Hi, Can anyone help me identify this rear end in my 66 Wildcat? It has 10 bolts but is very square compared to other GM 10 bolts. I can confirm it is an open axle and has a ratio of around 3.07. Is this the correct rear end for the year and model? I want to rebuild it and install a lsd. Marco
Hi Marco, It's probably the original 9-3/8" housing. There's a bit of bad news - since there are no aftermarket posi carriers or gears available, you're limited to finding donor parts. Also, the '66 carrier is a one-year-only deal because of a design change for '67 that enlarged one of the carrier bearings. So, in effect you're looking for a posi carrier (and maybe the gears too) from a '66 Wildcat, Electra or Riviera (LeSabre won't work). Unfortunately, I don't know if the entire housing from a '67-'70 Wildcat/Electra will bolt in or not. Maybe someone else knows more about what fits the '66. Devon
9 3/8" as stated is correct...and also the 1966 carrier as staed has a early and a late in the SAME 1966 year... carrier bearings early were same size (12 bolt chevy carrier) late BUICK only large on the drive side and smaller on the passenger side NO aftermarket gears or posi units AS stated too . Jsut wanted to let you know as of 1 1 2018 we do not have any BUICK 9 3/8" gears or posi. Sorry Jim J D
Thanks for all the feedback guys, Devon, can I confirm that the '66 non-posi ring will not fit the '66 posi carrier? So I would need to find the carrier and gears? Jim, just some clarification on what you said, is the earlier carrier the same as the chevy 12 bolt carrier? Or just the fact that the carrier bearings are both the same size? Let me confirm the numbers on the casing to post here and make sure I know what I am dealing with before I strip it. Marco
only THE CARRIER BEARINGS AND RACES IN THE early 1ST DEsign... That is it. 2nd design is all on its own carrier bearings gears posi etc. Now as for gears fitting posi or non posi ...THAT is all relevant to the series carrier and gear. You need to keep 2 series gears with 2 series posi or non posi. HAVING posi or non posi makes no difference... it is keeping the series carrier with its correct gear sets that fit that carrier series. Hope that makes sense. Jim JD
Thanks for the clarification regarding the bearings. I understand what you are saying but how would I know what series I have? I have taken some photos and also opened the rear axle up so that you guys can help me identify it properly and confirm that it is in fact a '66 rear end and hasn't already been replaced with another one? It has a PG code stamped under the left axle tube. According to the chassis manual, this makes it a std 3.07, but does it help confirm the year? Is it an early design with same size bearings on both sides of the carrier. I haven't removed the bearing caps but they look to be the same size. Is it possible to confirm from these photos? Do the numbers on the ring gear provide any useful info? The axle shafts have 30 splines, not sure if that info helps. Marco
In the meantime I am also investigating whether it may more feasible to replace the rear axle with another, more common Buick one. My friend has this rear end from an Electra, I am not 100% sure about the model but I think it is a '70. I know it is a non posi and has a very low ratio of about 2.62, not accurate. Can anyone identify the year model based on these numbers I found: Under the axle tube: D 273 On the front of the casing: 1232648 and on the other side: 256 If this is a later axle then is it possible that replacement parts are easier to get then that of a '66? Marco
3.07 so you need to stick with that carrier in a posi unit. CASTING NUMBER 32103 is the posi unit that has the same size bearings left and right. WHICH it looks like from the picture. ONLY way to be absolute is to pull the bearing caps and see. 32120 casting is for the 3.07 posi carrier with different left and right bearing sizes. (more common). All axles 66-70 are 30 spline tooth count is 43 and 14 which if you do the math division it comes to 3.07142 so that rounded out to the second decimal is 3.07. Jim J D
Thanks Jim, I'll remove the carrier to be sure if the bearing match. Would a posi with a casting number of 32086 be correct as well? Marco
You do not need to remove the carrier JUST the caps... If they match you have early if they are different you have late 2 different bearings Carrier is a 2 series you will need a spacer plate for the 3.07 gears. THAT is a custom piece and you will need long bolts also. So really no it will not work as is.
I removed the carrier anyway as I wanted to inspect everything. Both the bearing are the same, the races are LM603012. So it is the earlier design. Thanks for this info Jim. A spacer wouldn't be problem for me, I would get one made cut and rectified on a surface grinder. Do you know what the exact thickness the spacer would need to be? I found this posi on ebay, seems to be what I need but the casting number does not match what you have mentioned. What do you think? https://www.ebay.com/itm/-/282734165076 Marco
I don't know if you can use this or not............https://chicago.craigslist.org/sox/pts/d/oldsmobile-98-buick/6440287209.html
Marco, Regardless of the casting number(s), from appearance and description that looks like the carrier you're looking for. Devon
wrong REAR...SORRY THAT IS A olds 12 BOLT POSI not A buick 9.3 POSI. WILL NOT WORK in the rear pictured. BUICK 10 bolt cover 9.3 is ALL ON ITS OWN. Hope you did not buy.... Jim
Thanks Jim, I was going to buy it but wasn't 100% sure even though the seller is telling me it is the right posi and that it is a 9.375". I have started looking at some alternative axles now.
The posi looks like this...BUICK FULL SIZE use this picture ... rats trying to find the picture I had. The casting number on that 9.3 OLDS will only be 3 digit like 761 or671 or 698 700 something like that. We gave you the correct castings to look for. Unit will only come from a BUICK 66-70 that is it. wildcat, electra, riv etc. BIG CAR
I have a 72 electra with a BOP 12 bolt rear stock 455 2400 stall TA 288 92H cam current 2.73 rear 400 trans should I upgrade to 4l60e with 3.90s?
