Transmission Input Shaft Seal Replacement Job - What Parts?

[racer2086]

Hey guys. It's actually my E39 with the leaking input shaft seal, but same transmission and engine as our cars.

I have a guy that'll do the job for me. I was going to order the parts, including the smart things to replace while in there.

And that's the point of my thread... Besides the shaft seal itself, what else is needed/should be bought?

I'll start the list:

1. Transmission input shaft seal
2. New Rear main seal
3. Rear coolant plate thing
4. ?

#12 in the diagram is the seal it appears. Do I need to get any of that other stuff around it?
https://www.realoem.com/bmw/enUS/sho...diagId=24_0720

diag_8h3.png

Edit: oops posted link and pic for the wrong transmission. This makes things a little more clear in terms of what is needed. I think I'll get #4 which is the shaft seals, #12 the input seal, and #11 and 13 since they're cheap and may need to be replaced with the input seal.

[purplecty]

Guibo flex joint?

https://www.oembimmerparts.com/BMW-F...1229065e38.htm

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[racer2086]

Guibo flex joint?

https://www.oembimmerparts.com/BMW-F...1229065e38.htm

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yes that is a good idea. In addition to the center support bearing adding that now

1. Transmission input shaft seal
2. New Rear main seal
3. Rear coolant plate thing
4. Guibo
5. Center support bearing
6. transmission mounts

[purplecty]

That should cover it i believe...

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[racer2086]

That should cover it i believe...

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Thanks. Anything that could break while doing this job that I should have on hand and return later if unneeded? I just want to be able to give him everything and get the car back asap.

[tjpike]

I added a couple things in there for you

1. Transmission input shaft seal
2. New Rear main seal (get the kit, it comes with the gasket and new bolts as well)
3. Rear coolant plate thing
4. Guibo
5. Center support bearing
6. transmission mounts
7. flex plate bolts (one time use with loctite pre applied)
8. upper oil pan gasket (in case it tears when the rear main seal is removed you can cut a section to replace it)
9. grease for the cv joint in the drive shaft
10. drive shaft cv gasket
11. might want to inspect/replace the shifter shaft seal while the trans is out of the car as well, doesnt hurt to have the output shaft seal as well.
12. exhaust gasket rings
13. exhaust nuts and bolts in case they are rusty or seized on there
14. transmission cooler line o-rings or crush washers as well

Hope this helps, I recently did this job on my car, so let me know if you have any questions or concerns.

[racer2086]

I had actually added a couple of those later ones as I was cruising FCP, but some of those I didn't think of at all. Thanks!

Since you recently did this job, did you find a cause for your leak? I'm curious why this young 540 (started leaking at 90k miles or less) would have this issue, while my 228k 740 has no issue. I'm hoping there isn't play in a bearing or something that stretches out the seal.

[tjpike]

I had actually added a couple of those later ones as I was cruising FCP, but some of those I didn't think of at all. Thanks!

Since you recently did this job, did you find a cause for your leak? I'm curious why this young 540 (started leaking at 90k miles or less) would have this issue, while my 228k 740 has no issue. I'm hoping there isn't play in a bearing or something that stretches out the seal.

No problem!!

So my case was a little different as I was replacing my torque converter due to the infamous shudder and lock up clutch failure, I decided to change everything in there since I already had everything out. With regard to your 540, how much fluid is it leaking? I agree that 90k is pretty low for the seal to fail. Although from experience with my car, when I pulled the torque converter out of the transmission, I was very surprised to see what looked like dried up transmission fluid that got thrown around in the bell housing. Hit it with some brake cleaner and it came right off. My point is this, my car right now has 93k miles and is/was not leaking transmission fluid, the seal could have been leaking slightly and fluid might have been constantly getting slung around in there, but not enough to drip out of the bell housing.

With regard to your concern about play in a bearing wearing out the seal, I don't believe that that is the case. The seal is mounted to the trans pump and meets the torque converter (rotates) where the input shaft goes in. So if you think about it, after years and years of rotational forces exerted on that rubber seal by the torque converter, it had to lose its tension at some point, hence developing a leak. Same thing ends up happening to the rear main seal.

[racer2086]

Yeah I guess, I was just surprised based on the youth of the car.

