nfordhk

Hi,

My pinion seal is leaking, I received two quotes over the phone. One quote for 100 dollars for labor of the seal replacement. But I was told that I should rebuild the rear diff regardless which is quite a costly repair around 500 dollars.

Another shop told me a rebuild of the rear diff is not needed generally if the issue simply is, the seal is leaking. If there were strange noises or issues with the bearings then yes a rebuild would be needed. But generally speaking, no.

Thoughts?

tbear853

Over the years in VSP I had a couple cars ('94 Caprice and '98 Crown Vic) develop pinion seal leaks, both incidentally were near new when the leakage started and a new seal cured each for the duration of my use which was several years and 100,000 plus miles. Also had one ('06 Crown Vic) pooring lube it looked like from right rear axle seal the day I brought it home from headquarters. Local dealer replaced that seal as well, never an issue after that so I think those seals likely got nicked at or before installation.

Having said that, I noticed the other day that the pinion seal of our '08 GT is leaking a little and has slung some onto exhaust / floor pan. Car has only 24,000 miles so I'll likely replace that myself as it is more than just "seapage" .... and because it's easy ..... just takes some attention to detail and marking / measure before loosening pinion nut.

My '77 F-150 I've owned since 1986 stays wet from pinion flange back but when I check it, it's always near full .... so I top it off and keep on. Been that way for quite a few years, way over a decade anyway.

No sign of leakage on either T-Bird (the '92 has about 150,000 miles on it but the '95 has under 90,000) or Merc's (near 74,000 miles I think) 8.8 pinion flange areas?

70monte

There is no reason to rebuild the rear end just for a fluid leak. Now if you have some noises coming from the rear end, that is a different story. Anyway, the seal is a $100 repair so it makes more sense to try fixing that before going on to more expensive repairs.

tx_zstang

The main thing is that the repair is DONE RIGHT! Otherwise, you'll eventually need a rebuild.
Proper pinion nut preload procedures before and during pinion nut removal is CRITICAL. Any place using a 'torque it down with an impact' approach is not a place to go to, as that is not the proper procedure.
Look up online service procedures from Ford; that's an excellent reference on how to do it right.

And, you really should replace the pinion nut, too; there is sealer on the face of the nut that prevents leakage from the pinion splines. Re-using a nut can result in leakage through the pinion shaft itself (I've seen it happen).

The seal itself can be bought for $10 with sales tax or less. A new pinion nut can be $5 or less or $15, depending where you buy one.

robs

I had to replace mine. Easy $10 repair. Biggest thing is not to affect the preload on the crush sleeve... I simply marked the nut location, but wasn't really needed... as soon as you hit the crush sleeve, it's like hitting the wall on the torque needed..

Replacing the oil is expensive $75 for Mobil 1 and friction modifier...

ffk_pennywise

I had mine replaced a few months back for about $100. No big deal.