Sadly..This is a big job and the engine and tranny must be dropped and separated....and all parts are quite expensive and it's time consuming. If they 'do the clutch' ,..they might want to turn the flywheel too. It's going to '$add up$' ,..if you let them do it all..

....but 9 hours does seem a lot for a well equipped garage..

Strange that the sound goes away when the clutch is depressed,..I would have thought that loading the thrust bearing(ie:depressed)... would bring the sound/grinding on.
We have experts here that will add to this,..I hope..

 

Yes, release bearings sometimes make a sound when not under load. Usually when they're starting to go. Then later they become really noisy under load.

Get a couple more quotes from reputable companies, and weigh whether it's worth it, considering you may have trouble selling the car with the noise or may get less money for it.

edit: please update profile (see example to the left).

 

I took the car to two mechanics today who both said the problem is the gearbox. Sounds even more expensive!!!

 

How many km on the car? Are you the original owner? Any abusive or novice drivers using the car?

Not common to hear problems regarding the manual gearbox. Also, this is the 5 speed, correct?

 

Not sure on previous owners as I only just got the car but it has only done 75,000 miles. It's a five speed manual.

 

Philbrian, please update your profile

 

Paulo and Stefan...Would you recommend "bananas" as a last resort in philbrian's case...??
It did work well in the old days...

 

^ Never heard of that one You're one of a kind, DEVOURS! I take it this was some sort of band aid fix for putting in the tranny oil? Just like putting eggs in the coolant system when you have a rad leak? Or does eating bananas fix the tranny?

Seriously, I'd drain the fluid NOW and refill the right quantity of the approved oil from M-B. Worth a try cuz that's a cheap and easy fix before going further. If it's doing it in gear, it's not the synchros, so either the bearings or gears meching improperly or something else I'm missing. Let us know please...

 

If we put this "banana" solution in the BW "General Forum", we would get some interesting responses. I'm hoping that someone here goes back to the 60's and 70's...

I do know mechanics with a racing background who actually put bananas in their manual tranny to hide failing sounds.

I'm not saying that's what to do. I just thought that some "mechanically inclined enthusiasts' here might have heard of this "trick".. This was done long before synthetics were around though.
Wonder what happened during the winter freeze-up... ..Frozen bananas...


Good advise from Paulo here,...maybe the oil change might make a difference.. Lets hope so...

 

I found some posts about Lucas Heavy Duty Oil Stabiliser being a good fix for noisy gearboxes on other cars. Do you guys think try this or stick to the recommended Merc gearbox oil?

If changing the gearbox oil doesn't work, I would be looking at getting a used gearbox from ebay or a breakers. Do you know if other gearboxes will fit my B170 Manual? Eg a gearbox from an A Class?

 

I've been told to only use MB recommended fluids for the MB mechanicals like the diffies or tranny.

The major pieces are all interchangeable from the A and the B Class. Most part #'s on my B start with the letter A showing that it's also an A part too. The part # will be on the tranny somewhere.

 

I know exactly what the problem is as I literally had mine fixed today.

I have a b150 manual and had the same symptoms and problems with the noise etc.

It is the gearbox, but to be more precise its the gearbox bearing.

There is 3 altogether however usually the main one on the centre spline is the cause.

I was quoted ridiculous prices as many mentioned you have to drop the whole engine etc etc.

However after taking mine to a fantastic garage in essex local to me the guy managed to change the main bearing and keep the gearbox in position!

Am over the moon with it and the noise has completely gone.

Took 1 day to fix and £500.

Was quoted around the £1000 mark from other garages and even £2800 from mb.

 

It is the gearbox, but to be more precise its the gearbox bearing.

There is 3 altogether however usually the main one on the centre spline is the cause.

However after taking mine to a fantastic garage in essex local to me the guy managed to change the main bearing and keep the gearbox in position!

Am over the moon with it and the noise has completely gone.

Took 1 day to fix and £500.

I'd be over the moon also and at a fantastic price too.


Could you tell us how the repair was done with the tranny still in place??..and could you give us more details on this repair.?

 

To be honest mate I couldn't tell you exactly how the job was done. He told me it was some serious key hole surgery. I will happily pass on the details of garage but I'm guessing it wouldn't be any use to u as your in Canada.

But seriously up until yesterday I was in exactly the same boat. I only have had the car 4 monthes when this grinding noise began.

Many garages said the clutch or thrust bearing.

More garages said the gearbox which is correct however they was all going to remove everything and recondition the whole gearbox and stated £1000ish.

The problem is no one could ever say for sure what the problem was.

You need to find a very good transmission specialist.

Don't bother with everyday mechanics or even MB as all they will do is take the gearbox out and sub it out to a specialist themselves while wacking the price up.

 

So I mixed some Lucas Heavy Duty Stabilizing Oil (25%) with MB gearbox oil but it hasn't made any difference as I still have a noisy gearbox bearing. Bondy2013, could you tell me the name of the garage? I might take my car down to him.

 

Hi yeah sure it's Thames transmissions on Canvey Island. Just mention John advise me to come down whose b class he fixed last week.