This weekend a friend and myself pulled my 3rd members out of my Toyota and replaced them with 5.29 gears and a Detroit in the front and full spool in the rear. After getting everything put back together, brakes bled, and on the road, I drove it home from the cities to Mankato. These were both used gears and had already been broken in but I still drove 55ish mph (or what I think was 55 as I dont know how far off the speedo is now again) and took it easy on the gears. When I got home I noticed that there was oil that was seeping out of where the axle bolts to the housing in the rear and also that oil had been flung above where the pinion is located.

I talked to the guy I bought the third from (Local guy) and he said he never had any leaks with that diff. Could the pinion seal have been tweaked or rotted as it hadnt been used for about a year from when it was pulled from his truck? I am also thinking it might be that the axle breather could be plugged, but then thinking back to my stock gears they never leaked at all. I felt the housing as well when i noticed it and it warm, but no where near what i would consider "hot". Ive never felt a diff after a 100ish mile trip before so i dont know what I should be feeling for warmth either.

If it is the pinion seal, would that be somthing a shade-tree mechanic could do himself (me) or would i be best off having a professional (pay for it) do it? I have plans to put on different breathers but want to make sure the gears will be alright.

Thanks!!

~Eric

First, did you use synthetic gear oil?

Pinion seal is pretty easy to replace:
- http://www.4crawler.com/4x4/CheapTricks/PinionSeal/index.html

Nope, just used regulart old 80-90 as I expect to be changing it fairly frequently from wheeling.

I changed out my breathers yesterday and even after sitting over night the rear breather made a "Whish" sound relieving some pressure in it. Chances are good that's what was wrong with the rear. Time will only tell with the front one as that one is a much older third as well.

Thanks for the replies and that great link to change out the seal myself!

Just curious, would synthetic gear oil make the problem worse or better? Thanks ZUK!

From where the 4 nuts attach the backing plate??
If from here, your axle seals are probably toast. It's a good idea to replace those whenever you pull an axle shaft from the rear. Especially if your not careful while removing the axle's to swap the diff.

With used old seals, synthetic will get by where the regular gear oil won't. When you said the axle seal was leaking, that's what made me think of the oil. But it looks like you found the prob <img src="/forums/images/graemlins/kewl.gif" alt="" />