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Front chassis damage


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Out driving yesterday, noise from front followed by new negative camber on front n/s. I think this will need more than some gaffer tape. Anyone had anything like this repaired? Other side looks fine, the car was restored body-off in 1995, including extensive chassis component replacements but I guess they rebuilt only the parts that needed it at that time.post-13727-0-33894800-1464454111_thumb.jpgpost-13727-0-80801400-1464454173_thumb.jpgpost-13727-0-51722700-1464454179_thumb.jpgpost-13727-0-03738800-1464454185_thumb.jpgpost-13727-0-18280200-1464454190_thumb.jpg

Edited by Phil Pope
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Phil,

 

Sorry to hear about your misfortune. As mentioned, how did it happen? I'm assuming that the wheel has gone up, maybe the upper wishbones have sized on the shaft, which has pulled the mount from the spring tower and then the chassis leg has ripped at the front?

 

I'm sure Colin Matthews at CTM could fix it for you.

 

Good luck

 

Paul

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Yikes thats a very unusual place for a break to occur, I was fully expecting the usual break on the lower inner mounting. That was either a very large and deep pothole or as previously stated something else has seized,either the top inner mounting bushes (which is unusual) or top ball joint. Not a five minute job to repair and I think you may need the top from another turret to repair it properly.

Stuart.

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Ouch, that looks bad, Phil. :(

 

I would be interested to find out how the damage circled below has occurred. As it is on both sides, I assume prior to the spring tower cracking?

 

post-197-0-55650800-1464490199_thumb.jpg

 

post-197-0-78525900-1464490214_thumb.jpg

 

Cheers

Graeme

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Ouch! But old metal does fatigue... and not helped by what looks like oversized tyres?

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Blimey Denis, you really pick your time when Phil is in trouble to drive home your point home repeatedly on oversized tyres.

 

Really not good form old man! :angry:

 

Get a bloody life, if you cannot add any valuable comment butt out.

 

Cheers

 

Mike B)

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No idea about the circled bits, sorry. The tyres are 185/70 Vredesteins-not really oversized surely? Although to be fair it has worn 195/65s on steels most of the time-but considering USA TR6s had 185 tyres neither seem excessive to me.

Edited by Phil Pope
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Puzzling that we dont we see more failures like this, is it a one-off?

I wonder if the indentations on the wishbones that Graeme spotted, and the fracturing, was caused by

the upper bracket fitted reversed, a common ploy to add negative camber. That puts the pivots further inwards. On droop the bracket would be levered upwards using the indentations as pivotpoints. The offside would see lower forces due to road camber, so remains OK.

But why dont we see many more fractures ?

Peter

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Puzzling that we dont we see more failures like this, is it a one-off?

I wonder if the indentations on the wishbones that Graeme spotted, and the fracturing, was caused by

the upper bracket fitted reversed, a common ploy to add negative camber. That puts the pivots further inwards. On droop the bracket would be levered upwards using the indentations as pivotpoints. The offside would see lower forces due to road camber, so remains OK.

But why dont we see many more fractures ?

Peter

Even with the brackets reversed Pete you wont get that sort of contact anyway, I still think it maybe a combination of a seized pair of bushes and a sudden deep pothole. I dont think I have ever seen that type of break before and I have seen some pretty bad chassis over the years.

I think it would be an idea to talk to Colin at CTM and see if he has seen anything like it. http://ctmengineering.co.uk/wp/

Stuart.

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Hi,

 

Sad to see the damage to your car.

 

Looks to me like the weld around the damper tower has been fractured for some time, as evidenced by the rusting to the weld line around the curved turret.

 

If that weld has fractured, it would leave the fulcrum mounting plate only located on three sides, and it is two of those sides that have subsequently failed allowing the top to effectively tear off, complete with the fulcrum and top arms.

 

You may be lucky and find that the damper tower and surrounding areas are still in the correct place and its just the plate and captives that need replacing.

 

Having worked on a few TR chassis over the years its unnerving how minimalist some of the original welding actually is.

 

Maybe wrong but that's how it looks to me.

 

Steve

Edited by Steve Zodiac
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Hi Phil,

wow - that's a corker of a crack in pic 1.

The fracture face looks clean enough. It must have popped in one mighty burst - hence the bang.

 

The design is a little weak there are I'm surprised, if all are like that, that it is not a common event.

 

Where the top plate joins the weld of the front vertical section must be serious stress raiser.

If the outer edge of the top flat plate had the edge turned over to make a small flange it would not have cracked.

 

Sadly hindsight will not help you now.

 

Good luck with the repair.

 

Roger

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  • 6 months later...

Maybe this thread offers a clue to the cause:

http://www.tr-register.co.uk/forums/index.php?/topic/60379-trunnions/page-2&do=findComment&comment=508932

- shocker allowing too much droop and perhaps the upper wishbone clouts the chassis whenever suspension is at full droop?

If incorrect shockers and excessive droop are causing turret fractures I'd expect other owners to find witness marks in the edge of the turret or on the underside of the upper wishbones, or both.

Peter

Edited by Peter Cobbold
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Blimey Denis, you really pick your time when Phil is in trouble to drive home your point home repeatedly on oversized tyres.

 

Really not good form old man! :angry:

 

+1

 

And as it turns out incorrect.

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Regarding turrets, these are the only thing that CTM don't make for their replacement chassis which is why you have to supply an exchange set. I'm not sure how much of the original gets used but to me the bits that have failed seem to be all flat plates. I would have thought any decent fabricator could knock up replacements.

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Long time since I've seen a turret go like that . . . . . but it wasn't unknown back in the 70s and 80s.

 

I do remember a TR6 suffering just the same result on a private practice day at Goodwood, the car barrel rolled and the rollover bar just skimmed the grass, car inverted in mid air !

 

Usually it seemed to be a consequence of three factors, singly or combined . . . . .

 

a) a particular version of uprated shocker, slightly over length

 

b ) useage of ER70 tyres (205/70 in modern terms, as in XJ and V12 E)

 

c) neglect of greasing of the suspension

 

That's in reverse order of likelihood, sheer neglect and big boots were, I reckon, the main culprits.

 

Often enough the chassis lower mounts had already been successfully repaired, and the turret went some time later . . . . .

 

Cheers

 

Alec

Edited by Alec Pringle
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Have seen this on a race car with big sticky tyres.

Also something that happens in accident damage. These pictures show rust on the cracks so may have been building up over a period of time, something we all should add to our check lists i think.

 

 

Roy

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