It's been leaving a drop over night (some nights no drop) probably for the last 1-2 years. The reason for this post was because I'm second out of the garage every day and I saw a dribble last time. Like enough to run a little on the floor. It hasn't done it since, but from what I've read, some people say the leak can suddenly let go. It may have been that the input shaft stopped on the seal just right that night, I don't know.

I got under and I can see in the lower hole where that rubber plug goes. The rubber plug won't even stay because the fluid causes it to blister and become very flexible. There is fluid in the bell housing behind the torque converter. The flywheel seems dry, so I figured that the transmission input seal was the culprit. I called Eriksson transmission in CT, and they said some 2000 years had defects in the transmission housing that would leak through some of those bolt holes. Guess I'll only know that when it comes out, but I can just see the bottom of the input shaft area and it is damp, so don't think that's the problem.

It's just frustrating to have such a large job to do on a low miles car that we rely on. I care way less when I can do it myself, but I don't have the equipment to get under the car and drop the transmission. This with the 540 and my crappy torque converter on my 740...not a fan of ZF.

[ConvGeorge]

The problem may actually be the lack of miles. Seals can wear out from mileage, but the can also get hard from non-use (lack of lubrication and flexing) and then leak. That's frequently an issue people discover when they buy low mileage cars that have been sitting around for a long period of time.

[racer2086]

Interesting point. It really started in CT with the cold weather, which probably exacerbated it getting hard and wearing. Makes me feel a little better that it's not some underlying issue that will cause it to leak again.

[georgebest]

What is a normal charge for labor for such work? At some point I have to do the same because of the torque converter shudder, though it went away for now after adding Dr. Tranny shudder fix. Likely wont last forever though.

[tjpike]

The problem may actually be the lack of miles. Seals can wear out from mileage, but the can also get hard from non-use (lack of lubrication and flexing) and then leak. That's frequently an issue people discover when they buy low mileage cars that have been sitting around for a long period of time.

Wouldn't seals going bad be attributed to constant heat cycles rather than just sitting? I doubt that rubber that has sat in a cool dry place for a long period of time would degrade beyond that of cars with higher mileage due to the constant temp cycles.

[acspecialists]

My father was a huge fan of snake oil to fix transmission. It softens the seals and orings that are old and crusty. If they crack of course nothing can be done.

[tjpike]

What is a normal charge for labor for such work? At some point I have to do the same because of the torque converter shudder, though it went away for now after adding Dr. Tranny shudder fix. Likely wont last forever though.

If you don't DIY, budget about $1500 including the torque converter and parts.

[georgebest]

I dont think i could DIY this without a lift, so no. Thanks.

[racer2086]

Guy near me roughly quoted me 600-700 for labor if I supplied the parts.

Should I replace the TC even though this car has no issues with it? I'm thinking no leave well enough alone...

Just parts alone for what we've talked about in this thread will be 300-500. I'm at $300 now without center support bearing, guibo, grease and gasket for CV.

[tjpike]

Guy near me roughly quoted me 600-700 for labor if I supplied the parts.

Should I replace the TC even though this car has no issues with it? I'm thinking no leave well enough alone...

Just parts alone for what we've talked about in this thread will be 300-500. I'm at $300 now without center support bearing, guibo, grease and gasket for CV.

That seems about right.

I'd say if you have the money to invest in a new/remanufactured torque converter, then why not. The stock torque converters almost always end up having problems especially when you near 100k ish. If you do want to replace it, I recommend Revmax, they're the ones I sourced a high stall converter from for my 750. Pretty reasonably priced too.

When it comes to transmission fluid, what brand are you using? I recommend you get the lifeguard 5 fluid. It's pricey, but will give you the piece of mind knowing that you have fluid that was designed especially for your transmission.

[racer2086]

I will probably go Lifeguard 5 in this car. I put Valvoline Maxlife in my 740 because the TC was already shuddering, and that's been fine so far. But the 540 is low miles, so we'll stick with the good stuff.

[purplecty]

I'll be using valvoline import which meets the LT71141 spec on my next change... Last one was Amsoil when i did the fluid and filter...

I will probably go Lifeguard 5 in this car. I put Valvoline Maxlife in my 740 because the TC was already shuddering, and that's been fine so far. But the 540 is low miles, so we'll stick with the good stuff.

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