8.8 Leaking pinion seal...

[Caver Dave]

I've got an 8.8 in the Mustang with 165k+ miles that's beginning to leak pretty badly from the pinion seal. It had a small leak (no measurable fluid loss, other than the "wet spot"), but has progressed over the past year. When I serviced it last year (7-8K ago), the seal was intact, but there seemed to be a very slight "wiggle" (axially) at the pinion flange. I hit it with an impact to make sure the nut wasn't grossly loose (wasn't), so topped it off.

While I know the seal can be changed, are the pinion (& carrier?) bearings pooched now due to the mileage? I suspect the pinion "egged" the seal and is causing the leak.

What should I expect?
Partial rebuild? (pinion bearings & seal + axle seals)
Complete rebuild? (all that + carrier bearings, etc)

I know I can find some decent (lower mileage/rebuilds) takeout 8.8's, but they're most likely going to be 3.55s, where my auto geared 8.8 is 3.27 and I like the few 100rpm difference at highway speed

 

[Jody Treadway]

It does sound like the pinion bearings are worn, causing the slop you mentioned. That tells me you need new pinion bearings.
In order to replace them, you have to remove the carrier. Go ahead and replace carrier bearings as well. Since all you need to do is replace bearings, there is really no reason this job will require anything more than a simple part replacement. Pinion depth won't change, backlash won't change, easy job really.

Call up Chase, get a overhaul kit, spend an afternoon elbow deep in 80/90 and brag on here how easy it was.

 

[zubz]

Worst part about the repair will be setting the pinion preload. Make sure you get it right or you will be going into the rear end sooner than you would like. Everything else will be a straigt swap over.

Buy a complete master install kit (from us preferably...) and it is a pretty easy job. You most likely will want to swap the carrier bearings as well because I would bet they probably have a good bit of wear on them.

Not worth buying a "good" takeout......you never know what you will actually get.

 

[Caver Dave]

Worst part about the repair will be setting the pinion preload. Make sure you get it right or you will be going into the rear end sooner than you would like. Everything else will be a straight swap over./QUOTE]

I respect your knowledge/experience and was hoping you'd jump in on this one brother! (sorry to bait you in like that )

Buy a complete master install kit (from us preferably...) and it is a pretty easy job. You most likely will want to swap the carrier bearings as well because I would bet they probably have a good bit of wear on them.

Assuming the "complete master install kit" comes with all the seals & bearings (+ new crush sleeve) to rebuild the pig?
In case I get pinched (for time & assuming it'd make it Durham ), any idea on labor charges for ECGS to perform the swap?

Not worth buying a "good" takeout......you never know what you will actually get.

There would be that...

 

[zubz]

I respect your knowledge/experience and was hoping you'd jump in on this one brother! (sorry to bait you in like that )
Assuming the "complete master install kit" comes with all the seals & bearings (+ new crush sleeve) to rebuild the pig?
In case I get pinched (for time & assuming it'd make it Durham ), any idea on labor charges for ECGS to perform the swap?
There would be that...

No problemo at all Caver.......I do build roughly 200 8.8s a year......lol

Yup, MIK comes with everything you need to do it. Only addition I would probably do would be wheel bearings and seals while you are in it. With as much metal as you probably have floating around in there, I would bet you might want to replace them while you are there and save yourself the hassle later.

Most likely you will have spun the side carrier shims so you will need to carefully measure the the area that is not spun and use the super shims included in the MIK to set the backlash.

MIK runs $85, wheel bearings and seals are $35 (total for pair of each) and if we did it in the shop you are probably looking at 3-4 hours ($225-300) if it is in the car labor and materials.

If it is a car you are driving alot on the road, I would set the pinion preload to the 12-14 in-lbs range. I think the book says 14-19 is spec but if it is seeing higher mileage we like to leave them a touch on the loose side.

Let me know if we can help.

Andy

 

[1997tj]

I would think the bearing preload is off now if the pinion nut was hit with an impact which could have caused premature bearing wear. That can also do damage to the ring and pinion if the pinion gear hits the ring gear with enough force so I would check those over when its apart.