Cracking S7

[blue]

Guys I know this has been spoken about lots of times and I have the usual chassis stress/cracking places on the front that seem so widely known about but what concerns me if it's cracking where I CAN see it where is it cracking where I CANT !!!!

Has anyone come across any other places where the mono splits??

I can easily weld some plates /strengthen the chassis if I know where to look ?

 

[Snapperpaul]

As far as we are aware only the stated places in the engine bay area, I think due to using standard mig wire on stainless and hardening already hard metal.

It would be good to revisit this problem and find out how many suffer, what version of monocoque, how many miles, how hard.

Mines been on the road near 6 years but milage is low

I've fitted the Tie bar mod and Gaz shocks with a 50mm x 25mm box replacing the anti roll bar

Don't know if this makes a difference but the original anti roll bar and Zimmers were so stiff I could jack the whole front up by 1 wheel

[cb750]

Around the engine mount towers (support trays crack)

 

At the rear of the tower support trays near bulkhead

 

Rear of the monocoque where the shock absorber angles or support tubes mount (tubes/angles flex and crack the body)

 

Top of the scuttle cracked on mine where the previous owner had cut a lot of dash area away to mount the sierra instruments

 

Area underneath pedal box front if the box hasn't been strengthened. It twists back and forth when the brake/clutch is pressed

 

Top of bulkhead to monocoque side rails weld has been known to crack

 

Plus those at the front!!

 

My gearbox support angle also had the start of cracking around its mounting holes, I replaced this with box section.

 

All mine were reinforced and professionally welded up

[blue]

Thanks for your replys.

Any pics would be good.

Anyone else had this (see pic).

I'm running 80lb front springs and tie bars.

That happened the weekend. And me and the other half were only cruising as the weather really was not the best. Noticed it while parking it back in garage !!!!

[Snapperpaul]

Ah yes the wishbone top mount pivot

You'll probably need to plate that and pin the bar to stop it rotating with the arm

Some fit a grease nipple in the arm and pump with grease

[cb750]

Forgot about that one! Mine hadn't cracked but the pivot rod had rotated and elongated it's mounting hole. I altered the complete rod system by drilling out the holes and replacing the rod with an m16 HT bolt and flanged nylon bushes plus spacer tubes so that the bolt can be tightened fully but the wishbone was free to rotate. The shim system was kept so that geometry can be adjusted. Grease nipple also added

[Guest mower man]

Thanks for your replys.

Any pics would be good.

Anyone else had this (see pic).

I'm running 80lb front springs and tie bars.

That happened the weekend. And me and the other half were only cruising as the weather really was not the best. Noticed it while parking it back in garage !!!!

I thought I had pushed spring rate to nearly optimum at 120 but you say you are running 80'ies ,thats the lowest Ihave known in nearly 10 years of playing with this set up do you have much roll ? . stds were 180 mower man

[Grim]

... I think due to using standard mig wire on stainless and hardening already hard metal.

 

Standard austenitic grades of stainless can't be hardened in the heat affected zone. What is more likely is that the steel is cold rolled and work hardened, which then gets softened/annealed by the welding process.

[HAWKNORTH]

That cracking looks nasty. My s3 has been on the road for 17 years ( 11 of them in my ownership) . The only cracks I have had so far are the typical tub to front cross member ones. This winter I did the grease nipple in the wishbone mod but was plesantly suprised to find the pin already well lubricated and no signs of hole wear. I dont know what rating the front shocks are or even what make. I have a good look at every weld I can find every few month just to check.

[cb750]

Blue, Just looked at your photo. My cracks were nothing like that! They were only fine stress cracks which were easily welded up. If that is your front suspension pivot rod has it seized in the top wishbone and then twisted in the chassis to cause the tear?

[Guest Ian & Carole]

Blue, Just looked at your photo. My cracks were nothing like that! They were only fine stress cracks which were easily welded up. If that is your front suspension pivot rod has it seized in the top wishbone and then twisted in the chassis to cause the tear?

 

That certainly looks for like a tear than a crack IMHO

[Guest mower man]

Don't like the look of that at all [sorry ] some thing is definitely wrong there was a scots guy had trouble like this way back and the front susp collapsed ,is thepivot not supported by an angle iron frame across the tub? , it certainly needs some serious investigation mowerman

[Grim]

Blue, you've not told us where the crack is located.

 

I've only just noticed the photo. It's most likely that it is a fatigue crack which has been bent open.

Edited March 28, 2014 by Grim

[blue]

hi thanks for your replys

ive stripped the front down and found the bolt more or less stuck solid in the arm so at least ive found the problen

im still amazed that the rfont arm is only sitting in a bent bit of 2mm stainless steel

hi as regards to body roll on 80lb shocks its very minimal but thats only on back lane blasts have not taken it to limits on track yet

also has anyone come across a very big (noisy) bang from the rear of the car if going over a pot hole !!

ive read the posts on the bottom of the car (subframe ) hitting so have checked this ( put talc power over bolt heads etc ) and nothing was rubbed off after a drive ??

and it only happens fron near side never offside !!

[Guest mower man]

hi thanks for your replys

ive stripped the front down and found the bolt more or less stuck solid in the arm so at least ive found the problen

im still amazed that the rfont arm is only sitting in a bent bit of 2mm stainless steel

hi as regards to body roll on 80lb shocks its very minimal but thats only on back lane blasts have not taken it to limits on track yet

also has anyone come across a very big (noisy) bang from the rear of the car if going over a pot hole !!

ive read the posts on the bottom of the car (subframe ) hitting so have checked this ( put talc power over bolt heads etc ) and nothing was rubbed off after a drive ??

and it only happens fron near side never offside !!

repivot only held by 2mm sheet ---- it should not be !!!!there is as I posted earlier some thing amiss more photos please , its not a get at but an offer of help , there are a few things to address pm your home [postal adress ] and I can send some pics ,hard copy of the front end on my car HTH mowerman

Edited March 28, 2014 by mower man