This is topic Replacing diff housing--please help check my work in forum Spec Miata Garage at Spec Miata Community.

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Posted by Kyle Burkhardt (Member # 26745) on :
Just dropped the diff on my 99 and its sitting on my garage floor. The new housing is in the mail (thanks Drago!). Been doing some research, but before I get started, just want some direction.

As I understand it, once I remove the bolts around the housing, the only thing really holding the halves together is silicone. Once I pry apart, am I correct that all the "guts" will be retained in the front half? If that's the case, all I do is apply some RTV silicone, slap on the new housing and torque the bolts, right?

Posted by davew (Member # 214) on :
You are correct.

I would recomend replacing the axle seals while you are there.

After assembly, let the silicone dry overnite. Wet silicone gets everywhere. In your hair, on your arms, on your cloths......

Posted by Kyle Burkhardt (Member # 26745) on :
Thanks. For reinstallation, do I need to grease the axle splines (I just pulled them from the diff, they are still in the spindles). If so, what kind of grease?
Posted by Drago (Member # 1406) on :
Do change axle seals.. Also, be careful not to knock springs out of seals when installing axles.
Housing is on the way.
Posted by Keith in WA (Member # 16099) on :
I use anti-sieze for the splines. I don't know if it's a big deal if you maintain the car fairly regularly, but seeing how little corrosion requires measures to remove the axle from the hub that would put Discovery Channel "Big Jobs" episoses to shame, I'll take no chances.

I also replaced the circlips (those little springs that wrap around the axles where it pops into the diff). If they do get bent removing the axles, new clips makes the job much easier and at the end of the day they're essentially free. If you have a hell of a time getting the axles out of the diff, they're better than free.
Posted by W. Bonsell (Member # 14917) on :
Just took my rear hubs to the shop today to remove the old bearings and press in the new ones. Could not get the old half shaft out of the knuckle due to rust and just plain old age. Engineering shop used tons of force to get it to back out. Definitely using anti seize grease on re-assembly.

Got to believe the rolling resistance at the rear wheels was pretty poor...but everything coming together and almost finished with the Torsen install in my 1.6.