thanks. so what is it then its only since i came on here that iv been told its a 9 3/8 the only numbers i can find are 406208 and a b i need to confirm so i can advertise for parts and know there fit /
I have no idea what that is. It doesn't look like anything I am familiar with. Monzaz is the member who might be able to help.
Perhaps this is a clue to its ID through the 406208 casting number: https://offerup.com/item/detail/658807891/ You can determine the gear ratio by dividing the two 2 digit numbers on the ring gear. Brian and Jim are the real experts in this area. They should have the final word on identification.
The rear is a OLDSMOBILE rear because back in 1965 - 66 when they made the rear it was for the Oldsmobile 88 98 etc ONLY it had a 28 spline pinion and 31 spline , 30 degree axle spline pitch. Bolt in axles with SEALED bearings. In 65-70 era they were in OLDSMOBILE CARS ONLY. Buick had their 9 3/8" rear 10 bolt cover 12 bolt ring gear 1966-1970 era, 30 spline axles BOLT in and this was used for the FULL SIZE BUICK only cars. Pontiac had a 8.875 rear 65-70 era It had 31 spline and 30 degree axle spline pitch same as the Oldsmobile axles. The Pontiac 8.875 rear was for PONTIAC FULL SIZE CARS and low power Oldsmobile FULL SIZE cars... as Pontiac was a step lower in the GM hierarchy in divisions...lol. NOW.... when 1971 rolled around GM was going into Corporate mod. Meaning they were making everything steam lined and all interchangeable parts for all divisions. Tightening up the belt. So... The 9.3 Oldsmobile rear was designated as GM'S premier rear to have. 455 cars FULL SIZE across the board Buick, olds, Pontiac ( B.O.P.) and WAGONS got this rear. Then the Buick 9 3/8" rear WAS DUMPED.... Gone Outta here. sorry After that rear Pontiacs 8.875 rear was most popular it took most of the cars that were 400 and 350 cubes with 4 bbls and BOP full size cars. Finally bring up the low end horse spectrum was the 8.5 10 bolt cover 10 bolt ring gear rear end. ALL low powered cars received this rear and Chevy it was 28 spline axled also... BUT Chevy trucks are still using this rear till 2021 today... and that is 5000 pound easy so you can be ok with the 8.5 rear and you can get parts for it also. NOW interchangeability was you could take anyone of these rear in 1971 FULL SIZE CARS and pop them in and out complete drum to drum ...All mounting points and drive shaft lengths etc should be all pretty close to identical. Shocks lower and upper control arms they all had constant velocity joints etc. Interchangeability from 1965-1970 and 1971 - 1976 ( 9.3 or 8.875 ) The ring and pinion from the 9.3 and early and late can be done. Pinion yokes have to be kept with there pinion splines. so old 9.3 had 28 spline pinion and the later model 9.3 had 30 spline yoke coupler. (8.5 yoke interchanges perfectly on the 9.3 if you need a regular u-joint to yoke set-up. 8.875 Pontiac is the same deal all ring and pinions interchange except for the 28 spline old yoke to the newer era 1971 -1976 30 spline yoke coupler. Seals are the same 2043 (same as the 8.5 corp rear like 71 72 Buick skylark.) So I hope this helps you ALL figure out what you can and can not do with these Full size car rears. YOU CAN FIND THE 9.3 posi units...It is much harder to find BUT you can STILL FIND THEM. they will be a 's' spring type unit like the 8.5 rear BUT will have 12 bolts on the ring flange of the carrier of coarse...MAKING it a true 12 bolt rear. with 12 bolt cover. Fingers are tired from pecking on the keyboard... later guys have to work now. Jim Mitschke JD Race
pictures The unit with the purple springs is a YUKON DURA grip and is for a 12 bolt chevy 1965-1972 era chevelle / elcamino - or 1965-1970 Impala or 1970-1972 Monte carlo or 1965-1972 Nova or 1967-1970 camaro. Jim
