Misc. transmission skid plate questions

[Larry4123]

Hello,

I have a '79 CJ5 I recently purchased. I've been slowly cleaning her up to get her on the road. I've changed engine oil, flushed and changed radiator fluid (with new thermostat and water pump) and drained/flushed/filled differentials. My next task was to drain/refill the transmission and transfer case and put a new exhaust on. To this I plan to drop the transmission skid plate. There is a lot of mud caked in there and my CJ5 has a catalytic converter I was planning to replace while I've got it apart.

The skid plate has 3 bolts holding it to each side of the frame rails. There are 2 bolts in the center that appear to go into a transmission mount in the middle of the skid plate and bolt several inches off center (to the driver's side) that go to up through the plate and has 2 rubber bushings. This bolt is currently missing a nut so it just hang there, loose.

Several questions:

What is this bolt that is off center (currently with no nut, see pictures)?

To drop the skid plate. I should have a jack support the weight of the transmission/transfer case when I remove the skid plate? As the transfer case is entirely behind the skid plate, is one jack on the transmission enough to support it?

Bigger problem. The 6 bolts (3 on either side) that hold the skid plate to the frame. The first one I tried to loosen, groaned and then started to spin freely. I'm assuming the bolt that was welded to the inside of the frame broke loose and the bolt/nut is spinning. I assume I have to cut the bolt to remove the skid plate with the other 5 bolts removed. Is there a way to repair this without cutting an access hole in the side of the frame and welding a new bolt in? (This is something I can not do!)

Any suggestions to reduce the risk of breaking another nut free from the frame when I try to remove the bolts?

Pictures of center of skid plate with one bolt without the nut and a picture above skid plate.
Picture top side of skid plate with mud packed in
Picture of bolts attaching skid plate to frame, 2 of 3 blots in picture. Front/passenger side is bolt that spins freely.

Any help appreciated.

Thanks,

Larry4123

?

 

[BrockGrimes]

A jack or jack stand under the trans will hold it. I've dropped the trans, t-case, and plate all as one unit, no biggie.
T-150, 20 combo

 

[Larry4123]

Yes, I can place a jack under transmission to support and remove the skid plate. My biggest concern now is, the one bolt that spins freely. Feels like the nut inside the frame has broken loose. If I cut that bolt and remove the other 5 bolts plus the transmission mount in the center, how can I repair/replace the bolt I cut. Do I have to cut a window in the frame and weld a nut back in place? Would a "jack nut" or something like that, work (be strong enough)? I haven't tried to loosen the other 5 bolts for fear they may also break off, until I have a plan to repair any more if needed.

 

[TSB8C]

On a previous CJ5 ('77 I seem to recall) I had the same issue of a broken loose and free spinning captive nut holding one of the skid plate bolts. I also broke off two others when removing the remaining ones. In determining a course of action, I noticed that the skid plate is wider than the frame rails and has an inch or so of overhang on either side. So I welded some angle iron to the frame rails on each side facing downward so as to provide a flat surface sticking out from the frame rails. I then drilled new holes in the skid plate and matching holes in the angle iron to put new bolts into with lock washers and nuts on the other side. This avoided ever having to deal with the captive nuts in the frame ever again. Sorry, no pics. This was years ago.

 

[jammer1]

Depends where the bolt is. I popped the speed nut out leaving a hole in the frame. I cut a piece of 1/8" piece of metal that can lay in the bottom of the frame. Drilled a hole in the metal to match the hole in the frame. Weld the nut to the metal and feed into the frame. Metal holds the nut in place. Now you can bolt the skid plate on and be able to remove the bolt if needed. Behind the skid plate on the side of the frame was a oval shaped hole that you can fit the metal through.

 

[Larry4123]

Thanks for those thoughts. Has anyone used a jack nut or rivet nut to "rethread" the hole for the bolt? May need to drill existing hole a slight bit bigger for sleeve to fit into frame. I've never used one of these nuts so not sure how reliable they are or how much weight they will hold.

 

[jammer1]

https://www.cj-8.com/threads/meet-red-my-81-restomod-build.47006/page-16#post-426913 some info.