Rear Main Seal (1 Viewer)

[kuuner]

Ok...a few months back I moaned about a front end rebuild and the cost the dealer was going to charge. You guys told me I could do it and I'll be damned if I didn't do it...correctly! Got some great new tools by the way.

Now I have a new dilema and don't want to get in over my head.

Problem: New found confidence in mechanics BUT...the only mechanical work I have ever done on a vehicle was the complete rebuild on my front end 85' FJ60. I have to have the rear main seal replaced due to the fact that I can't stand leaks.

Is this something I can do with just a brass diff and a 3lb. hammer (I am only half joking....)?

What is the difficulty level? What additional tools do I need other than the snap ring pliers, wrenches, jack etc.. that I used to rebuild the front end? Can I do it by myself or do I need help from a friend that can hold the truck up off the ground while I start unsrewing stuff? What else should I do while I am in there and finally...what the hell is a rear main seal?

 

[briguy44]

dude- if you want to feel like a man do it yourself. to do it, though, you'll have to drop the tranny, remove the flywheel, and clutch, and then take out the seal. it's not hard, just time consuming. you'll need sockets, a tranny jack, a screwdriver to get the rear main out. but yeah, you can do it. might as well put a new clutch in while you're in there if it isn't anywhere near new. if you have questions just post up.

 

[nuclearlemon]

i suggest the friend....makes it soooo much easier. i had two friends when i did mine.

 

[roscoFJ73]

Ok...a few months back I moaned about a front end rebuild and the cost the dealer was going to charge. You guys told me I could do it and I'll be damned if I didn't do it...correctly! Got some great new tools by the way.

Now I have a new dilema and don't want to get in over my head.

Problem: New found confidence in mechanics BUT...the only mechanical work I have ever done on a vehicle was the complete rebuild on my front end 85' FJ60. I have to have the rear main seal replaced due to the fact that I can't stand leaks.

Is this something I can do with just a brass diff and a 3lb. hammer (I am only half joking....)?

What is the difficulty level? What additional tools do I need other than the snap ring pliers, wrenches, jack etc.. that I used to rebuild the front end? Can I do it by myself or do I need help from a friend that can hold the truck up off the ground while I start unsrewing stuff? What else should I do while I am in there and finally...what the hell is a rear main seal?

Download a manual from http://www.birfield.com/ and go over it in your head so you understand the major points.

Its not complex,its just the weight of the gearbox/tcase.
Hire a gearbox lifter and some big stands with plenty of height.


A friend will be useful at the critical times when removing/replacing the gearbox.

 

[kuuner]

I'm married...so any chance to feel like a man I can get...I'll go for!

I think I'm gonna give it a try. I have a trailer so if I muck it up too bad...I take it to CTS in Connifer.

Wish me luck guys...there goes the weekend!

 

[swank60]

You know, you may want to do a little searching (under the truck) to make sure your rear-main is actually leaking. I thought mine was for a long time, but it's not.

First thing you need to do is pull the inspection pan - it's underneath between the engine and transmission - you really can't miss it. There may be oil all over it, and that may lead you to believe the rear main is leaking, but once you pull the cover, you can get a good look at your clutch, flywheel, etc. If it's covered in oil, it's the rear main. Another thing, if your clutch isn't slipping, it's not getting oil all over it, and the rear main, if leaking, will generally soak the clutch. Your truck is a later version than mine, so your clutch slave cyl automatically adjusts it's self to eliminate any slipage (I thought my rear-main was shot because I had some clutch slip, but it was an adjustment issue, coupled with a leaking oil pan gasket and lots of oil loss)

If you can clean all of that up, look in the clutch area, you'll have a better idea as to what is going on. - you'll need a rachet, a 10mm - maybe 12mm - socket and a 6" extension for this job...

Next thing you need to do is check the tightness of the bolts on your oil pan. The come loose - it's a common problem. I think you need a 12mm socket, rachet and an 8"+ extension to check on this. Sometimes you can tighten up the bolts, but it'll still leak - get a new gasket from CDan - or anyone who sells a ONE PIECE oil pan gasket. if it's a 3 piece, pass on it. You'll need to get a little RTV for that job, but it's well worth it.

I mention these things because you might be jumping the gun on a job that will require you to pull your transmission and t-case, replace the clutch and really keep you busy for a full weekend, maybe longer. You can also wind up with the wrong seal (just ask lowtide) and be down for a couple of more days waiting to get the right part...and all of that because you had a leaking oil pan gasket - which can really look more like a leaking rear-main than you might think.

The most valuable lesson I've learned while working on my truck is it requires a great deal of inspection before diagnosis or parts replacement. If you can learn to do these things, you'll save a lot of time and money.

Let us know how it works out! I hope it's not the rear main, for your sake - man, I'd hate to do that job.