Broken bolts on CJ7 transmission crossmember

[peterblesi]

On the driver side of the transmission crossmember on my 79 CJ7, there are 3 bolts holding it to the frame. 2 of the bolts are broken off (I'm assuming to nuts welded inside the frame).

I'd like to repair the bolts without removing the crossmember.

Anyone have suggestions / experience repairing without taking the entire jeep apart and without using a welder ?

I'm thinking of these options: (1) drilling through the center of the broken bolt and retapping (2) drilling for the next larger bolt and tapping (3) drilling through the broken bolt, continuing the hole through the top of frame and putting in a through bolt with a nut/washer on top of the frame.

Any thoughts ?

 

[54cj3b]

79 pretty sure are just nuts and bolts, get a few grade 8s and be on your way

 

[Saddle Tramp]

On the driver side of the transmission crossmember on my 79 CJ7, there are 3 bolts holding it to the frame. 2 of the bolts are broken off (I'm assuming to nuts welded inside the frame).

I'd like to repair the bolts without removing the crossmember.

Anyone have suggestions / experience repairing without taking the entire jeep apart and without using a welder ?

I'm thinking of these options: (1) drilling through the center of the broken bolt and retapping (2) drilling for the next larger bolt and tapping (3) drilling through the broken bolt, continuing the hole through the top of frame and putting in a through bolt with a nut/washer on top of the frame.

Any thoughts ?

There are nuts inside the frame that are tack welded to the inside of the frame before the two halves of the frame were welded together. If your bolts are broken off and not turning freely you are ahead of the game; it is when the tack welds on the nuts break free that you have to open the frame to re-secure the nuts or add a second nut to tighten the bolt. Access is best done with a hole saw.

If the bolts are broken off then the bolts are rusted to the nut. When faces with this problem I drill out the broken bolt, re-tap the hole, and pop in a fresh bolt. The new bolt can be smaller, equal, or larger than the original depending upon what you have to work with. I also always upgrade to a grade 8 bolt. No need to remove the cross member/skid plate that way either.

 

[cweed]

I have had the same problem on a couple of my CJ's and one recently on my YJ. I made a "C" channel that fit around my frames, drilled large enough holes for a 1/2-13 nut to fit in the frame channel, welded nuts to the inside of the "C" channel and through bolted the channel to the frame. That way if I ever have a problem I can repair it. If you don't want to remove the cross member the best bet is to drill through the old bolt with three different diameter bits, smaller to larger and re-tap the threads.