The casting number is from a 1971- 1976 12 bolt OLDSMOBILE rear end 12 bolt ring / 7/16" x 20 ring gear bolts left hand thread bolts, Ring diameter is 9.3" and the pinion spline is 30 spline as stated earlier post of mine. as stated earlier these rears can be found in all 455 cars in the 1971 1976 era FULL SIZE buick Olds Pontiac cars and WAGONS. You can steal the guts from any of the 9.3 rears and use the guts in your 9.3 Posi and open carriers have carrier breaks. 2.56 - 2.73 2 series 2.93 - 3.08 3 series 3.23 - 3.42 4 series I am not sure the break on this rear just have not parted out that many to get total details on it. reference pictures on different height carrier breaks. Jim JD Race
Thanks jim my yukon dura grip is there anything on it that i can use in my axle 4,11 gears etc or is it poss to fit and adapt also iv been offered a spartan mini spool could this work? just need low gears and some sort of posi/spool/locker thanks for all the response
No, no, no..... Nothing fits this rear. Asking over and over will not make the parts fit....lol Sell the 12 bolt Chevy Yukon to a Chevy guy and keep looking for your parts in junk yards and on line etc. OR swap the complete rear end for a 8.5 rear. There is no spartan locker or mini spool , no posi, no gear nothing that fits this rear but it own stuff from the factory. IF there was I certainly would be selling it to you. LArryb, WHAT CAR DO YOU HAVE? what is it your trying to buy a rear end to fit?
Larryb, The definition of insanity is doing the same thing, in this case, asking the same question, over and over, and expecting a different result/answer every time.
Remember I'm based in the UK there are no scrap yards to buy from , no one over here knows anything about these axles so I'm asking you the experts to help , my car is a hot rod gasser a 1938 nash laffyatte coupe with a b/b chevy 496 stroker with a tunnel ram and twin predators backed up by a turbo 400 auto box now I'm 69 iv been building hot rods all my life yes i could go get a chevy or 9 inch axle but i don't want to i will find a way to sort this axle its now in the car on leaf springs , ladder bars etc and painted i can run it as it is till i get the bits for the diff but i will explore every avenue till iv got it how i want it , if i don't ask i don't know thats how i learn i can't just send it to a shop to sort there are no shops here i will be doing it as Jim said someone somewhere will have what i need and he will look out for it for me i thank him for that but i will also look every where i can as well , happy to sell my posi no proBs just Thort i might be able to barstarise it to fit same as the spartan spool I'm asking for help from car people
NOW that is Cool as Sh-T .... That thing needs a 9.3 Olds Pontiac drop out gasser rear end WISH you were not so far across the pond... It would be fun to narrow a housing and get a proper Gasser rear in that ride. Jim
Cheers Jim. Yes would be good if i was over there but I'm not so see what you can find for me posi , low gears etc
yes green flake with silver flake roll cage then a polished ali interia to go in with ali bomber seats i like loud lol
I believe this only fits the 57-64 third member 9.3" rears. https://fabcraftmetalworks.com/product/rear-axlera5-93031-2/
yes i tend to agree i just wondered if it could be made to go into my casing with is later and rear entry NEW POSI UNIT FOR THE 9.3 !!!! FABCRAFT’S EXCLUSIVE TROPHY TRACK SPECIAL LIMITED-SLIP CARRIER FOR YOUR ’57-’64 OLDSMOBILE /PONTIAC 9.3″ REAR END FEATURING: -ALL INTERNAL COMPONENTS MADE FROM AISI 9310 ALLOY STEEL -HIGH IMPACT 6 GEAR DIFFERENTIAL DESIGN -LARGE DIAMETER DUAL CROSS SHAFTS -HIGH DENSITY DUCTILE IRON CASE (STRESS FREE DESIGN) -INCREASED CARRIER BEARING HUB SIZE -ACCEPTS STOCK & AFTERMARKET 31 SPLINE AXLE CONFIGURATION – SERIES II AND III CARRIERS AVAILABLE MAKING THE TROPHY TRACK COMPATIBLE WITH GEAR RATIOS FROM 2.69 THRU 6.14 -BEST TORQUE BIAS CAPABILITY IN THE INDUSTRY -ALL MADE IN THE USA – START TO FINISH !
