Rear shock crossmember

[Challenger340!]

so I have owned a 72 challenger for 20 years the car came with air shocks in the back this winter I’m changing out springs and shocks pulled the shocks and found the upper mount hole facing the rear is seriously oversized,mushroomed,cracked.
My question is there any fix short of pulling crossmember and repairing/replacing and if so is it spot welded to the floor, I can see where it’s welded to the frame but not anywhere else due to undercoat.
Thanks for any help fellow Moparians.

 

[Adam]

The cross member is surprisingly thin. I don’t think it was ever intended to support the weight of the car.

It is not spot welded to the trunk floor. You may be able to weld it up through the shock hole, but I bet if you get underneath and feel the top and rear you will find more damage.

Here is a pic of my cross member.

 

[Challenger340!]

Yeah that’s pretty bad,you ended up replacing?
So it’s only welded to the rear frame rails?

 

[Adam]

Challenger

Here is a link to my photo album.. start with pic 57.

Yes, it is only welded to the frame rails. If it is really bad you could probably cut it flush with the frame rails and butt weld a new one into place, without hurting the trunk floor. Might even be able to drill out the spot welds from underneath and remove the whole thing... AMD makes a replacement for only $239; I would probably weld some reinforcements on the new piece before installing it, but I like a bit of overkill.

 

[Challenger340!]

Thanks Adam appreciate the info and pictures

 

[340challconvert]

Adam, thanks for sharing those great pics.
Very helpful for many members!

Your advice on the cross member is right-on.
Back in the day, I bought a 71 Challenger vert 383 car for $500. Car look good.
Guy had put air shocks in and ripped the shock cross member up badly.
I took it my Dodge dealer and for $175, they welded a new one right in. It was 1975, hence the low price. Car rocked like a roller coaster all the way to the dealer. The good old days.

 

[budascuda]

Adam I looked at all the pictures in the album, you did an amazing amount of work and the car looks fantastic. I like to know how long it took to do the work, it seemed like you were on a mission.
Also, I would love to know how you kept the alignments, do you think having a datum table is overkill?

 

[Adam]

I did not remove / move any of my frame rails, which were in good shape. If replacing these items a dataum table would be ideal. Most guys don’t have access to one, but I think good results could be obtained by careful measurements, and making sure the car is properly supported.

 

[budascuda]

Yes I agree, tables are handy for doing rails or something structural, that's why I made our's.
But even then, as you mentioned; good measurements when the car is well supported is all you really need.

many years ago I came across a sign hanging above the door to the frame straightening department of an old body shop, the sign said

" let no one unversed in geometry enter these portals".

I think the owner was Greek! Lol