Rear subframe cracks...

[John Green]

OK, so we all know about the front subframe issues with the SL and SLC's. But now it would appear that I have found a new problem with the rear subframe. Check out these pictures from a 350SLC that was towed in here on Friday last week.

DSC01140.JPG

DSC01141.JPG

DSC01142.JPG

And then the finished product, owner was hearing some funny noises for a week and then wondered why it had so much negative camber on the rear wheels.

DSC01144.JPG

Looks to me like the crack started at the holes for the front diff bolts, may be worth checking for all you W107 owners out there.... :?

[AndrewsSL/SEL]

Thanks for the heads up John! :shock: :shock:

[AMG]

Definitely unusual. I wonder if that particular vehicle was ever involved in a rear-end collision at some stage, or if this is more likely to age / lack of maintenance ?

[John Green]

From what we could see the rear floor pans were fine, no evidence of repair and things like the subframe mounts and diff mount were fine......

Another interesting point is that when you look up the replacement part on the EPC you find that it has had the same part number since day one, in other words MB have never flet the need to modify the original design. So must not be a common issue...

[AMG]

I guess one conclusion which could be drawn from that is that the vehicle may have had a hard life in it's travels and that the cracking was likely due to fatigue.

Still, not a bad effort when you consider the age of the car. It's certainly the first time I've seen or heard of it, and there were a lot of 107's made over those 18 years.

Rare occurrence though it may be, I'll still be checking Lurch & Stella out when I get home :)

[merclover]

Thanks for that john il check mine out tomorrow cheers.

[Mercmad]

I've never heard of it before . That car might have been used in the outback?
Normally 107's rust away before fatigue becomes a problem.
heres one I saw on my visit to the mercedes graveyard ..Nice rust free 450 but no interior....

John Freemans place 2012 078.jpg

[CraigB]

Not sure where all the stresses are in these, but for example if a bolt wasn't correctly tensioned over many years and therefore minor movement/vibration, could that explain something like this?

[John Green]

Well it has been three years since that job, but from memory the diff bolts were all tight. Your theory however is quite possible...

[AMG]

Figured I better close the thread off with the factory service manual documentation regarding subframe dimensional tolerances.

33-600.pdf

35-410.pdf

35-420.pdf

35-430.pdf