds Rearend TECH...post it here...

Brad at Fabcraft has everything you need for the olds rearends 800 208 8242

 

Thanks to all you guys for that info. I'll make the calls... MAGOOZ

 

Just orders fabcrafts book on these rearends.I called to ask a few dumb ?s.Anyway to order anything from them you should call them I saved about 5 BUCKS by calling them.eBay charges you and him.so just a heads up guys.

 

I just recently made a purchase from Gevo and, I'm way more than happy! Good prices, good parts and, John is a good guy! I'll be dealing with him in the future!


Dustin

 

Gevo, do you know specifics about whats involved in the changes necessary to use the 8 3/4 mopar diff in the '48-'56 rear? I understand theres some machining involved?

 

Wow that a lot of good info, thanks!

 

I've got a 53 and a 56 olds rears. the 53 has 3.64 gears and the 56 has 3.42. i'd like to run the 53, but its got that flat type yoke and I'm having trouble finding the u joint for it. the 56 has a normal gm looking yoke that uses 2 u-bolts. can i simply move the yoke from the 56 to the 53 pinion shaft? I guess it's not a huge loss as I'll get better economy with the 3.42s, but im just curious. thanks in advance!

 

The swap will work , make sure to measure the rotating torque at the pinion in inch pounds before you pull it apart to get the pinion setting back to where it was.

Where are you looking for a ujoint ? Looks like rock auto had a listing for the olds Moog/precision # 531g. Napa showed the u joint as well under that number.

 

thanks, now to find bearings for this damn thing...

anyone know if the early rear ends use the same bearings as the 57-64? I have all my old bearings/races out, mic'ed them, and the my carrier race measures 3.051" OD and the skf number listed earlier in the thread says 3.265" OD

 

I`m sorry I don`t. To be honest I`ve never heard of it being done.

 

In 49-56 , the earlier years ( not sure what year the break is ) had 10 spline pinion , later had 13 spline pinion.I believe 3.051 is the 10 spline and 3.265 is the 13 spline.

 

These are the Napa numbers I had for 47-56 rear. The earlier version 37-47 had ball bearings for the pinion.

Front pinion bearing BR31590/BR31520
Rear pinion bearing BR3779/BR3720
Differential side bearings BR25584/BR25520

 

57-64 pontiac /olds 9.3 incher..when only the best will do..anybody got a mag center section for one?..

i second the nomination for fabcraft..that cat is serious about rear-end pieces..

gevo, do you have any posis for sale, 31 spline, 59-64?

 

gevo and 55 cheiftain-thanks for the quick responses. I really appreciate it. I'm a tech student, so while everyone else is rebuilding junkyard s10 rears, I'm getting class credit for overhauling my old junk. My instructor has a 64 Grand Prix that i get to do next-I'd really like to have that one.

 

If I were to buy a complete from drum to drum 57-58 Olds non-posi rear end, what is the average or good buying price for one?


Dustin

 

1957 is last year for leaf springs and the are bolt on chevy 55-57.it is the most disired rearend .french lake in minesota have several and the ship .
here in sweden i cant find any.i did buy one of a hamb member in texas.i payed 600dollar and shipped with my cars to sweden.
picture is from my safari 1957

 

You're half right.... I wasn't asking about a Pontiac rear end. OLDS had leaf spring rear ends up until 1960. The 1957-1958 non posi rear ends is what I'm asking about. 57-58 Olds were the same widths as each other and I believe they bolt under 55-57 Chevys as well. 59-60 the Olds rear ends got wider. Someone can correct me if I'm wrong.


Dustin

 

The yokes [flanges] will interchange with no problem but if you would rather keep the 53 flange and need a new U-joint, try a farm implement dealer.
I got stuck in Springfield, Illinois with a worn out U-joint in my 48 Pontiac. The local NAPA sent me to a local implement dealer [may have been John Deere, can't remember for sure] and they sold me a new one for triple-cheap..said it was the most common ujoint they sell.
I put a 56 Pontiac third member in my 41 Pontiac and had to swap out the 56 flange for the 55 and earlier flange to keep my 41 driveshaft. Took 5 minutes and it was a good opportunity to change the pinion seal.

 

well, Differential side bearings BR25584/BR25520 doesn't fit the 53 olds-maybe its a pontiac? any one have part numbers for them

 

My source( napa catalog) lists the same olds side bearings for 53-64? Your positive it's a 53 rear? I don't have a listing for 62 and older on side bearings, only pinion bearings. Can you get the numbers off the old stuff and try to cross referance?

 

i was able to find them, but they want $340 a side for the carrier bearings straight from timkin...the napa catalog is wrong. at school here i have my 53 pontiac, my 56 olds, and my instructors 64 grand prix, and the bearings are all the same, yet none of the one napa listed fit-go figure.

 

If you own one of these rear ends, do yourself a favor and pick up the Fabcraft manual. Everything you need in a very professional color print. Worth every penny.
Thanks Fabcraft!

 

The rear end in my '56 Olds seems to leak.
First I thought it was oil from the rear main (engine) leak, but now that I've looked closer it looks to be the rear.
Is there a common issue on these rears?
Can I just change the gasket of the third member and that should take care or it?

Sorry if those seem like stupid questions, I've never really messed with rears...

 

I would tend to think it is the pinion seal.
If you have never replaced one, I would pay someone who knows how to do it properly.
KK

 

Anyone know what the chances are of a 1963 Grand Prix being a posi is? Everything is very rusty and I haven't had time to pop out the center chunk yet.


Dustin

 

About 10%. Auburn is set to begin production of new 9.3 carriers. Superior to the originals, they are the usual over engineered parts you get from Fabcraft. Years in the making, they [Fabcraft] did a great job designing the new carrier. http://fabcraftmetalworks.com/cgi/commerce.cgi?preadd=action&key=RA5-93031-2 Tell Brad that Dave Johnson sent you.

 

I knew about the 10% part but, it seemed like every 63 GP I looked up online, had the Safe-T-Track.... Wishful thinking. I did not know about Auburn and Fabcraft making and selling a posi. Thanks for all the info Dave!


Dustin

 

I would bet the odds of finding a posi in a GP are considerably higher. GP's were expensive, high option, that were marketed as performance cars.

 

Higher chance if we knew the car is tri-power or stick. Under 7% of 63 GPs were stick. The 3 63 GPs I've owned were open rear. Maybe the 4th would have been ls, so that gets us down to 25%. How many GPs are left and not picked for an ls rear after 50 years? Not many. Fingers crossed for you, jade. Check that Auburn if it doesn't work out for ya. Preproduction orders get a discount.

 

I just put posi and higher gears in my 64 from fabcraft. Whole new car. I can get most of the torque to the ground now from my built 389. I highly recommend Fabcraft they are creat and very knowledgeable!!


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