SG NO OPTIONS CSL 17950 Miles

[nw942]

I was told that it's usually the rear left subframe mounting point that goes first, so obviously there is extra loading in that corner. If you look at some pictures of the underneath of the car, the main difference between the left and right is the presence of the differential mounting on the left hand side. So one possible cause is that maybe the differential bushing starts failing first, which leads to extra play and then knock on stresses to the rear left subframe bushes/mounting.

Obviously more aggressive driving and more violent gearchanges will affect the bushing, and I also suspect it will be exacerbated as the bushing deteriorates with age.

This is just a theory, so happy to be corrected.

[knoxville]

Originally Posted by Trawler

Thought I would ask someone who knows a little about the subject of steel & supports.

Hope I repeat this correctly. The problem we are experiencing is related to fatique life not how old the car is. The area in question is being exposed to loading & unloading. The magnitude & frequency will affect the fatique life. So theoretically if the life is 1000 cycles at a given load once this is reached the material will crack. If we expose the car to 900 in its first year & then 10 each year for the next ten years the failure will occur after 11 years. 500 each year then the life is two years. If the loading/unloading is higher or lower it will affect the fatique life exponentially. Interestingly he also said the SMG is also probably contributing to the fatique life. He wanted to see pics of how everything is supported connected so he could give a better explanation.

That's exactly it. S6, sticky tyres and drifting will all contribute increased loads. But where's the fun driving like a minge for the sake of what, £2k?

[shimmy]

Originally Posted by nw942

I was told that it's usually the rear left subframe mounting point that goes first, so obviously there is extra loading in that corner. If you look at some pictures of the underneath of the car, the main difference between the left and right is the presence of the differential mounting on the left hand side. So one possible cause is that maybe the differential bushing starts failing first, which leads to extra play and then knock on stresses to the rear left subframe bushes/mounting.

Obviously more aggressive driving and more violent gearchanges will affect the bushing, and I also suspect it will be exacerbated as the bushing deteriorates with age.

This is just a theory, so happy to be corrected.

mine went and was fixed in 2010......so sometimes the garage queens do fail early

[Rick H]

Originally Posted by knoxville

That's exactly it. S6, sticky tyres and drifting will all contribute increased loads. But where's the fun driving like a minge for the sake of what, £2k?

" . . . driving like a minge . . ."

[LeinsCSL]

Originally Posted by Rick H

" . . . driving like a minge . . ."

[Mike R]

Where all the trouble seems to stem from is the mounting hole is just too big and allows too much movement. I suspect it is like this for alignment purposes, but a friend who has done loads of repairs to these is yet to see one that hasn't lined up perfectly after being refitted (German tolerances being what they are LOL) and so he is looking to make sleeve for the bolts so that there is zero play (and hopefully then no yawing effect to cause the cracks). I'll keep you posted.

[Jonnymaz]

Very topical for me, just diagnosed with a crack in the subframe

It's probably been asked before but is there any merit in trying to get BMW to pay/contribute? Local BMW dealer and customer services not much help, just said they could confirm the crack and then apply to BMW, but said nothing about whether it is worth doing.

Any experience after the 10 year cut off? (it's a 53 plate).

If not presumably someone like Bartletts to fix it?

[cslsuperfan]

Originally Posted by Jonnymaz

Very topical for me, just diagnosed with a crack in the subframe

It's probably been asked before but is there any merit in trying to get BMW to pay/contribute? Local BMW dealer and customer services not much help, just said they could confirm the crack and then apply to BMW, but said nothing about whether it is worth doing.

Any experience after the 10 year cut off? (it's a 53 plate).

If not presumably someone like Bartletts to fix it?

Gareth's your man @ Barts.

[Jonnymaz]

Gareth was the one who found it! Damn you Gareth

Just can't believe we are all experiencing systematic failure and now having to pay for it!

[jupe777]

Originally Posted by Jonnymaz

Very topical for me, just diagnosed with a crack in the subframe

It's probably been asked before but is there any merit in trying to get BMW to pay/contribute? Local BMW dealer and customer services not much help, just said they could confirm the crack and then apply to BMW, but said nothing about whether it is worth doing.

Any experience after the 10 year cut off? (it's a 53 plate).

If not presumably someone like Bartletts to fix it?

My car was outside the 10 yr warranty when the subframe was found to be cracked. It had previously passed as ok by a lesser dealer just inside the warranty period. It clearly wasn't as rust could be found in some of the cracks. Anyway I paid to have it properly checked at Elms Bedford who then found cracks on both sides. Elms said they would put my case forward to BMW UK and it came as a big surprise it was accepted :-). Only thing I had to pay for was the hire of the jig. The car had a warranty that had ran for a few years which I believe helped but I also think it makes a big difference who is putting the claim in. Defo worth a try to get it through BMW. Good luck.