Hello everyone,

I recently got my hands on a 1999 4runner SR5 with 230k on it. There is an oil leak which I believe to be the valve cover gaskets. I also noticed there is a small leak coming from the input shaft/bearing area on the transfer case. Is this an easy fix, or does the case have to be dropped and split?

Any tips and tricks? Maintenance items that should be done? Timing was recently done so I know that's good.

I am comfortable working on vehicles, but this is my first Toyota so any advice is welcomed.

 

I don't know 4Runners quite as well, but is the engine the 3.4? Valve cover leaks are common after a few hundred thousand miles. I replaced mine at ~190,000, and now at 310,000 they need it again. There's a writeup either on this forum or another Toyota forum...try google and you'll probably find it. There are a couple other things it's good to replace while you're in there, and I remember the wiring harness being a bit of a pain, mostly because by now it's really brittle and can break easily.

A lot of this stuff I did so long ago my memory of it isn't so fresh...It's possible that if it's an input/output shaft seal that's leaking, then all you need to do is disconnect the driveshaft, remove the staked nut, and replace the seal. You'll need a new seal and nut. Very specific torque method, but not hard. Just needs to be done a certain way. There are plenty of forum and video tutorials for all this stuff, along with the repair manual.

This guy posts a ton of great repair videos. They're by far the longest ones you'll find, which is both a blessing and a curse, but he's thorough and the videos are great.

 

The bolts holding the valve covers on sit on bit rubber washers, they shrink and flatten with time. You might try gently (GENTLY! It's easy to overtighten and break the valve cover) tightening them. It might work for a while. I think I got another year out of mine that way, then when it started seeping again I spent the time to replace the gaskets. USE OEM, my wife used a non-OEM head gasket kit during her HG job and they started leaking pretty quickly.. She redid it with OEM, I did mine with OEM, and they've been dry for a decent amount of time since then.

 

And put up a pic of what's going on with the transfer case. Is oil leaking out from the junction between the trans and the transfer case? I guess if it's an automatic trans, there's no doubt wh8ich of the two the oil is coming from.

All of the seals on the transfer case can be replaced without disassembling it, but a leak on the input would require taking it off the trans. But the seal is pressed into an end plate/cap bolted to the transfer case housing. No need to remove that either, just hook the old seal out and drive a new one in.