I recently finished replacing the blown headgaskets on my 4runner and would LOVE to fix the leaky rear main seal. Replacing the headgaskets was a first for me, definitely the most advanced automotive repair I have ever performed. What I need to know is if replacing the rear main seal is more or less difficult than the HG job?

Is dropping the tranny and reinstalling it a difficult task? Are there a lot of intricacies involved in reassembly? I don't have access to a lift and I'm not going to remove the engine so i'd have no option but to crawl underneath for this job.

thoughts?

 

HG is definitely more involved. But I believe there's more "muscle" work involved in pulling the tranny without the engine.

 

the only real intricacie involved is lining up the input shaft from your tranny to the motor on reassembly, or the flexplate bolts and the TC if it's an auto. The actual gasket will be simple once you get to it.

You are basically looking at dropping the driveshafts, the exhaust(maybe), the starter, and then drop tranny/tcase, and then you can sit under it to replace the seal. The least fun is going to be had trying to get the top tranny to motor bolts and lining up the tranny for reentry.

Things to keep in mind -
- if its a 5speed now would be the time to do a clutch
- if its an auto, you are going to need a case of ATF

I removed the tranny/tcase/crossmember/ and both driveshafts as one unit and just slid it as far to the rear as I could, that worked for me - It all depends on how patient you are. A second hand is nice when your taking the tranny out and putting it back in. A prybar is also nice for seperating the motor/tranny initially.... what else - I use an impact with long extensions and swivels to get all the tranny to motor bolts out. The starter can be a pain sometimes.

Kat

 

Definately the rear main seal...first off your on your back...well i think enough has been said. but really though kat is spot on with the tranny job, ive replaced my tranny and my brothers we both have the auto a340h and both trucks are lifted, but i did the exact same thing she said. huge pain in the a$$. i would much rather be on my feet pulling heads off...it just makes more sense. yea im kinda bitter on the trannys

 

I just did the HG's on my '93 drove it around the block and then realized that I had to drop the tranny on top of it all. Mine being a 2WD (I just haul my tools or surfboard around in it.) didn't seem near as bad or involved as the HG. Yep the top bolts are a pain, but I got to them from above (Although I had the H2O by-pass off) with a short extension on ratchet that pivots for the slight angle and a breaker on that. An extra hand is good to have but I got by with a 2x8 attached to my floor jack with a metal strap to keep it from sliding. Still a bit wobbly side to side but manageable. If using a floor jack have something ready to rest tranny on once it's free. I set the front of it on a plastic milk crate leaving the rest on the jack and pushed it as far back as it'd go. That gave me plenty of room. GL

 

thank you all for your comments. after having spent parts of the past 16 weeks doing the HG job, the last thing i want to do is spend the next several weeks (at least) on my back. looks like i'll deal with the leak and make some calls to see who will do this job for the best price.