AMG Diff gone FUBAR

[MarkCL]

Fudge. Just dropped my C43 in to Oliver at PCS as I'd noticed what sounded like a transmission/diff whine over past few days - been getting steadily louder so decided I needed an expert pair of ears to see what was wrong. Turns out that my diff is screwed

First noticed it as a sort of drone/whine when off the gas from about 40mph slowing down. Did a hit and run on Olly's place on my way home today and after a brief diagnostic drive and then up on the ramp it's clear that the noise is definitely the diff - sounds even worse with no road noise to muffle it too :cry: Usually the AMG ones are supposed to be bullet proof so no idea what happened to this one in the past.

Only had three chioices - 2nd hand replacement (nope - no guarantee of quality etc, just doesn't sit well with me), rebuild (nope - unless it's done right you can end up with just as much of a problem) or new replacement from MB. Quaife don't do an aftermarket LSD one or I would have gone for that. The new AMG diff from MB is going to set me back around £1100 but at least it'll be guaranteed etc.

So - anyone with nasty diff noises, get it checked out. Worst case, the diff goes pop and locks both your rear wheels - at speed this can cause a bit of a brown trouser moment to say the least

Hey ho - no car now for a few days while the new part comes in More expense I could do without...

Cheers,
Mark

 

[television]

Bad luck Mark, but these thing do happen, diff re builders are scarce these day but a few left, I used to do it years ago and you had to blue the faces of the crown wheel and adjust the load bearing so that the pinion meshed exactly in the center. They were the days when engineering was a pleasure and good to learn.

MB have their own way of setting these things up as you cannot take the nose off complete with pinion and replace it.

A big problem is that if the car has been running a long time with the pinion bearing out of line due to a failed bearing, the chances of curing the whine are small, once the face of the teeth have worn on the crown wheel.

Always easy to tell, if it whines when pulling and quiet on the over run, the pinion bearing has failed

 

[bigasotonuk]

Hi,
Sorry to hear your tale of woe Mark, but £1100 does,nt seem too bad for an AMG diff, is that price including the VAT? do they want the old unit in exchange?
I do have a slight whining noise on my car you can only hear at speeds lower than 40, and I have made the assumption that it was my prop centre bearing, but now you have me worried that it could be my diff as mine has done a few more miles than yours.
Let us know how you get on,

 

[MarkCL]

Thanks to both Malcolm and Andy for the sympathy - much appreciated I understand about the rebuild issues, one of the main reasons why I was reluctant to go down that path to be honest.

As to the price, yes, £1100 for an AMG diff is more reasonable than I was expecting - a small plus to carry out of all this at least No idea if this includes VAT or not but I hope it does and Olly never said anything about taking my old unit back in p-ex - will have to check with him next week and see.

Andy, if I were you I'd get yours up on a ramp if it is making a noise and see where it's coming from - if it is the bearing then it should be easy to tell. For mine though there was really no doubt where the noise was coming from, even had some nasty metallic munchy sounds going on when you were right under it and could hear everything :Oops:

I'll keep you informed as to the final costs etc - fingers crossed this will be the last big bill for a while, I'm still trying to save up enough to get the respray stuff done :neutral:

Cheers,
Mark

 

[bigasotonuk]

Good luck, i,ll be interested to know how you get on.

 

[whitenemesis]

OK not an AMG but still a diff

MB spotted oil seepage from my diff during an MOT and advised replacing the oil seals. They seemed quite concerned this be done sooner rather than later. Oil level was checked and was acceptable, they topped up and cleaned up. Seals being replaced next saturday (FOC under Service+)

Perhaps the occasional grovel under the car, just to check for early signs of failure, is well advised!

 

[Blobcat]

OK not an AMG but still a diff

MB spotted oil seepage from my diff during an MOT and advised replacing the oil seals. They seemed quite concerned this be done sooner rather than later. Oil level was checked and was acceptable, they topped up and cleaned up. Seals being replaced next saturday (FOC under Service+)

Perhaps the occasional grovel under the car, just to check for early signs of failure, is well advised!

My W210 used to leak oil from the seals because the breather became blocked. I understand it is fairly common for the breather to block although the amount of oil that is lost is very small. I had the seals and the breather changed.

 

[vijilants]

Re leaking oil selas, same with mine....common problem. Had it recently done.

 

[MarkCL]

Well I have it back again Amazingly quick turnaround by Olly and Jack, which is perfect as I need the car for work again from tomorrow. All seems fine now thankfully - no more nasty whine or munchy sounds from the back anymore All in it came in just under £1500 which considering £1121 of that was the diff and some of the rest was VAT I really can't complain. Excellent job by PCS as usual and at least I have a working car again to come to the meet on the 16th now too

I'll get the diff oil changed out now at about 1000 miles just to be sure any bedding in metal filings get removed from - oddly enough it was one of the first things done when I bought a new beemer before, but apparently not necessary on the Merc. Still, for my own peace of mind I'll get it done anyway just to be sure Another big thank you to Oliver and Jack at PCS - not sure what I'd do without those guys...

Cheers,
Mark

 

[bigasotonuk]

Hi,
Glad you got it sorted Mark, did you have any of the mounting bushes replaced?
Don,t blame you regarding the oil change on the diff, I,m gonna get my diff oil changed ASAP, as I have no record of it ever being done, I went to Ollies on Friday regarding some work that hes doing for me at the GTG next week and I described to him my symptoms and noise on my 43 and I,m pleased to say he agreed with my diagnosis regarding the Propshaft centre bearing.
Are you going to Ollies GTG on the 16th?

 

[MarkCL]

Hi Andy - no bushes changed no, Oliver never said they needed it so I didn't even think about them I have to admit. Bugg3r. Really should have had those done at the same time. Maybe he can do them without too much aggro when the diff oil gets changed in a thousand miles, we'll see.

As to the GTG, yup, should be coming to that one yes Looking forward to it - hope the weather improves again by then, rain forecast for most of this week I heard?

Cheers,
Mark