1A Auto: Aftermarket Auto Parts

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Question Reply

Customer Question:

My differential looks like it is leaking on the right side.not at the gear housing but at the axle housing.Do I have to pull the axles and caulk it or is a easier way to stop it. 1990 chevy truck.

1A Auto Replies:

I haven't specifically done this job on a 90 Chevy truck, but I have definitely done the job a few times on other trucks, including my own.

Typically, you start by removing the wheels and drum brakes (or discs on newer trucks), and the differential cover. The axles are held into the center of the rear end with C-clips and the axles need to be pushed in towards the center to remove them. You need to remove a bolt and a small shaft from the center of the differential to allow the axles to be pushed in.

Once the axles are removed, you pop the leaky seals out with a flat screwdriver, and install the new ones. Caulk won't do it. If you think you need one seal, you might as well do both, because the other one will leak soon enough.

The differential cover is normally sealed with high temp differential RTV (Which is an acronym for "Room Temperature Vulcanizing" if you are curious.) Be sure to clean the surface of the housing and the cover really well to be sure it will seal properly.

Also use the correct fluid in your differential, it makes a big difference! If you have a limited slip you may also need additional additives.

I hope that helped!

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Welcome to 1A Auto! We are a family owned business, and for the last 50 years, we have been using the same high quality aftermarket replacement auto parts that we now offer for sale online.