Chassis Cracks W116

[Oversize]

So this is what I was so shocked to discover during my inspection of Blue Flame. Initially I thought I was seeing things and didn't really believe it. But a closer look confirmed my suspicions. I suspect it's been caused by driving (or being towed) with collapsed hydraulic suspension, or by towing something largish. After having a look at some W116 tow bar designs and their mounting points I don't believe the W116 was designed with towing in mind. The only way I can see that the cracks can be properly repaired is by pulling out the entire rear subframe, rear seat and fuel tank. An access hole may need to be cut in the inner wheel arch area. The very tip of the cracks should then be drilled in an attempt to halt their progress and then welding should commence. I'm also wondering if the upper coil spring saddles should be replaced with heavier duty ones. My only concern there is that the original ones have cut-outs towards the rear and these may be to allow strut clearance....

Right rear wheel arch with the wheel off. Note the fresh marks are where I used a chisel to remove deadener and see the extent of the problem:



A closer look from underneath:

 

[Oversize]

It crossed my mind that it could've been caused by a collision, but a look on the left side dispelled that notion . Initially it was hard to see (apart from the cracked saddle):







This last one shows the left rear bump-stop mount and I'm concerned that's also developing a crack:



The moral is don't rely on even a paid 'professional' inspector, as these things can be missed, unless they take the time to be thorough. And on a 6.9 a thorough inspection could easily take a whole day.... Please have your car/s checked in this area, as a complete failure would write off the car and quite possibly cause a monumental collision.

 

[SEL_69L]

I know of a 6.9 that had to be wrecked for parts because the floor frame rails were cracked and had a jerry job done on the repair.

The car had to be condemned.

Pity. It had covered 180,000 kilometres, with all documentation since new.

Some clouds have silver linings.

The gearbox out of that car is now in mine.

 

[Tony66_au]

HOLY CRAP!

Jesus Mark thats so damned sad mate.

If the damage stems from the rear suspension then perhaps a cell failed causing the system to go rock hard and then driven for a few months.

I experienced this with my Wagon and even a few weeks with the hard rear suspension was enough to flog out a mount on the rear subframe.

A good welder will be able to repair these cracks though and then with regular inspection the old girl should be good to go.

 

[Tony66_au]

By the way, it is often the case that a repairable car is scrapped due to loss of confidence in the cars structural integrity (Which was the case with AAB007, although Alex was happy to repair and continue his good wife was not so happy).

I will say this though, I have sectioned (Disassembled) many cars and on their way to restoration remedied inadequate factory welding on just about every cars Ive worked on.

And a good penetrative weld with the correct filler or wire (Tig, Mig or Arc) will have far more strength than the factory tac welds or spot welds and with a bit of metal finishing you wont even know the repair is there.

 

[Oversize]

Fortunately I have some contacts and might be able to convince someone with a great deal of experience welding chassis on V8 Supercars to give me a hand. I won't be giving up on this one. It'll just have to go on the backburner for now until Red Bull is up and running...

 

[WiSeGuYY]

Sad NEWS MARK , but i'm sure this Issues can be solved , from looking at the cracks in the pics , i only need master welder who can fix those cracks once and i hope for all.
it need cleaning to see who deep the cuts are and hope it is curable.

Good LUCK , it is a keeper , the car looks great indeed .

REGARDS
TAREK

 

[Styria]

Hi Mark, a bit of a shock to the system, but I do think that the welding should be reasonably straight forward unless, of course, you need to remove the subframe, fuel tank etc. Once you need to remove the frame, you're going to be right into it.

I am very sorry to see this happen to you - looking at the general underbody appearance of Blue Flame, it seems evident that the old girl has led a somewhat neglected life. Good luck with this work. I also looked at the number of items to be attended to in another post, and I am gob-smacked. Regards Styria

 

[Helmet]

Sorry to see those cracks, IMO welding is only a temporary solution as the metal is fatigued and weak. It must have a done a lot of hard km to get to this stage.

 

[Tony66_au]

Helmut Chassis cracks are caused by different things mate, some design inadequacies and sometimes abuse such as blown SLS pods and rough roads.

Nice fat welds usually sort out any crystalline fractures as does Tig welding with a good sized "flame" and the right filler rods as does varying the amount of carbon in the filler.

Failing that the addition of gussets or plates will often relieve the load as well as a follow up xray and although it sounds a bit high tech xray welding is a common enough practise.

As a rule a good Tig welder experienced in steel will be able to do the job with minimal fuss and often in situ with bugger all disassembly.

 

[Styria]

Hi Mark, I've dug up this old post of yours - I guess you've pushed this job aside in favour of getting Red Bull roadworthy or have you already had it fixed ? Regards Styria

 

[Oversize]

Nah she's been put aside for now along with the new Centras. She does get a kick in the guts every now in then just so I can have a listen.....