I'm thinking of getting my 12 bolt axle tubes welded to center section to keep them from twisting. I got a chance to run the vehicle in and have it done, My question is it ok to have it done when mounted on the car or do I have to remove the rear end and have it done ?? Thanks

I always thought that to weld the tubes properly, the rear needs to be in a jig.

I wouldn't think a jig would be needed but it would have to be checked for straightness after welding.

if you want it done right the best way is to completely disassemble and install a fixture otherwise you risk warping the tubes. a lot of rear ends are not straight to begin with and this is a good time to address that