9" Pinion Carrier Flange Leaking

[Blackmutt]

I've got a 9" ford rear end and the pinion carrier is leaking--Not the main flange seal but the 5 bolt flange where the shims are. What's the best way to fix it and can it be done without removing the third member from the truck?

[sickrick]

Check and see if the bolts are loose. There is no gasket there so it should only leak if it is loose.

Yes you can unbolt it without removing the entire third member.

[Blackmutt]

All 5 bolts are very tight. Would it work to remove the flange, put on a thin layer of silicone and bolt it back together?

[loufish]

The pinion carrier can be removed on the truck, sounds like the "O"-ring on the carrier is leaking. Remove the carrier and not only replace the "O"-ring, but do a check to insure the are no nicks to cut the new ring...Don't forget to put a little lube on the ring for smooth installation.

[Fab4fun]

Assuming all fasteners are tight, and nothing is cracked, there are 3 places you can leak oil in the pinion support area.

The first is around the outside diameter of the support, ( your problem area) which has an o-ring, (and they can get hard and even get a flat spot on them and shrink up) around the OD which seals to the case. Remove the pinion support bolts and examine it first. If you believe that is the problem area, then replace with a new o-ring that has a light coat of oil on it.

Second is around the seal of coarse. Seals wear out, yokes wear grooves in them which cause improper sealing.

Third, is the leaking of oil between the splines of the pinion shaft and the yoke. This can be caused by poor tolerances, or both parts being on the extreme opposites of tolerance. The oil leaks past the the interference fit between the male and female splines, and then runs out around the pinion nut.

Torque those pinion support bolts to 25-30 lb's after you put lock tight on them.