The diagnosis on the Clutch is back... I need advice please
 

Hi guys,

The Clutch Doctor has diagnosed my 240D with 4-speed manual. Here are the symptoms:

1) Under hard acceleration from a standing start, the clutch makes some noise when engaging.
2) When accelerating, there is some vibration coming from the clutch.
3) Some noise comes from the clutch/transmission area.
4) The noise and vibration are 'sometimes' steady when the car is at speed. It seems to change based on the clutch engagement. (if I disengage and then re-engage the clutch, sometimes it goes away)

They told me that there is likely a finger broken off the pressure plate that is causing the slight vibration. They could not replicate the noise when engaging (probably because of a change in the weather) and the noise from the transmission/clutch area is a worn transmission input shaft bearing.

So, in order to fix all this, they said:
a) Need to change out the clutch
b) Need to pull the transmission apart and install a new input bearing.

They also said that neither item was keeping the car from running more-or-less normally, except that there IS a slight vibration and noise.

Surprisingly his advice was "Keep on driving it until something actually fails... you can drive a long time... maybe 50,000 miles until the bearing fails, and the vibration from the broken finger is not that bad."

I wanted to see what you guys think...

Sincerely,

Packman :)

I think the diagnosis of a broken finger is weak. Usually if there is a broken finger the clutch drags and makes it tough to get into first. Rattling in neutral is surprisingly loud in mb and bmw trannies without negative affect. Noise while engaging is likely the springs giving a bit....normal too.

I agree with his advice...drive it til something actually breaks!;)

What kind of noise is it making during engagement from a takeoff?

Input shaft bearings are always noisy on these transmissions. Always. They got loud early in in the car's life and stayed that way. Mine makes quite a bit of noise too.

Agreed, it doesn't sound like a broken finger.

FWIW, on my Jeep, the noise was a slight rattle in neutral, when I applied a bit of pedal, it went away. The local transmission place thought it was a weak finger. I didn't have anything done, as the guy mentioned it wasn't a big deal.

A while (can't remember how long) later the clutch was replaced.

If you want to check you could get one of them fancy bore-o-scopes (I think it was mach4 who bought a cheap one recently and reviewed it on the forum - but then again may be it was someone else - was it funola? I'm rambling - anyway) remove the slave cylinder and poke it through the hole...

...there's also a go no go gauge for clutch wear that can be utilised to help you decide whether you want to remove the gearbox or not...

Thanks for the responses guys. I realize that changing the clutch out is straightforward, and not hard to do.

My concern is more with the input shaft bearing on the transmission. I certainly have no experience with pulling a transmission apart (although I suspect it's not that big a deal), and getting the input bearing swapped out should be fairly simple for a competent shop. It's just that this is getting more complicated now. The clutch place won't do transmission repair, so they need to outsource it. I tend to have low-confidence in transmission places.

I found a used transmission locally, but it has 100K more miles than my transmission, so I'm not too keen on that.

I guess I'll call around to transmission shops.

Any other suggestions?

Thanks,

Packman

Wow. I just called a couple of local transmission shops. They all said the same thing: "We won't touch that transmission."

The reasons ranged from "It's too old" to "You need special tools from the 80s" to "We just don't work on anything from Mercedes". I called the biggest MB speciality shop in town and they said "No one will work on those. They require special tools from the 80s. I suggest you source a used transmission."

Wow. What do you guys suggest?

Packman

see post 2. Really.

I've had a lot of these cars and most have been sticks. The trannies are very tough and not easy to wear out.

Thank you for the thoughtful feedback. I truly appreciate it.

Here's some more detail: I have TWO 1983 240Ds. One has the vibration and noise problem, the other does not.

The reason why I am persisting in pursuing a 'fix' is simply that when I drive the 'defective' 240D and compare it to my other 240D that doesn't have the problems (vibration, noise), I find it really irritating when driving. For example, when I put it in gear and the engine is at around 3500-4000 RPM (I have a tachometer), I can feel the vibration and hear the noise quite plainly.

When I am running the car on the freeway, I am often cruising at 3600 RPM, especially when the speed limit is 70MPH. Although the car holds the speed just fine, I really dislike the vibration and noise that it is putting out.

I think I may have sourced a low-mileage (~180K) transmission, complete with bell housing and shifter from a Craigslist seller locally. I spoke to the mechanic who worked on the car before the engine failed and he said "I believe the transmission is fine. It doesn't grind in gears - so I think the synchos are fine, and it doesn't make any bearing noise that I can recall. It is not leaking either. I'd say it is fine."

My intent is to replace the clutch and the transmission and then use the car as my daily driver for the foreseeable future, giving my 2nd 240D to one of my kids or selling it.

I'm not a guy with a lot of money, but I am hoping that if I get this issue repaired, and if I can do all the other wrenching on the car, then it will be affordable for me to keep it.

Thoughts?

Packman

Still seems unlikely to be the clutch. Have you looked at your motor mounts and air cleaner mounts?

That is a good point. I looked at the motor mounts the other day and they look like they could be changed out. Weird thing is, the maintenance records say that they were changed just a couple of years ago.

I'll look more closely. Thanks as always.

Packman

Sometimes the motor mounts don't last very long. if fuel leaks on them is a bad thing. also some brands are considered inferior to the oe. mounts.

Agreed, the input bearing noise is nothing more than an annoyance. Just don't worry about it.

The vibration is a different issue though. That would worry me.

Thanks so much for the feedback.

I admit I'm a little confused here. If the input shaft bearing is making noise, then isn't that because the bearing is failing? If the bearing is failing, then couldn't it eventually disintegrate and cause even more damage? Isn't ignoring it asking for trouble? I don't understand.

I agree on the vibrations... it indicates to me that something rotating and spinning is out of balance, which, if ignored, could possibly become worse and cause additional damage.

I guess I've always held the notion to fix thing quickly after a symptom arises, or to pre-emptively fix an upcoming issue. This has always served me well.

Sincerely,

Packman

If it's that annoying I'll take it off your hands.