[Drive25usac]

I have a '66 fastback, and, I have noticed a small amount of grease on the floor under the area of the rear u joint. I found the pinion seal appears to have a leak. Someone said the vent could be blocked, causing presure to build up when everything is hot, and forceing the grease out around the seal. I also had a leak in the left rear wheel, and replaced that seal.

Is the fitting for the vent hose pressed in, or is it threaded and screws in? It's a 8 inch rear end. The idea of just poking something in it to clean it out and maybe pushing gunk into the axel tube don't seem to be a good idea.

[Sick467]

I recently disassembled an 8" from a 65 or 66 and the vent fitting on the axle tube was threaded. It had a hex for a wrench so I just twisted and off she came. I can't speak for all the diffs out there but if yours has flats for a wrench, give it a nudge.

[RF Mustang]

My '66 (8") rear end is screwed in. had it off about a month ago replacing my rear flex hose for the brake line. It also holds your rear brake line flex hose /union on. ( at least it does on mine)

[Drive25usac]

Thanks for the info. I was hopeing it was a threaded fitting.