I'm not totally sure I'm posting this where it needs to be but, Today I crawled under my 1980 f150, doing maintenance work and I noticed a shiny spot on the driver side cross member under the oil pan and engine. I got to looking at it more and the rivet that holds the cross member to the frame has severe gashes in it (from the member moving back and forth against it.) and the cross member broke the piece from the hole where the rivet is supposed to be to edge of the member, its gone. So I cant move it back and put a bolt and washers through where the rivet is. The rivet also mounts the shock absorber tower, I thought at first I could just move the cross member back and cut the rivet and install a bolt but since there's nothing there to really hold the cross member that wouldn't work.
I did some tinkering with it and this is a huge issue because the frame twists considerable on the driver side. So much so that about a month ago the fender mounts that are attached to the cab broke on both sides. My fenders don't have any support by the cab. I didn't realize until today what was causing the front end to be so outta whack and break pieces left and right but I know its this now. The frame can twist considerably until it meets the transmission cross member. Which is causing the front left wheel to toe in, the shocks to bend along with the coil spring, the cab to twist, and its putting a lot of stress on the other bolts on the member and frame.
I don't really know what to do about it. I'd like to be able to upload some pictures to here to show exactly what I'm talking about but I'm not sure how to upload pictures exactly. I don't want to have to get a new cross member just because I broke a rivet hole but i don't know if there is another way of fixing it?

 

George - It sounds like you have a very serious problem. And, from your explanation I would say the cross member has to be replaced. But, before going there I think we need to see some pics. And, to load pics you click on the yellow post card icon above, and click Browse This Device, assuming the pics are on the device you are using.

Also, with all that flexing I'm going to guess that your frame may be cracked at the back of the sector box. That's not unusual on these trucks even without the cross member being broken, but with it being broken I'm betting it is likely. But you may not be able to determine if the frame is cracked without pulling the sector box, and even then you'll have to clean things up and look closely.

However, if it is broken badly you will have to determine how valuable the truck is and if you want to fix it. If it is valuable enough to fix then you'll have a couple of methods to hand - have the frame and cross member repaired or move the body to a different frame.

 

Well in this first picture the blue circle is where the cross member is and the green is the hole where the rivet is supposed to be. The yellow is the rivet. There's about a 1" gap between them and about a 3/4" gap between the frame and the cross member
In the second picture it s a hole from a bolt that is on the top of the frame and holds the cross member. The bolt broke and has been broke for a little while as it was well rusted and covered with dirt from a break long ago.
The 3rd picture isn't too good of one but it shows where the frame and bottom of the cross member have been rubbing for an apparent long time.
I checked behind the sector box and all around it. It has been welded for about 3" from the top to the middle. The weld has still held, and I looked all around inside and cleaned it up and there doesn't appear to be a crack a break in the frame anywhere. I asked my uncle who works at a Ford dealership and he said with the right equipment we might could lift the pickup in the air and shove the frame back to the cross member and weld it to the rivet. There shouldn't be any flex among the frame-to cross member as it was riveted before and the other side is tight and doesn't have any flex. We thought we might be able to do that.

 

I think you only have two options; A person who thinks they can fix it by welding it up, either your uncle or someone else, or get another frame.

 

I agree. And I think I'd do the frame swap. Your frame has had a lot of stress and you may have other problems.