6MT Transmission Selector Shaft Seal Leak?

[vincE92M3]

Brought my '11 6MT with 40,5xx miles into the dealer this morning for throttle actuator in bank 2 and they found a small oil leak with the tranmission selector shaft seal.

Did a quick search, but haven't seen any topics created on this for our cars. I did see that it was seen with E36 M3s however.

Has anyone else encoutered this? Just curious.

Luckily I am covered under extended warranty repairs.

[vincE92M3]

Guess nobody else has encountered this?

Seems to be an issue found on older cars perhaps.

[thekurgan]

What you have is pretty rare for any BMW.

[vincE92M3]

Interesting. I'm going to ask the service adviser more about it when I pick her up.

[GMWNashville]

Fairly common on all manual transmission bmw's

[kaiv]

^this. Although a bit surprising at only 40k

[vincE92M3]

Dealer costs to repair both throttle actuator bank 2 and the transmission selector shaft seal = $2800.

Thanks goodness for extended warranty.

[frankc]

I need to replace this seal on my e90 M3 as well as it is leaking.

Does anyone happen to know the diameter of the selector shaft, or have access to a MT where they can easily measure this? The reason I ask is I'm wondering if the tool in the link below would work for the BMW transmission, as the job looks much easier using this tool than prying the seal out with small screwdriver with the transmission still in the car.

The tool is for a GM transmission with a shaft that is 1/2 inch in diameter.

https://www.amazon.com/Transmission-.../dp/B00DJF7J9S

[pbonsalb]

I happen to have a GS6-53 from an E90 335i in my turbo E36 M3 on my lift right now and put calipers on the shaft and measured about 0.6 inches or 15 mm. The 135/335/535 version of the GS6-53 is the same trans as on E90M3 but with different bellhousing bolt pattern for the I6 and and 105mm rather than 110mm bolt pattern on the output flange to the driveshaft.

It was tight getting up in there with the caliper and my caliper is a cheap one, but based on what I measured, I not spend $30 on a tool designed to screw into the middle part of a seal with a 0.5” ID.

I did change the seal on this trans last year before installing it and it was no big deal to pop it out with a small screw driver. I had the trans off the car at the time. It would be tougher to do in my little E36 but the E90 has a bigger tunnel. However, there are console mounts on either side. Worst case, you might have to pull the driveshaft, which means pulling the midpipe.

Since this trans was in use in a variety of cars for over 10 years, I am sure someone has done it and posted about it. I’d google. Not so many E9xM3 DIYers.

[amrazM]

This is normal, if its weeping which it probably is I would put it off until you are removing the gearbox to do another task or dropping the complete exhaust. Access to this area is limited as it is in the transmission tunnel so you would have to remove the complete exhaust, remove heatshields and suspend the driveshaft then remove the shift carrier that attaches to the gearbox. If you reach this point there is a circlip that wraps the selector remove it and knock the pin out from inside of the selector then pull it out.

Ive used a pick to remove the old one, installing you can just use a socket to drive it back in.

Replace the selector rod joint after you remove it. beware it can be very difficult to remove the pin from the selector shaft with the tranny in, even when you tilt it back there is not much space.

[Scharbag]

Originally Posted by vincE92M3

Brought my '11 6MT with 40,5xx miles into the dealer this morning for throttle actuator in bank 2 and they found a small oil leak with the tranmission selector shaft seal.

Did a quick search, but haven't seen any topics created on this for our cars. I did see that it was seen with E36 M3s however.

Has anyone else encoutered this? Just curious.

Luckily I am covered under extended warranty repairs.

Mine leaked. Quite badly. Had a shop change it when they installed my short shifter. A crappy spot to work on but a pretty cheap part.

Cheers,

[frankc]

Thanks for all the replies. Sorry for the late response - I am subscribed to this thread, but for some reason I'm not getting emails about posts.

@pbonsalb, thanks for measuring this selector shaft. That GM tool looks like it would make the job so much easier when the gearbox is in the car, but unfortunately the diameter is a little too small.

I reviewed the procedure in various DIYs, and it looks very tight to remove the old seal with the gearbox in place. The car is on my lift right know with all the splash shields off (just replaced engine mounts and getting ready to do the rod bearings), so I may just disconnect the driveshaft tomorrow and see how much room I have to work with. I don't have a need to drop the gearbox anytime soon, so I'd prefer to take care of this now instead if it dripping and making a mess in that area.

