the dealer replaced my clutch release bearing because when i am in neutral and i let off the clutch theres like a light light grinding humming sound and the dealer told me that replacing the clutch release bearing would cure it but it didnt and theyre puzzled they dont know what to do, so they told me to rebuild the tranny, not diagnosed just to see if it fixes the problem, one mech told me that replacing the bearing wouldnt do nothing because there was a permanent damage in there but i think he told me that because he didnt have the bearing in stock, anyways anybody have an idea of what it could be , haynes say that if theres a sound when depressing the clutch its the bearing but not when you let off the clutch in neutral


thanx in advance

1985 190e 2.3 16v euro

I think you first need to find another shop!!!

If there is a noise when the clutch is engaged (pedal up) it cannot be the release bearing because there is no load on it. If there is a noise when the clutch is depressed, then the release bearing may be a suspect.

Most manual transmissions are subject to a phenomenon called "gear rattle", which is a torsional vibration in the gear train, and it's nothing to worry about. Also, the clutch release fork can rattle at idle, which can make an annoying sound, but it won't hurt anything. My 190E 2.6 five-speed manual emits an annoying rattle when the air conditioning compressor is on and it's idling in neutral. It sounds like a couple of ball bearings in a vibrating coffee can. I pointed this out to the dealer during the warranty period and after some discussions I accepted that it's a "built in feature".

Run some tests to see when the noise occurs. Idle, with/without the compressor on? Increase the revs slightly with the compressor on and off. Does it go away, stay the same or get worse?

Another possibilty is the clutch gear bearing - the bearing at the front of the transmission or another bearing inside the box. A little noise might be normal, but if a mainshaft bearing or countershaft needles are spalling, the noise level will increase as miles are accumulated, and it will be much louder in the lower gears when power is tranmitted through the countershaft than fifth, which is direct drive. It's something you need to keep an "ear" on. If it gets worse, it might be time to overhaul the gearbox.

Duke

thanks for the reply it made me feel really good , anyways my clutch release bearing was wasted, i havo no a/c so thats not the problem, look at what happened, my clutch master cylinder was busted and when i depressed the clutch i can hear the sound slowing down until it came to a complete stop and after 15 seconds it started going again it sounds like it was accelerated until getting to same speed as the idle because when my cars idle sterts going up and down when cold i can hear the sound acclerating and decelerating at the same time as my idle, i already have a rebuilt engine so i guess it must be time to overhaul the engine but im short on cash, so how much should i worry about it??

very good info Duke

I've never owned a manual Mercedes but the noise you describe is familiar on other vehicles. It is unlikely that the release bearing would make a noise in the circumstances you describe, since this bearing is only spinning when you have the clutch depressed.

As Duke2.6 says, the bearing on the gearbox input shaft may be worn. I have run for tens of thousands of miles in vehicles with this problem, and never had a failure. I can't guarantee this will be true in your case of course, but so long as the gearbox is quite in normal running, I wouldn't worry.

__________________
Cheers, Neil

It can often be difficult to analyze problems based on verbal desciptions over the internet. It does sound like you may have an internal transmission problem. You could have it removed and overhauled or replaced, or you could wait and see what happens. The issue is: Will driving it until there is a hard failure cause consequential damage and cost more in the long run. That's the risk you have to evaluate versus the cost of overhauling or replacing the transmission now.

Duke

Djjeant, has anyone checked the other bearing? The one in the end of the crankshaft that accepts and supports the transmission input shaft after it passes through the clutch? Check the basics before listening to "rebuild the trans" and "rebuild the engine".

Don't overlook the possibility of the pilot bearing or input shaft bearing being the culprit. It would have only taken a few more minutes and a few more dollars to change the pilot bearing while they had the transmission out. I think you should find a different shop.

Good luck,

so i should have my input shaft bearing replaced, is it a big job? do they have it on fastlane? oh and the tranny is also leaking in the front and above the shift rods.

ok so i was sitting at a red light in neutral and i can hear the loud tranny and then i dont know why i let the car slide a little bit and the noise got quieter and im like WOW what happened? and i let it slide again for centimeters not much and it changes the pitch and i let it slide again and i hear the loudest it can get and i let it slide again and its like starting all over again until it comes to the liudest pitch and then all over again , just by letting the car slide in neutral very little by little, what can it be??????