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Fixing a cracked case
type_one - March 11th, 2004 at 03:28 PM

I have a case that has a hair line crack appearing in the rear flywheel area behind, you guessed it, number three. It is no where near through yet and does not leak yet. Can I get it welded and be sure it will last a while or is it time for new case. Money is an object but I don't want to spend heaps on fixing it if it is still going to crack again.

All comments and help appreciated. I do realise some people are dead against this. I just want to hear some differing opinions.

Thanks all.

vw54 - March 11th, 2004 at 04:50 PM

Time for a NEW case or a good S/H one if you can find it.

It can be welded if you can find someone who can do magnesium welding but the preperation and cleaning is extreamly important and if not preheated and post weld heat treated the case will only crack again.

Then after welding the case will need tunnel boring and the mating faces machining to ensure a good flat surface to rebuild your engine.

So in the long run cheaper to get a NEW case, especially if your keeping the car for a while

Menangler - March 11th, 2004 at 05:02 PM

They are not worth welding, just buy a new one.

Bizarre - March 11th, 2004 at 05:59 PM

I agree

I saw in VWMA cases advertised for under $700!!!

Not worth scratching yourself for that price!

VWCOOL - March 11th, 2004 at 06:14 PM

You have nothing to lose by trying coz u gotta get a new case anyway...
I've had 4 cases go in the last 15 years - I know why, and it's not really 'case' related - and geez, it sucks duznit?

helbus - March 11th, 2004 at 09:52 PM

A friend of mine was offered the cheap option of welding a crack in his case in the vehicle, with no guarantee.
You guessed it, it cracked again, so he paid again. The cheap option again.
You guessed it it cracked again, and he was the one who started getting upset.
If I was the mechanic involved I would vow never to weld another case again.

I can see it would have been better to remove the motor, strip it down and weld it then, but if you have to do that and machine it to get it spot on, then yeah you might as well replace it.

vw54 - March 11th, 2004 at 10:58 PM

Quote:

I can see it would have been better to remove the motor, strip it down and weld it then,




The ONLY way possible to weld acase id too dstrip it down. I forgot to mention this before its must be pulled apart and cleaned before you cqan even think about attempting this,

I only did a few case because i worked at Qantas wheere i has acces to the BEST welders and heat treating section in Australia or the world for that matter....

By the way i was the metalurgist who was doing the preperation and heat treatment on the weding processes. Not the welding i left that to the Experts... mind you i watched and assisted

tonyg - March 12th, 2004 at 06:58 AM

I have repaired a case with similar cracking and was leaking with small piece of alloy from a wrecked case, epoxy resin and alloy dust from grinding case material... drove 12000 k's in 6 months, still ok when sold. Make the resin into a paste with the gound up alloy, seems to reinforce the cured product. I think the epoxy has enuf flexibility to avoid cracking again. Make sure everything is clean with emery and acetone. If $$$ tight, may keep you going for a year or more......