Weld X member to trunk floor

[NZ 70 RR]

Hi guys,

Hope the drawing below helps explain my question. When I fit my X member up to the trunk floor it makes contact with the tabs on the end of the frame rails and the indentations of the new trunk floor. Are these the only contact points that I can weld the x member too ? Should the x member and floor be touching all the way along ? Am I having this issue because I am putting the x member in in the wrong order.
help please
Tony

 

[Propwash]

Hey tony, that top lip that curves over on the x-member, should mate up all along the trunk floor above it. I used an AMD crossmember on my bird and had a little bit of a problem getting the X-member top lip and bottom side of the trunk pan to sandwich together tight. I drilled some pilot holes across, as well as the 5/16" holes for the spot welds, and ran in #10 sheetmetal screws to pull them together tight. I had no issue with the tabs off the frame rails interfering with the fit between the two. Obviously screws come back out and are plug welded up when done.

Is it possible to take a pic or two? Good work on the drawing, but a view or two at different angle might help me understand where exactly you're coming from.

 

[NZ 70 RR]

I am going to take some photos right now. Post them soon. Might be 30min or so, due to our time differences you might not want to stay up to late waiting. Thanks for the reply and kind words on my drawing.
Tony

 

[NZ 70 RR]

pics of problem

hope these help

- - - Updated - - -

Drawing shows 2 indents, there is only 1 on each side. 1st pic shows the indent and 2 rail tabs. When x member is pushed up tight on these there is a gap of 2-3mm between the x member and floor. I used a white ruler hoping you can see the gap better.
Is it an option to weld a strip on metal the thickness of the gap to the top lip of the x member . Leave out section where indent and tabs are, then push up to floor and plug weld from top ?

- - - Updated - - -

Is this an option

 

[Propwash]

Sure do. Thank you. Back in the day that was pinched together with a pretty hefty machine, mashing into place. Now days, either the X-member doesn't have the proper recess in/down, under those tabs.... or the trunk pan doesn't recess up inside to allow those tabs to sit flush with the rest of the pan. Looks like you have already welded the tabs to the trunk floor. If I was in your shoes, I see a couple of options. One would be to cut the crossmember under those tab areas from one side of the frame rail tab to the other. So like a 3" long cut on each the left and the right side/rail. Then remove 1/8" inch of the vertical metal and re-weld. Should sit flush then. Other would be to eliminate the tabs all together, and cut out and weld flush the small indent. Your pan is already tied into the frame rails all the way down, so you're not loosing any real structural support. The ears of the at the end of the frame rails mate up to the X-member anyways, so not loosing any real support there either. I believe that indent was put there to replicate the factory look and that is it, but back in the day when they built the car, that indent was a press/pinch area for the jig that would sandwich it all together back there, thus leaving an impression in the metal. It's the joys of aftermarket parts my friend. Never a turn key moment.

Hope it helps....Gotta go for now, but i'll be back on in a few hours.

 

[NZ 70 RR]

Thanks Propwash,

Both options sound good. Will talk with my panel guy and we will pick which one to go for.

Tony

 

[Propwash]

Not a problem at all Tony.

A metal strip across the top, like you show would work as well. Might be a little more work, but would definitely do the trick. If you go that route, be sure to spray on a hefty amount of weld-thru primer between the strip and the top lip of the x-member, before welding the two together. Lotta moisture/wash up in that area being the very back of the car. Any means you can seal up any seam back there the better.

Good luck amigo!