Stupid rear crossmember alignment question

[Tetsu0san]

Hi all

I'm currently replacing the rear quarter on my 90 chassis and I have a question about alignment. If I read the diagram in the repair manual correctly there is a datum that runs from the front of the chassis to the rear, passing over the high parts (labled 'B' on the attached immage).

It difficult to see but does this datum line up with the holes on the upstand tub mounts on the rear crossmember? For my untrained eye it would appear so, but on my chassis these holes are 10+mm down on one side and 20+mm down on the other. It's been welded quite a bit in that area, hence chopping it all off and replacing it with nice new metal, but if I am reading the diagram correctly and these holes are meant to be ligned up then I didn't expect it to be so far out.

Cheers

[Phill B]

Could be a number of reasons why yours is off. Mine was off ~7 mm too.
Twisted chassis from offroading, accident, etc. Too much heat put into the chassis from welding, supported incorrectly while welding.  I think mine was from the previous owner over-welding. Professional welders tend to break up welding jobs so as not to put too much heat into one area at a time, DIY'ers tend not to consider that I think.

I corrected the right rail twist on mine by removing the left rail axle stand and welding. It then bent back to shape due to the weight/heat put on it.

[Tetsu0san]

12 minutes ago, Phill B said:

Could be a number of reasons why yours is off. Mine was off ~7 mm too.
Twisted chassis from offroading, accident, etc. Too much heat put into the chassis from welding, supported incorrectly while welding.  I think mine was from the previous owner over-welding. Professional welders tend to break up welding jobs so as not to put too much heat into one area at a time, DIY'ers tend not to consider that I think.

I corrected the right rail twist on mine by removing the left rail axle stand and welding. It then bent back to shape due to the weight/heat put on it.

Yeah, I think putting patch on top of patch etc hasn't helped on this chassis. It's a bit of a mess....

But I take it from your comments that I am right in thinking that the holes are meant to line up with that datum.

[Phill B]

Yeah, I used a similar diagram to that. The B Line was correct on the left rail, off on the Right. And the tub support dimensions were as they are in the diagram, give or take a mm or two.

[Tetsu0san]

1 hour ago, Phill B said:

Yeah, I used a similar diagram to that. The B Line was correct on the left rail, off on the Right. And the tub support dimensions were as they are in the diagram, give or take a mm or two.

The outriggers? Mine are again quite a long way out, but as these are slotted I'm not too bothered.

My issue is that as I'm going to be removing the chassis from more or less the three bolt holes for the shock mounts on the rear I need to get as much right as I can before I start chopping. So far the chassis doesn't look twisted at all, and with two rails put along the chassis to create 'B' it all looks pretty good, except for the crossmember tub mounts.