Engine rear main oil seal

[Pegjr]

How difficult is this to fix? Anyone have short cuts to make this as painless as possible?

[TxGR8White]

Depends on what you understand "difficult" to be.
I personally do not think it is difficult - last time I did this, I think it took about 3 -4 hours, but you have to know what you are doing and have all the proper tools. Even so, it is definitely NOT painless...

[olinjohnston]

This was one of the few things I entrusted to an independent shop.

If you have the time, the tools, and the space, do it yourself.

[legoman67]

it entails removing the transmission, torque converter, and flywheel.. once all that is done its easy...

[wokke]

Depends on what you understand "difficult" to be.
I personally do not think it is difficult - last time I did this, I think it took about 3 -4 hours, but you have to know what you are doing and have all the proper tools. Even so, it is definitely NOT painless...

Steffen, do you have some kind of F1 quick fix connections to your exhaust system and the tranny etc. ?
I doubt that I could do this job in 3 to 4 hours and I'm neither double left handed nor am I lacking the proper tools.
But I admit to have never done it yet with the engine installed in the car.
Only with the car removed from the engine and then it's a matter of minutes.

[TxGR8White]

I have a few extra rear cover plates (where the main seal is already installed). This job was done with both of the crazies at SPM. Greg and I have become pretty good at getting stuff done - plus I think after you do it several times, you know the sequence (that helps too).

[Pegjr]

Thx for the comments. What I was looking for is the experience you all have and if there is a particular sequence to make it more efficient than the obvious. Anything like the disassembly of the center consol and does the shifter need to be removed,etc. things like that so I can minimize the time the car is off the road. I am pretty handy at wrenching and have the necessary tools to do it. Lord knows I have done it before on my MG's,Alfas and Ferrari's.
BMW is a whole new thing for me and I look forward to the ownership of this car and learning the best ways to take are of it!

[legoman67]

shouldnt need to touch anything inside the car. straight forward transmission removal and reinstallation is 95% of the job... replacing the actual seal takes 5-10 min....

make sure you have about 3' worth of socket extensions .. makes the job MUCH easier

[TxGR8White]

- Remove Exhaust (forward half)
- Remove driveshaft
- Remove Transmission (be careful, torque converter!)
- Remove Rear Main Seal Back Plate, take to your workbench
- Remove main seal
- Install new rear main seal plate gasket
- Install Transmission
- Install Driveshaft
- Install Exhaust
- Change oil
- Drink Beer
- Twist key
- Drive off...

[Max Lumens]

Mission creep- You might as well get the gaskets for the water gallery crossover plate and the rear seal plate that are behind the flex plate. They're usually OK, but having them on hand could save you a wait for parts if not.

Upper pan gasket? Motor mounts? Etc....

[TxGR8White]

Mission creep:
You might as well get it over with now ---->

http://forums.bimmerforums.com/forum....php?t=1837814

[Pegjr]

Thanks for the advice. I have been out of town and just saw the comments. So I do not need to remove the shifter? Or just the knob before I drop the tranny? If that is it , then I am good to go! Thanks

[legoman67]

shifter is easily detached from the transmission from the bottom.

[e31bev]

My 840's having a rear main seal leak too but still rather slow of a leak. But I'm also looking into doing a manual swap sometime next year. Would it be wise for me to hold off on the seal just to save a bit of money on the manual swap? Does the severity of the leak get worse from hard driving? I'm thinking about just filling the trans with more fluid for now.

[olinjohnston]

My 840's having a rear main seal leak too but still rather slow of a leak. But I'm also looking into doing a manual swap sometime next year. Would it be wise for me to hold off on the seal just to save a bit of money on the manual swap? Does the severity of the leak get worse from hard driving? I'm thinking about just filling the trans with more fluid for now.

The rear main seal is on the back of the engine where it meets the transmission inside the bellhousing. The fluid leak is from the motor, NOT the transmission.

[hmfoster]

Any feelings about using Bars Stop Leak for a very minor leak.

[mjrgroup]

I didn't see anyone else mention it. But if you do this, drop the transission and change the rear main seal: do yourself a big favor and change the upper oil pan gasket too!

[e31bev]

Thanks Olin, shows you how much I know about cars. Well, better this way because now all I have to do is monitor the engine oil level.

[olinjohnston]

Any feelings about using Bars Stop Leak for a very minor leak.

If it was very minor, that would be even more of a reason not to use it IMO.

I wouldn't wanna pollute the whole engine over a small leak...I think that if you're committed to an 8-Series, a fluid leak (major or minor) should be repaired correctly or postponed until it can be.

[DanMarshall]

How difficult is this to fix? Anyone have short cuts to make this as painless as possible?

Had mine done while we were replacing the Upper Pan Gasket since we were in there anyway...
I would suggest that if you are in there anyway, you might consider doing the Upper Pan Gasket if it hasn't been done.
The first instruction in the manual for that repair is "Remove the transmission"...just a thought...

Oh, and forget the Bars Leak. No matter what they say on the can, it does not work on rotational seals.

Dan M.

[legoman67]

My 840's having a rear main seal leak too but still rather slow of a leak. But I'm also looking into doing a manual swap sometime next year. Would it be wise for me to hold off on the seal just to save a bit of money on the manual swap? Does the severity of the leak get worse from hard driving? I'm thinking about just filling the trans with more fluid for now.

are you leaking engine oil, or Transmission fluid? a bad rear main seal would leak engine oil. If you are leaking transmission fluid there are a number or things that could also cause that.

If your paying for labour, then for sure wait either way if its not too bad a leak. If it is indeed leaking transmission fluid and you plan to swap i see no point in repairing it. could cost $$$$.

[e31bev]

Thanks for all the expert advices. My mechanic confirmed that it was in fact engine oil and leaking very slowly.

[peezen]

I’m going to have to tackle this this spring/summer. I put my 8 to sleep this winter and it drained itself of all of its oil over 4-5 months!

I’ll have to do it at home, and have all of the tools necessary, but will have to have the car up on jack stands.

Has anyone done this at home on jack stands? I do have a tranny floor jack as well to cradle it, but clearance is always the issue.

Any advice or experiences would be valuable to hear.

Cheers!

[TxGR8White]

You will need some large jack stands to lift the car so there is at least 30” clear underneath. 6-ton Jack stands seem to be able to just do that.

[rjjablo]

I did my upper Oil Pan and transmission on Jackstands. Not the easiest, make sure you get it up high enough that you can maneuver under it with a creeper.

Debatable whether it is easier to just pull the motor and trans as a unit versus front suspension and transmission