[pbonsalb]

I have not removed my shifter yet but it is possible that If you remove the linkage you will have a more direct shot at pulling the seal through the hole from inside the car since the console tabs on the side of the trans won’t be in your way. Something to study.

[tlrid3r]

I've replaced this seal. I was actually loosing a bit of oil from there at track with some g force. I think worn engine mount cause this seal to fail because more strain on the seal from shifter offset. The Shifter is on a fixed location and excessive engine movement make it worse. It's weekend job. Just got to remove all underbody items to access shifter and install seal.

[frankc]

pbonsalb, thanks for the suggestion of possibly going at this from the top, but I removed the transmission
support crossmember and console, and that gave me pretty good access from the bottom.

I spent some time on this issue today. The picture below shows the selector shaft before I started working on it. The blue circle
shows a drip that is forming on the shaft.



After supporting the transmission and removing the transmission support pieces (and cleaning up the mess), you have pretty good
access the the shift linkage from the two sides:



With the transmission supports out of the way, I was able to:

• Remove the two clips holding the shifter linkage
• Pry out the shifter linkage bar (bushing were remarkably tight after 111K miles)
• Remove the lock ring holding the dowel pin in the coupling at the end of the selector shaft
• Remove the dowel pin
• Slide the coupling off the end of the selector shaft

The dowel pin was stuck in there, and it took about a dozen times of pushing it up, then back down to finally get it to move up enough
to slide the coupling off.

So here is where I am now, with the seal ready to come out:



I tested access to the seal with a small screwdriver, but with the Flex Disc in place, there is very little room up there. Normally the
procedure at this point would be to drop the exhaust, heat shields, and driveshaft to allow removal of the Flex Disc. But, I currently
only have a scissor lift which restricts access to the center of the chassis, so removing the exhaust is not an option at this point (I'm
getting a proper 2-Post lift in the shop that I'm building, but that won't be ready for a while).


Question - is there any way to remove the Flex Disc without dropping the driveshaft? I tried unbolting it from the output flange
and pushing it back, but without loosening the clamping sleeve near the center bearing, I didn't expect it to move (and it didn't).

At this point I'm going to wait until the new seal arrives on Tuesday to see how it is constructed, and then consider fabricating a tool
to help with removal. I'm also waiting, to see if anyone knows of any trick to remove the Flex Disc without dropping the driveshaft -
perhaps I'll post this question as a new topic.

If I succeed in getting this replaced, I post a proper DIY.

[frankc]

Originally Posted by tlrid3r

I've replaced this seal. Just got to remove all underbody items to access shifter and install seal.

When you say "underbody items" does this include the exhaust, & driveshaft? Or were you able to replace the seal without removing these?

Thanks

[tlrid3r]

Originally Posted by frankc

When you say "underbody items" does this include the exhaust, & driveshaft? Or were you able to replace the seal without removing these?

Thanks

Yeah I meant exhaust and driveshaft have to come out. Then remove the shifter and you will gain access to remove and press in new seal. I used a sock and dead blow hammer.

[frankc]

Originally Posted by tlrid3r

Yeah I meant exhaust and driveshaft have to come out. Then remove the shifter and you will gain access to remove and press in new seal. I used a sock and dead blow hammer.

Thanks for confirming. I'll probably just put it all back together for now and revisit it when I get the 2-Post lift.

[pbonsalb]

Life is better with a lift! And a 2 post can be cheap. My first lift was an Atlas BP8000 that I bought new for $1400 and picked up and installed myself including new electrical subpanel to bring 240 to the garage.

[M3BrianG]

Bringing up an old thread. Is this what is leaking on mine? Was switching out trans mounts when I noticed some brown goop on the inner part of transmission cover and then saw this ooze. Looks like it wraps around both sides.

[M3BrianG]

Originally Posted by M3BrianG

Bringing up an old thread. Is this what is leaking on mine? Was switching out trans mounts when I noticed some brown goop on the inner part of transmission cover and then saw this ooze. Looks like it wraps around both sides.

Nevermind it appears to be some sort of adhesive that PO put on to prevent shifter linkage from backing out or something.

[Latinskllz]

Interesting to see. I am having a shifter linkage issue I’m addressing and noticed the selector rod wet as well.

I’m gonna keep an eye on it.