Rear Crossmember Removal / Body Mount Bolts

[aggiecruiser]

I am a newbie. So I am going to just jump right in.....no better way than trial by fire. I hope to post up some pics of my rig later this weekend.

I have a 1979 FJ40. Love it.

I want to install a different bumper. Here in lies the problem. The previous owner WELDED the bumper onto the rear cross member. In my assessment, there is no way to remove the bumper by cutting it off without compromising the strutural integrity of the rear cross member. So here is my root problem. How do I remove the OEM rear cross member that is riveted to the frame with no less than 20 rivets. Eight on the aft face, eight (8) along the bottom face of the bumper, and alas, the four (4) on the top face of the bumper.

I have purchased a replacement rear crossmember, which should be a direct bolt up.

Status so far: I have removed all but two of the rivets on the front face, and the four rivets along the top. Not as bad a job as I thought it would be. But I fear the problem is going to be with the last four along the top. I have NO access to drill them like I did the others. I fear that I am going to have to take the body loose, and shift it forward to get to them.

So, long story short – I have jumped down a rabbit hole, and need some help.

My original problem has spawned itself into another more involved problem….great. I have the body prep'ed to be unboltedfrom the frame, (removed front fenders, removed the tranny access panel, loosened the parking brake attach, disconnected the steering column, anything I forgot?)

How do I get those stinking body bolts loose? It appears that there are (6) total holding the tub to the frame. The middle set is perplexing me. The head of the bolt appears to be a blind application. I can feel it when I put my hand up there, along with a piece of sheet metal? Any body have experience trying to remove these things? Or perhaps, does anybody have a simpler idea on how to remove the four (4) upper rivets holding my rear crossmember onto the frame? In addition, I need to use those same holes for my replacement bolt up, so I alos need to be able to drop the bolt in, and be able to wrench it.


Help!!!!!

 

[dbarrett]

Can you use an angle grinder to remove the underside of the rivets that you can reach. I never drilled out my rivets. I ground the tops or bottoms off then popped them out with an air chisel. Once you remove the bottom-pop the rivet up as far as you can. Then cut the top off with a saws all if you can get it into the gap between the frame and the bumper and the top of the rivet.

 

[idus25]

I ran into the same problem with my 72.

As far as your body problem I am afraid I can't help.

I am lucky enough to have a plasma cutter. I protected the under body and tire with welding aprons and melted them right off. IF you don;t have one maybe your welding house could rent one to you for a few hours.

Good Luck.

 

[Weedhopper]

Body bolts

I 2nd the angle grinder approach. $29.00 at Wal mart. CAREFULLY grind the bolts and rivet heads off and start fresh. You can get REAL good with the grinder if you take your time. You might even save some dental bills at home!

 

[nwtreeoctopus]

I'm currently replacing my rear cross-member because of soul-wrenching rust. You've got to find yourself an air-chisel, they make the job so much easier. I'm not sure if this will be helpful to you, but Coolerman sent me a link to step by step instructions (with pictures) for replacing the rear x-member. Maybe something useful in there for you.

http://tinyurl.com/2q9jn9

 

[aggiecruiser]

Do you have the body off the crossmember you are replacing? I have very little access to the rivets in the axis direction. Once i get the head or tail knocked off, (cut off, air chiseld off, etc.) I don't know how I will punch them out if I cant get a punch in line with the rivet.

granted, i am not a fabricator, and the rivets in this bumper have been the first i have ever removed before.

so step me through it, once i get the head off, how do i extract the shaft of the rivet?

I don't WANT to remove the body, but I see it as my only option for the four remaining rivets on top.

BTW, i want to thank everyone for their suggestions, i really appreciate the help, and hope to return the favor sometime. the barter system works for me!!!!

 

[Fiberglass40]

I had the rear gussets and crossmember removed and fabricated awesome replacements from a local fabricator. I had a friend remove the rusted out gussets and crossmember. He took the heads off the rivets with an electric chipping hammer type of tool and maybe an angle grinder as well. It did not seem to take him more than half a day. The chipping tool was a real cheapo one, Chicago Pneumatic, from Harbor Freight Tools. You know, made in China and bizzarely cheap compared to normal tools of that type. But sometimes the cheap ones are worth it for a job like this, and if they bust or burn out I take them back right away and it is no loss. I don't know if you have a local metal fabricator, but mine made the pieces as a favor. It saved me HUNDREDS compared to what I have seen a Cruiser shop sell them for.

 

[miker]

Coolerman's write-up shows this but you have not mentioned it so I thought I'd point out that you also have a couple of welds to grind/cut loose to remove the rear crossmember unless you plan to remove the rear spring shackle hangers and triangular supports with the rear crossmember as one unit.

For the body bolts that are located in the "pocket" of the mid-body supports on the '79 and newer tubs, there is a locking tab that is supposed to hold the bolt from turning in that pocket however, it doesn't take much force to spin it past the "lock" especially when you are dealing with rust. For mine, I was able to reach in the pocket with a wrench and hold the bolt head. Use lots of penetating oil on the threads to help free the nut. In one case, I was also able to wedge a screwdriver in the pocket to keep the bolt from turning. The other option is to cut the bolt and replace it when you reassemble.

 

[Degnol]

Look inside the tub for the heads of the middle two bolts. A '79 may be different, but a look is cheap

Ed