W124 - Gearbox noisy = problem?

[Peter C1974]

Hi,

As this is my first post on this forum I will start by introducing myself. My name is Peter and a couple of weeks ago I bought a 1993 Mercedes W124 200TE, fitted with a manual gearbox. The car has covered 140k, has a FSH and the previous, elderly owner had the car for the past 9 years. In general, the car has been very well looked after.

I have noticed that the manual gearbox makes a "meshing" sound. The noise is not a whine and otherwise the 'box is in good condition, with no clonks and all gears engage smoothly.

The gearbox noise is not very loud but it is noticeable. The noise can be heard when I apply the throttle but the 'box is quiet on over run or at constant speeds.

The clutch release bearing is a little noisy (very slight) but the noise goes when the clutch pedal is depressed.

I suspect that the gearbox noise has something to do with the input shaft bearing, as the volume and sound are the same in each gear and increase with engine speed, not road speed. Or could it be the clutch bearing that is making the noise?

If it is the gearbox input shaft bearing that is noisy, would an oil change or top up improve matters?

Regards,

Peter

 

[television]

Hello Peter and welcome, the box has to come out to do the release bearing, and while it is out you could check the condition of the bearings on all of the shafts.

If you are the type of person who can do this,I can give you quit a bit of info

 

[Peter C1974]

Malcolm,

Thank you very much for a very prompt response!

The noise is nowhere near bad enough to warrant that sort of action. At best, I was proposing to top up / replace the gearbox oil but I thought I'd better check whether this is worth doing before getting mucky.

To be honest Malcolm, whilst I have the knowledge (I qualified as a road transport engineer before I became a chartered building surveyor!), I don't have the time or the facilities to carry out that sort of repair. Also, whilst I am not skint, I don't really want to spend £xxx on a clutch bearing repair until it really needs doing.

Over the years I have taken many lifts in German and Polish taxis, most of which are either W123 or W124 Mercs. The drivetrain on some of the higher mileage cars was so worn that you could barely hear the radio over the whine of the 'box and diff! When my car gets to that state, I will probably take further action.

Regarding my predicament, what do you reckon - is the gearbox noise related to the clutch bearing?

Regards,

Peter

 

[television]

Hi Peter, this to me sounds like the bearing on the lay shaft, as this is the only thing spinning when in N. This used to be a common problem on cars in years gone by.

I think that I would change the oil and add one of the additives that are on the market, they work quite well on diffs nothing to lose

 

[Peter C1974]

Thank you Malcolm. I'll have a go at topping up the oil tomorrow.

One more question! I've read in the Haynes manual that the gearbox filler plug is on the "right side of the gearbox". What it doesn't explain, is from which end of the car the reference is made! So, on a RHD car, is the plug on the driver's or passenger's side?

Peter

 

[power-steering]

Also check out using maybe slightly thicker grade of oil as an additive to your regular oil. I say this because using thinner oils reduces the vicosity (however it spelt) i.e spongyness (again however it spelt lol).

But only as an additive because of it's thickness it will take longer for it to move around the box but will give added protection and possibly quieten any crying from the box

Note: Always try a mix in the cup first to make sure they do mix well together and I always suggest if you're mixing like this, use different grades from same company i.e castrol.

It's not the best solution though, best is always to have the bearings swapped.

In regards to release bearing, have you had the master cylinder changed at all for the clutch? do you notice any play in the clutch pedal?.. it may be the clutch pedal is not pushing the release bearing hard enough against your pressure plates, there is adjustment for any play in the pedal behind it where the master cylinder bracket clamps on.

Goodluck.

 

[Peter C1974]

Hi power-steering.

Thanks for the advice regarding the additives. I'm off to GSF to get my bits, so hopefully they will all be of the same brand.

The clutch works absolutely fine. Nice low biting point, progressive release and no play in pedal!

Peter

 

[power-steering]

No probs.

You may not find a castrol additive for castrol gear oil but any additive would do. I meant if you wanted to use a thicker grade of oil AS an additive, then it should be same make as the primary gear oil you'll be using.

Good luck, let us know how you get on.

 

[Peter C1974]

power-steering, any idea on which side the gearbox filler plug is?

 

[television]

All the same LHD or RHD

http://www.detali.ru/cat/oem_mb2.as...07B&VIN=*&CT=GM&cat=07B&SID=26&SGR=530&SGN=02

 

[Peter C1974]

Driver side! Woo hoo! Thank you Malcolm.

 

[Peter C1974]

Update:

I jacked the front of the car up, slightly higher on the driver's side (the side where the gearbox filler plug is) and safely dropped it on axle stands.

The 14mm allen key socket fitted the filler plug ok but the plug was an absolute swine to remove. Considering I was under the car, there was little space to swing a decent sized lever. In the end, I pushed the wrench up using a length of wood and my hydraulic jack. Plug removed.

The gearbox oil level was a little below the plug level, but considering that the car was slightly tilted to one side, the level was probably spot on. There was no evidence of any leaks around the box.

I added a squirt of gearbox treatment solution (bought from Halfords, £6.99 for an 85ml tube, thick grey liquid, almost like a very fine paste) and topped up the 'box with 100ml of manual gearbox oil (slightly thicker than ATF I believe). Replacing the oil filler plug was a lot easier than removing it!

After washing my hands I took the car for a 30 mile motorway trip, which must have been far enough to allow the solution and new oil to mix with the old oil. To be honest, I don't think that my actions have improved matters, but that said, the gearbox noise was not that serious in the first place. At least I now know that my oil level is correct and the gearbox does not suffer any leaks.

Time will tell, but for the time being I've done my best!

Thank you all for your advice.

Peter C