Gearbox noise - E240

[Valps]

I hope you learned folk can help me identify a noise.

I've just been up to London twice over the last two days. During the journeys I thought I heard a whine, presumably from the auto box. The noise is not very loud, but just there. Anyway when nearly home last night slowed for junction and the noise became a slight grinding noise just before a full stop. Pulled away again, no grind, but now back to a discernible whine. Grind returned as I stopped every time therereafter.

I appreciate it's really difficult to diagnose the problem without hearing it, but would value your opinions.

Incidentally the box changes up and down faultlessly, which seems like a novelty looking at some of the other posts.

Thanks in advance.

 

[nickmann]

Given that you hear a grind as you come to a stop it's possible that the noise is coming from the brakes. A quick visual check of the remaining pad material is in order and won't take more than a few seconds.

If not the brakes, then back to the transmission. If the whine appears speed-realted then you should check the propshaft or the diff. If the whine appears revs-related (ie the pitch changes when you change gear) then you are back at the gearbox, and at that point there is no subsitite for a hand-on diagnosis.

 

[Valps]

That gearbox/prop/axle noise

Phew this noise is a weird one. Definitely not brakes. Little sign of it when cold. Particularly grindy (is that a word?) on overrun when almost coming to a standstill. Accelerating from standstill little noise other than a slight whining. A bit like me really! In fact when moving forward at anything other than on overrun there is just that whine.

I've sourced a replacement 2nd hand box that's done 20K for £350 with a six month warranty. I'm not totally convinced it is the box but as it's probably the most costly of the three, and my good fortune being non existent ... I'm booked into my local indy next week but I would really value your ideas. Thanks.

 

[Parrot of Doom]

Could be a wheel bearing, but I'd say check your brakes. Perhaps a stone is caught somewhere in one of the calipers?

Try warming the car up, parking it on a hill in neutral, turning the engine off, and then rolling gently downhill to see if you can replicate the fault - although make sure that you don't hit anything on the way down, your brakes will need some force without the engine running!

 

[Valps]

Parrot, Thanks for your reply. It definitely isn't brakes. Wheel bearing is something I hadn't considered, but I will check it. Will rolling the car in neutral damage the box, or is it long distances that don't do it any good ?

 

[nickmann]

Rolling in neutral is best restricted to below 30mph, for less than 30 miles. Make sure all four wheels are on the ground, else disable ESP br removing fuse, or you will cook the rear brakes as they try and prevent what they see as a 30 mile long wheelspin.

It could still be the propshaft wheelbearing or the diff, based on what you have said so far. It's important to know if the whine changes pitch as the transmission changes gear.

 

[big x]

Rolling in neutral is best restricted to below 30mph, for less than 30 miles. Make sure all four wheels are on the ground, else disable ESP br removing fuse, or you will cook the rear brakes as they try and prevent what they see as a 30 mile long wheelspin.

It could still be the propshaft wheelbearing or the diff, based on what you have said so far. It's important to know if the whine changes pitch as the transmission changes gear.

Could be the torque convertor as well. Seems a bit drastic to change the box if it's still working.

adam

 

[Valps]

The plot thickens. In with my indy yesterday. He's stumped, but erring towards the diff. That's a new one on me. The noise is getting sightly louder. It's there in neutral forwards and backwards, probably sideways too! Anyway I'm off to Warrington on Monday. Should I throw something thick in the diff. Sensible answers only please

 

[Asif Kazani]

Have him check the center bearing on the driving shaft too. I have had a few diffs go out on my older model W126 300SD and I can tell you that unlike Japanese cars, thicker oil in the diffs do not make much difference in Mercedes'. However, when cold, thicker oil in the differential may help you make sure whether it is the differential or something else.

 

[GregE240]

My diff was a bit whiney (sp?) on my W210 240 when I had it.

Its the rear diff seals - the original ones weep a little oil and the diff can whine a little. Last service I had my man drop my diff oil out and replace it, causing the whine to go the same way as the old oil, well, pretty much.

New seals are around £10, bank on a few hours labour.

I doubt very much it is your gearbox.

Cheers,
Greg

 

[Valps]

Gearbox noise

Thanks to all of you for your advice. Car went on its 600 mile round trip to Warrington. No better no worse. Back in on Friday for further exploration. Definitely erring towards diff now. Hope it's just seals and fresh oil that's needed. I'll keep you 'posted'

 

[big will]

hello
i have the same noise probably on my 99 w210 240. as you i think the noise comes from the front of the drive train (gearbox) but i had it on the ramp with back wheel up an running on idle in gear and could hear the sound. checked all the components with a statusscope and the noise was the loudest (a lot louder then anywhere else) at the centre bearing of the propshaft. replaced the bearing without result although when back on the ramp the highest noise level is there. so now i am really getting a bit pissed off as i don't like noises that shouldn't be there and at the moment i am trying to locate a diff to see if that makes a change. hope you find the problem before i have bought a diff so i don't spend my money on the wrong thing.