CV boot slipped off...mechanic at fault?

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MB-BTurbo

Active Member
Joined
Nov 13, 2011
Messages
993
Car
B200 Turbo
I have just noticed that the small ring clip circled below (not actual photo) has separated from the rubber boot.I had the whole cv joint replaced in August and noticed a 'crackling' noise straight away, as though it was being over stretched. Thought I would see how it goes in case the rubber was stiff. After a month the noise stopped and I thought nothing more of it. Would I be right in thinking that this was not put on correctly or have I been unlucky?

I need to take it back to the mechanic and need to know the best approach. On a side not would there have been an issue of grease starvation (from it escaping) or would centrifugal forces keep it away from that area?

 
Without seeing the job, this is a difficult call. However, if it was the correct boot and had been fitted correctly, I think it's fair to say that it wouldn't have come off so soon. I also wonder if your mechanic used new clips - if he tried to re-clip the old one it is no surprise that it has come adrift. However, I've seen repair kits that use plastic tie wraps on CV joints and are perfectly satisfactory.

I also wonder if genuine MB parts were used? I have a hunch that MB only sell complete drive shafts for the A and B Classes, but could be wrong.

As far as the grease is concerned, as the boot was new, it would still be protecting the joint and unlikely to have lost too much, if any, grease. You would see evidence of grease on the underside if any had been thrown out, however.

NOt sure if this is any help to you, but for me, if the job was done properly, it wouldn't have failed so soon.

Ernie
 
Thanks, very helpful. No it was a third party, but respectable company, cv joint. You are right Mercedes do not offer a separate cv joint instead trying to charge £100s for a complete shaft. Compared to £60 for the cv joint I paid through euro car parts it was a no brained. I guess I need to bare this in mind and see what the mechanics have to say. I will try and get a picture of the actual joint tomorrow.

There is some grease that has clearly escaped, how much I have no idea. Hopefully it can be repacked.
 
The gresse would not have escaped, but it could get contaminated with moisture and dust if the gap was significant.

In the olden days I used cable ties, they seem to last longer and do not corrode, but they would have to be of good quality or they become brittle with time.
 
Here is the offending boot. Not overly clear but you came make out the clip separate to the boot.

 
I think that joint will probably be OK if repacked with grease. I had a Mk1 Mondeo that I ran for weeks with a badly split CV gaiter and there was grease flung all over the place. I repacked it with fresh grease and put a new gaiter on it and went on without problems for a couple more years before I sold the car on.

I'd be satisfied if your mechanic just offers to fit a new clip and repack the grease.
 
Thanks guys for your input with this. Will get it done next week, might even look at doing it myself as it seems fairly straight forward.
 
Make sure you degrease the shaft and inside the boot (where the clip fits) or it will never stay in place.
 
To update. I took it back to the mechanic in the end. They sorted it without charge. Can't say fairer than that and gives me a lot of confidence in using them again.
 
THREAD UPDATE
The CV joint started clicking at the end of December. I took it back to the mechanic who fitted it. He suggested that it might be a driveshaft at approx £800 and was uninterested in the idea that it could have been caused by the boot clip slipping off. As I hadn't got that sort of spare cash I've been getting lifts until common sense came to me and I went to get a second opinion. They confirmed that it was the CV joint. As it was only £130 I went ahead and had it fixed. The new CV joint has only been on for 8 days and is now clicking worse than before. This time there is no obvious reason. The new mechanic was a little reluctant to repair under warranty suggesting that it might be the cars fault that it keeps going wrong but he accepted it back and is booked in tomorrow.

Now praying that this fixes it as Mercedes 'dont sell CV joints'! Is there any reason for a CV joint to fail so quickly?
 
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You can buy cv jiont ends from various companys just make sure you get a new snap ring as when you get the old cv jiont off it bends the retaining ring and its a right pig to put back toghter. For parts like this a euro car parts type supplier could really save yourselves alot of money compared to dealer prices.
 
Sounds like there is something wrong.
Are you sure its the outer cv joint not the inner one that's clicking?
 
From what I and two other mechanics can hear, we are pretty sure, also the new noise only started with the new CV joint fitted.

The first joint failed because of a split boot, the second I suspect was because I was driving around for 6 weeks with the clip having come off the boot (that was a GKN from eurocarparts) and now this one. If something was wrong, what could it be that is causing them to fail?

Not sure if it makes much difference but the noise is slightly different each time. The first time the CV failed it became progressively worse. It started off clicking at full lock, then eventually mid lock. The GKN fixed that but after the boot clip fell off it started clickig quietly, gettin progressively louder as time went on. This sounded on full lock whether the accelerated was pressed or not. This time it sounds loud but only on full lock and only when accelerating. As soon as you stop accelerating or come off full lock the noise stops. I can only assume it's the new CV joint as it only made this noise when it was fitted.
 
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Another update.

They replaced the CV joint which gave the same noise again. To cut a long story short, the supplier investigated and found small perforated holes in the metal! They suspect that the batch must have some casting fault during the heating process. They are trying to resolve it and will be fitting a new one when they work out what's going on and rectified the issue.
 
Another update.

They replaced the CV joint which gave the same noise again. To cut a long story short, the supplier investigated and found small perforated holes in the metal! They suspect that the batch must have some casting fault during the heating process. They are trying to resolve it and will be fitting a new one when they work out what's going on and rectified the issue.

Which brand are you using?
 
I don't know, I did ask but all I got was, 'we've never had any come back with them before'. I knows not GKN as they were having a discussion amongst themselves whether this one would be better or worse than a GKN. The only thing I can tell is that the boot is much higher quality than the GKN one I had before.
 
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