maximabiz

Hey All,

Well, this weekend I'll be getting my rear main seal replaced. I have double checked, and it is definitly the rear main seal leaking (122K miles).

I bought the rear main seal and the halfmoon gaskets for the pan. What else do I need for this job. I have a friend mechanic who will do the job for me with my assistance, but I need to make sure I have all the correct parts and necessary supplies.

Do I need any kind of special tools for removal/install of the tranny? And how about tranny oil, how many qts will I need to replace once the tranny is put back? Is there any special kind of tranny fluid, should I get the OEM stuff or any good aftermarket fluid?

Any assistance is greatly appreciated.

Thanks
MaximaBiz

Scruit

This is a BIG job. About 15 hours

- Remove tranny (3-5h
- Remove belts at front of engine, and remove AC and AC mount
- Drop lower oil pan (steel)
- Drop upper oil pan (aluminum, looks like bottom half of engine)
- Remove both half-moon seals
- Remove rear main seal housing
- Remove all traces of permatex (the aluminum nicks easily, so don't go ape with the scraper)
- Install and torque ream main seal housing with permatex per manual
- install half-moons in upper pan and install upper pan with permatex (torque specs and sequence are critical)
- install lower pan with permatex
- install ac/mount/belts (good time for $30 in new belts)
- install tranny
- replace fluids



BEFORE you pull it apart, put UV dye in your oil and tranny, then check as you remove it for where it's leaking from. I pulled a tranny thinking it was a rear main leak and it was actually the 5spd front input seal that was leaking. Could only tekk via UV light/dye - otherwise I'd have spend hours swapping the rearmain only to find the leak persisting.

If you have an auto, it's easy to tell the difference between tranny and engine leak though.

maximabiz

Thanks for the great info Scruit,

Man, I didn't know the AC and belts had to be removed as well. Darn, I am really wondering if it is worth it to do all this?

I do have an auto, so pretty sure it is the rear main seal leaking oil. Can not think of anything else in that area.

Darn, Darn, what to do, what to do? Is there any online printable versoin of the shop manual detailing the steps, torque specs, etc... I am thinking my general mechanic probably does not have this info and will end up not reinstalling components improperly.

Thanks
MaximaBiz

Scruit

The big thing is that some mechanics will try to force the seal housing into place without dropping the upper oil pan. I simply wasn't able to do this while feeling confident that it would seal. It would go in skewed or the half-moon would pop out.

Some people say drop just that edge of the oil pan, but once you disturb the permatx you never know if it's gonna seal right again.

maximabiz

Hey Scruit,

Do you know how many qts of tranny fluid I will need to replace?

Thanks
MaximaBiz

Scruit

Dunno for the autobox. I have a 5spd. Sorry.

JAY25

iTrader: (38)

or you can drop the tranny, remove the clutch, flywheel, undo the 10mm bolts that hold the Rear main seal, remove the studs that hold the rear main seal put the half moon gasket under the seal use permagrey, seat the seal onto the rod that holds the flywheel and slide it in slowly. tadaaaaaa your done, I have done it like that

Scruit

Tried that. Didn't work for me. The new halfmoon seal was too tight a fit under the seal housing, and the only way to get it in place was to twist the seal into place, which kept letting hte spring fall off the seal.

After 3 hours of trying, I dropped the pad. Only an extra 2 hours of work once the tranny is off. And the result was I was much more confident on the repair.

After I pulled the pan I removed the rear main seal - the spring had fallen off again and I hadn't noticed it. If I had left it where I forced it into place with the pan still on then it would have leaked like a ****.

JAY25

iTrader: (38)

I understand what you are saying, sorry it didnt work out for you.

Scruit

The master Tech at Nissan suggested the same thing you did - so it's not totally bogus - it's just my experience was different. He also suggested pulling the two bolts from the upper oil pan either side fo the rear main seal so you can "flex the pan down" to make room for the seal. I figured doing that would damage the existing permatex seal so I chose not to do it.

JAY25

iTrader: (38)

I did it on a car and had no clue what was going on, after 4 hours of fighting with it, I found the short cut, by that time my friend had damaged the **** out of the seal, so it leaked slightly. How ever he redid it again but did not seat the spring properly, baaam brand new seal really bad leak so he did it againg for the 3rd time. Flexing the seal not a good idea.



Jaime

maximabiz

Hey Guys,

Thanks for all the great info. Does anyone have a spec sheet for the correct torque specificatoins? Or better yet, does anyone have, or know of a website that I can print out the instructions on how to remove/reinstall the components needed for this job?

I have great confidence in the tech doing the job, but if I had a set of instructions I would feel much better. At least that way the tech has something to go by incase he gets in trouble, plus he won't forget any steps if he had step by step instructions. My main concern is the torque specs, especially for the upper/lower oil pans like Scruit mentioned earlier. Guess bolt tightening sequence is crucial as well.

Keep the great info coming. REALLY APPRECIATE all the useful info. The more I learn, the easier I feel.

Geez, am I worrying too much about this? I'v never done a job like this, so kinda of anxious it goes smootly.

Thanks
MaximaBiz

JdawgX

15 hours??? Just curious as to why it took you so long. I can pull the 5 spd tranny in about an housr and reinstall it in the same time. I can't imagine that it would take 13 hours to do once the tranny is off. Myabe it does though??

Scruit

I can pull a 5spd in 1.5 hours and plug it back in in 2. I was quoting hours for someone who's not done the tranny drop before. That can esily be 5 hours from rolling the car in the garage to getting the tranny off, marking and labelling parts/nolts as he goes along.

Then an hour to pull the flywheel/clutch if it's a manual.

2-3 hours to remove the belts/AC/mounts, drop the lower pan, upper pan, clean up all traces of permatex and then put it all back together.

another hours to reassemble the clutch/flywheel components

Finally allow 5 hours to get the tranny back in.



If you've done this before the dropping the tranny and putting it back, plus swapping seal & cutch is a 5 hour job. But then if he'd done it before he wouldn't need to ask how to do it.


When I drop the tranny I take the Y and crossmember out also. And that passenger driveaxle intermediate carrier can take 30 mins alone to remove if the bearing is rustined solid to the mount.

JdawgX

Ahhh, your estimate makes more sense then. I don't drop the crossmember or the y-pipe to remove the tranny. I also don't remove the passenger side axel. Like I said though, your time seems to make much more sense now.

JAY25

iTrader: (38)

you guys remove the cross member, I dont even do that, thanks god for Gearwrenches

JdawgX

You missed where I said I DON'T drop the y or the crossmemeber. U-joints and extentions are your friend

Scruit

So explain how the tranny comes out with the crossmember and ypipe still in place... I had to tilt the engine down on the driver's side to clear the frame rail because of how far the input shaft fits into the pressure plate... How can you pull the tranny away from the engine wihtout tilting it? I even removed the mount from the tranny (not just unbolted it)

JdawgX

You pull the tranny out as far as you can and then tilt the rear most part (twords the firewall) up and you can pull it right out.

JAY25

iTrader: (38)

I dont know how many trannies you dropped but I never removed a crossmember. How ever I have removed the 4 bolts that hold it in place to tilt it far enough to stick a Gear wrench and or a small socket. Every car is a bit different as far as spacing goes. If you dont believe me there are two members that I have done their trannies and they were there to watch me do it Ramius and PRPmax. They will tell you I dont remove Ypipe and crossmembers, hell naaah thats just more work right there. I am going to try something new next time I drop a tranny I saw how the dealer does it and I now have a tranny jack so I can strap that sucker down.

JdawgX

I never even took the bolts that hold the crossmemeber up out. Never loosened them or anything. *shrug*