Swapping Out Rear Axle Assemblies

[MegaOlds]

I am going to swap out the factory rear axle assembly in my 83 Cutlass to one that came out of a Cutlass that has 373 gears and an 8.5" rear end. The new assembly is drum to drum complete. Before I install it, should I do anything about the internals of the differential while its out and readily accessible? Such as a rebuild kit or something similar? Never done a rear end swap so any and all help is appreciated. Thanks!

 

[Bonnewagon]

NO! Was it quiet? No leaks? If so, then just remove the carrier cover and inspect, change the lube and if posi, additive, replace cover and use a new cover gasket. Enjoy!

 

[MegaOlds]

Sounds good! Thanks Bonnewagon!

 

[pontiacgp]

since it's out of the car I would open it up to see what carrier it is and slide the axles out to check where the axles bearings ride on them and change the axles seals.

 

[darbysan]

You probably know this, but the driveshaft will likely need to be 1" shorter ( unless you got the driveshaft with the rear from the donor car). Good idea to check the seals and the bearing surfaces on the axles. Change the fluid at the same time. If it is posi, don't forget the posi additive. Use either the GM stuff, or get at least 2 tubes of the auto parts store stuff.

 

[Bonnewagon]

If he's never played with a rear (that doesn't sound right :shock: ) he doesn't know about the "C" clips holding the axles in. And bearings need to be pressed off/on, just to reach the seals, etc, etc. Then as long as I got it apart.........endless. I understand it's a whole lot easier to do these things with it out of the car, but if they don't need to be done why complicate things? And what if he doesn't like the 3:73's? Or it's a bad rear. THEN he will need to open it up for major surgery and then all that other stuff can be done. Like I said, if it's quiet, no leaks, leave it alone. Of course it may decide to leak later on, but he will now know how to drop the rear if need be. This is his first rear end swap and I think he should concentrate on getting that done correctly.

 

[MegaOlds]

I think I am going to leave it alone if it isn't making noises or leaking. Then I will drop it and open it up! Thanks for the replies