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Chassis leg replacement

Posted: Mon Sep 26, 2011 11:14 am
by morris1961
I have finally come to the conclusion that a new L/H half chassis leg is needed. I was wondering what ways are there of lining the rail up without using a jig or removing the engine? i have never done something like this before so I'm pretty clueless!

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 12:30 pm
by bmcecosse
I think if you search - there are many threads on the subject. Best way I can suggest to line it up will be to put a snug fitting bar through the eyebolt hole on the remaining leg - and pass that through the eyebolt hole in the new leg - clamp it all up and weld into place !

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 12:42 pm
by morris1961
yeah, that's what i'm thinking. haynes restoration manual doesn't say anything like that. it has to be seam welded as well as pug i presume?

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 12:44 pm
by Alex'n'Ane
Can I ask where it has failed? I posted a thread recently about this, and I personally would advise adding some strengthening to the inside, as this is the place both of mine failed (especially if your planning to drive at all enthusiatically)

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 12:53 pm
by Alex'n'Ane
morris1961 wrote:yeah, that's what i'm thinking. haynes restoration manual doesn't say anything like that. it has to be seam welded as well as pug i presume?
Both the ones I removed (poss original) were just stitched along the engine bay floor section. On mine they are now seamed, and seamed and plugged at the thinner section and joint.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 1:23 pm
by morris1961
ive not driven it as yet but its gone around the eye bolt. im really dreading this job! i cant really see away around me removing the engine and gearbox if im honest....

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 1:32 pm
by Alex'n'Ane
Both the ones we did (not at same time) we did just with everything in place, on a 2 post lift :p, measured carefully first and tried our best to make sure nothing else moved. As always you can't neccessarily trust what's there currently though for precision.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 1:40 pm
by morris1961
oh fair enough, there's a bit of hope for me then!
I'm feeling a little more confident about it now :D

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 7:40 pm
by Fingolfin
If leaving the engine and gearbox in, I'd NOT do it underneath, with the car sitting on the ground (that's a lot of weight to fall and crush you). If at all possible, get a rolling jig, which not only will allow you to tilt the car to an easier and safer position, but will also help hold the shell in shape while cutting the leg out.

Best conceivable way IS to do the job with the engine and gearbox OUT. Trust me, I know...I've replaced one and a half legs on Mog... :lol: And do consider adding some extra stiffening, like Alex'n'Ane suggests. Don't dread it; it's not as terrible as it seems at first.

The legs are indeed spot-welded on -- perhaps sixty to eighty spots on either side of the leg -- but when I put Mog's new legs on, I seam-welded the whole replaced length, in addition to quite a number of spots along the inner lip of the flange, where possible.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:01 pm
by Alex'n'Ane
If you have access to a 2 post lift its a dream.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:34 pm
by morris1961
I think its best to remove the engine and gearbox. make life a lot easier.
I've heard that because it would only be half the leg replaced, it has to be seam welded. is this true?

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:38 pm
by bmcecosse
Certainly will need to be seam welded where it joins on to the remains of the old leg..... But stitching should be fine where it joins up to the engine bay floor.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:41 pm
by morris1961
i see...
a few people told me because its not a full leg the mot people will class it as a patch and would have to be seamed everywhere...
maybe i should ask my mot bloke!!

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:45 pm
by Fingolfin
I think Roy's right -- but then I'm not the MOT man! :lol: As I've said before, in America we have a whole different paradigm for vehicle inspection (not better or worse, just different).

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 8:54 pm
by morris1961
i hope he is right!!

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 9:14 pm
by Alex'n'Ane
Tbh once the welds are ground down, and all undersealed etc, you shouldn't be able to tell its a repair panel anyway, or at least not where it joins.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 9:15 pm
by Alex'n'Ane
A good strong weld (or a few :P) is the most important thing.

Re: Chassis leg replacement

Posted: Mon Sep 26, 2011 9:33 pm
by morris1961
very well said!

Re: Chassis leg replacement

Posted: Thu Sep 29, 2011 6:06 pm
by morris1961
chassis leg ordered and work will commence at the weekend!
fingers crossed everything goes smoothly!

Re: Chassis leg replacement

Posted: Mon Mar 25, 2013 11:38 am
by dik
I am interested to hear how this went... and worried that there has been no reply for a while?

dik