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Gbody rear axle

hi im wanting to put in a posi or locker on my 81 malibu it has the 7.5 10bolt axle lookin for cheaper also car is going to be a daily driver no track and also is there any axle that i can go the the junkyard and get and just remove the internals to swap them thanks n advance.

Monte Carlos will have the same 7.5 rear axle and you may find a better gear set in them. The Buick GN and Olds had the 8.2 or something like that but I think the entire axle will bolt in. Just take a tape measure and measure backing plat to backing plate and see if they match up.

My guess lately, you won’t find anything like this in the junk yards. Craigslist and car specific forums may be a quicker find for this type axle.

ok thanks have u heard of them being hard to drive in rain or snow and making turning of corners difficult becouse they make the car want to go streight posi

The “posi” from a factory car is really a limited slip in which it is supposed to reduce one wheel slipping by itself using clutches or cones to apply movement to both rear wheels. These limited slip axles do not tie the two wheels directly together. There are aftermarket “lockers” that can be installed which make both tires more connected and and in my opinion those would be difficult to drive in the snow. As for the limited slip being more difficult to drive on snow, the limited slip typically seen as a helper in most situations with traction. That said, I have not driven a rear drive car on snow in many years. I live in Alabama so my comment on this would be speculation.

You may want to ask what type of carrier is in the axle if you are buying one used. The seller may or may not know. If you are picking from a salvage yard, block one back tire so it cannot move, make sure the car is in neutral or the driveshaft is already out and that the brakes are free with no parking brake set. Turn the other rear tire by hand with it off the ground. If it moved freely, no limited slip or severely worn limited slip. If it moves but is around 50 lb ft to turn the tire assembly, good limited slip unit. If you cannot turn the other tire, locker is present or something else inside is binding and you need to investigate or move to another axle…

I forgot to mention that removing the internals and placing them into your axle is not an easy task for a novice. I have been messing with cars for better than 25 years and I still let someone else do this internal work for me. There are critical distances that must be kept or the gears inside will eat themselves or be so noisy you cannot hear yourself think. If you can get an entire axle, that is much easier…

And make sure you understand what gear set you are getting in the new axle… It can/will throw off all the speedometer settings and possibly fuel mileage unless you just happen to be lucky and get the same gears. Counting teeth on the gears inside is how you tell the axle ratio. Large ring gear teeth divide by pinion gear. Pinion is what the driveshaft hooks to, ring turns the inside assembly out to the axles and wheels, just in-case you haven’t looked inside before.

ok thanks for all the info i think if i do end up getting one ill take it to a shop and let them have at it thanks again

It’s kind of good to hear from somebody who isn’t mainly concerned about fuel economy. You probably won’t suffer any loss of it, but if you do, I’ll be right here to read about it. I would post a comment about this job you want to do is “just throwing money away” but who needs to overstate the obvious. I have some stuff in my garage that I may never use a second time. So, I have no right to comment. Enjoy this project while I keep mumbling things about interest rates.

I ordered posi traction on my 81 Olds and it was great in snow and ice in Minnesota. The only caution was that you could not use cruise control on slippery roads or the rear end could swing out on you. It was quite an improvement from the standard rear end I had on the previous car. I did have to change rear end fluids and use the additive regularly or you’d get the clicking noise on sharp turns. Now I did have a Buick wagon that I didn’t know the history of but the guy used a welder a lot on it. It was terrible on ice. I’d always suspected that maybe he had welded the axles together or something because it seemed like they were locked together. No way would I want that set up for a driver.