Hi Folks,

My 99 Tacoma with 125K miles appears to be having a rear axle oil seal leak from both sides. They started leaking about a month after I installed a lockrite in the rear. I replaced the diff breather, and they stopped leaking. About two weeks later, they started leaking again. The new breather seems to be fine.

I checked the tech articles in the Toyota maintenance section and found a good write-up on replacing the rear axle oil seal. The write-up mentioned replacing rear axle flange gasket with a new one. Unfortunately, I don't remember ever seeing a rear axle flange gasket when I removed the axles to install the lockrite. The write-up appeared to be of an older, pre-Tacoma truck, so I don't know if the Tacoma is supposed to have a rear axle flange gasket. Even if it is or not, could the lack of one cause a rear axle leak anyway?

Any ideas as to why both sides would leak, then stop leaking, and then start leaking again?

I have most of the parts available to replace both rear axle oil seals myself. But I'd hate to have to go through the trouble of replacing them just to have them leak again. I read one of the threads in the tech archives on a rear axle oil seal that repeatedly failed after several replacements. Although there is some good advice mentioned in that thread, there did not appear to be a conclusive remedy for fixing that problem. So any ideas would be appreciated on preventing repeated rear axle oil seal failures.

Thanks for any extra info and take care,

Hi Ed,

So the question is: How is replacing those seals now any different from when you had the axles out before? I don't know the answer, other than the seal would be new <img border="0" title="" alt="[Mad]" src="images/icons/mad.gif" />

I think there may have been a paper thin gasket, but so what? It doesn't seal anything, right? On second thought, we probably don't want it to seal. Seems like it would be better to have the leak show itself on the backing plate vs. inside the brake assembly.

I bought the new seals just in case we damaged one, but we never used them.

Our '00 4Runner leaked at 26,000 miles. My friend's '99 4Runner at 60,000. I've heard so many reports of 4Runners leaking, I'm thinking the cause has something to do with the Japanese vs. American assembly <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

What choice do we have but to replace them? You don't want the cast drum or the brake pads to get contaminated <img border="0" alt="[Mr.T]" title="" src="graemlins/mrt.gif" />

Hi Mark,

Thanks for the reply. Yeah, it seems like it's a common problem for the rear axle oil seal to leak on Toyota trucks/4Runners. I had a 92 4Runner where the same thing happened at around 140K miles.

I hear ya on the gear oil contaminating the rear brakes. When it first started leaking a month or two ago, I just sprayed brake fluid cleaner all over the rear brakes. Amazing how much of that gear oil washed off. Luckily, the brake drums did not appear scored or grooved from any potential excess heat that may have been caused by the leaking gear oil.

I guess I'll just have to replace the seals with the new ones and hope for the best. I'll also replace the rear wheel bearings just to be on the safe side since the truck already has 125K miles on it.

Take care,