Bad Pinion Seal

The TR3A rearend has a badly leaking pinion seal.

I pulled the diff cover last night, and the gears all look good. I suspect that the outer pinion bearing may be bad too, from contamination, because it feels "sandy" when I spin the pinion.

I suspect that the seal and outer bearing are not pressed onto the pinion shaft (how could they be?).

From the looks of it, I need to pull the shafts, remove the carrier, remove the pinion from the housing, pull the outer seal, bearing and shims from the housing, and then replace those damaged components and reassemble.

I have gauges for checking the backlash and an inch pound torque wrench for checking the pinion resistence that I purchased when I was rebuilding the axle on my Jeep. I also have a slide hammer. Are there any other tools I need to do this job?

Am I crazy for even attempting this?

Yeah, you need a case spreader! Churchill tool # S101. It spreads the diff case enough to get the differential assembly out of the ...case. I read here that it isn't neccessary, but I've never done the job, so I don't know. The service manual says you need the tool to get the diff out. I'm sure someone who has done this without the spreader will chime in. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

People who should know have written that the spreader is not necessary : by prying on both sides at once you can force the carrier out without spreading. Haven't tried it myself though.

Or, it looks easy enough to fab a spreader, from some drilled flat iron and a couple of big turnbuckles all from HD.

The book talks about some other tools needed to select shims, but hopefully you can get away with keeping the same thickness for all the shims (although you may still need to replace any that get damaged as you disassemble the unit).

If the front pinion bearing is bad, there's a good chance the rear one needs to be replaced as well; which requires some more tools to remove and install the inner cone on the pinion shaft. But an ordinary bearing puller (eg HF) should do.

I pulled two carriers and neither required a spreader to remove or intall.

Make sure that you keep the shim pack for the pinion intact for reassembly.

If you're lucky, you may be able to clean out the grit but close inspection is required to be certain.

I think I can fab up a spreader if I need one. I'll give it a shot tonight and let you know for sure.