I have a 1981 Ford F100 Custom truck. I want to know how to grease the rear axle on it. Is there some sort of fitting that is used? or what?

Any input would be helpful.


Thanks,
Daryl S.

 

The axle is lubed by the oil in the diff. 80W90

 

and where is it found? The truck has a leaky seal and the oil leaks out from the rear brake area. The oil is coming from rear axle and I'm affraid to let it go dry for fear that the rear end may fall out before I can get the seal replaced.

Regards,
Daryl S.

 

On the right hand side of the axle, near where the driveshaft enters, there is a reinforcing web cast into the housing. Just above this web, you will feel a plug. A 3/8" drive extension fits this, and is used to remove it. Pull the plug out, and fill the axle with your favorite brand of 80w90 GL-5 gear lube until it comes back out the plug. Close it up, and you are good to go.

Jared

 

When you have the time, buy a new seal ~$5, differential cross-shaft lock bolt ~$3, 3qt of 80W90 ~$10, and a tube of silicone ~$5. Pull the rear cover & catch the oil that will dump out. Remove the lock bolt & then the cross-shaft, and push the axleshaft inboard. Then remove the C-clip from the end of the axleshaft inside the diff and slide the axle out. Pry out the seal, replace it, & reinstall everything. Let the silicone skin over for about 10 min before putting the cover back on.

You can find more detailed instructions in a Haynes manual.

 

Uh, it's an 81, so according to my book, it should have a 9".
You gave instructions for an 8.8

Jared

 

I've seen 8.8's as old as '81, and the 9 was used until '86.

OK If you have a ring of studs with nuts facing FORWARD, you have the Ford 9" rear end. Pull the wheel & brake drum and the 4 nuts that are accessible thru the hole in the hub flange. Then use a slide hammer to jerk the axle, seal, & bearing out of the axle tube. You'll have to take it to a machine shop to get the bearing pressed off & new parts installed, and then installation in the reverse.