Shaft fell off

[Milkky]

Hi
After some advice please. I'm not a mechanic and wouldn't claim to be one which I why I use garages.....anyway....

Bought an A4 some months ago and it failed it's recent MOT on a couple of things. One of which was a broken coil spring. As I work for a car parts company one of garages I deliver to said he would change the spring "for a drink".

After a failed first attempt they got it changed all good. MOT retest and pass yesterday happily drive off the forecourt and BANG. Drive Shaft on the (passenger) side they replaced the spring fell off, couple of bolts on the floor so the MOT place kindly put it on the ramp and put them in to get to the place that did replacement.

They apologised profusely and said they would sort it out Monday, new bolts from Audi etc etc and obviously don't worry about the drink.

Checked today and as photo shows it's split the bolts on the casing in the picture. Took it back today he said as nothing's leaking it should be fine and he will replace these other bolts and it will tighten up.

Questions i have Are

is this safe ?
Should they replace this plate/casing really?
What's that plate casing that's cracked actually called?
How do bolts come out anyway? Apart from not tightening. My worry is this happens again when going at speed with family in the car.

Also where do I stand legally if it needs expensive replacement parts.

Hope that all makes sense.

Thanks
Ignore this photo it's the one in the album below
[album=medium]4238[/album]

 

[NHN]

How the fxxx did that casing get like that, wow some pressure on that to crack like this.

 

[Milkky]

Hi
Thanks for replying, have i got it wrong ? I thought it might have been where the shaft flew up and hit the bolts as the guy said they look bent, is it not that ?

Cheers

 

[NHN]

Well its possible, however overall that casing is sealed for a reason, although the cracks are on the outside edge, it could now present 2 issues, 1st the bolts are bent in the threaded hole & may be difficult to remove without damage of the hole requiring either helicoiled if enough width or tap a new thread, but I'd be more concerned the cracking not compromising the seal to the internals from external debris, dust.

They really need to repair all the damage as you now have 2 weak fixing points from the 8ish, thats not a good thing.

Tell them it needs to be fully repaired.

 

[OliNix]

You 100% need a new diff cover. To me this looks like a diff failure not a shaft or bolt failure.chances are if you replace the shaft it won’t help.

 

[NHN]

Im not sure i agree, look at the black markings on the bolts damaged, that look remarkably like the markings on the shaft points, plus the other bolts have clear marks on them too, that shaft has spun & whacked those points hard & caused that imho, the markings & colourisation tell a story I believe & those are fresh cracks, old would be matching colour of surrounding area, clearly theyre not.

 

[Milkky]

I appreciate the input Olinex but I think NHN is right. The top bolt you can see the rust marks where it hit it. Question i wonder about is a repair is possible/safe or does it need a new cover/plate. I'm happy with a repair if it's safe and the guy is genuinely sorry it's happened.

I've called a local Audi dealer today they will check over the repair for free and quote for work needed if it's not acceptable.

 

[Milkky]

This picture shows more. See the chunk out on the left side ?
Luckily I think it's outer casing and not smashed through. No leaks anywhere anyway.

 

[NHN]

Yeah i saw that too tbh.

 

[OliNix]

Yes I see, this will not be repairable though was my main point. The cover takes differential loads. A cover should not be too expensive, but it is if it can be bought separately.

 

[Milkky]

Ah got what you mean now cheers
Any idea what it's priper name is ? Ive tried searching but can't find it listed as a part. Maybe Audi can help tomorrow

 

[Milkky]

Ah got it.

Diff cover....

Duh..............

 

[Dani_B19]

Wow.

 

[i3oricua]

Wow, that is crazy. When replacing axles you "should" replace the axle bolts too since they are stretch bolts. They obviously reused the bolts, which admittedly I have reused mine but I at least put some blue loctite on them.

I'm the type of person that usually takes risks when it comes to my car but with that damage I wouldn't risk running it like that. I'd make them replace it, as someone else stated, the evidence is obvious as to how that damage happened. Good luck. I hope it gets sorted out.

 

[Milkky]

Hi i3oricua
Thanks for the reply. It's interesting as I'd read about those bolts being One time use and asked the manager if they were and he said no you can reuse them. Then when i went down the mechanic said he us getting new set from Audi for me.
My quandary is can I chase them to fit a new part if it was done for "a drink" as in not officially charged. I didn't ask for that way I asked for a genuine price first and he said he'd do it for a drink. In his defence nice thing to do, in my defence damaged car.......

 

[OliNix]

I have been having a think about my not too, expensive statement and whilst yes the cover shouldn’t be too expensive it’s the skills and cleanliness needed to change it. Your best option to find one would probably be a breakers yard or transmission specialist for the cover. It is not simple to change either as the diff has to come out and be taken apart to change the cover as it has a flange to mount to the axle. This you will need the transmission specialist to replace.

Given all this, it is Most likely cheaper to just change the whole diff.

Not sure where you are in the country but you can try 3D transmissions in Reading. At the very least they should be able to quote from the pics.