Frame swap 73 to a 77

Does anybody have any experence with upgrading frames? I have a 1973 CJ5 who's frame is a mess. I picked up a frame from a '77 CJ5 that is in excellent shape, comes with power steering, disk brakes and is fully boxed from the factory...I have taken several measurements and it looks like I will have to move most of the body mounts. I was looking for any other issues I will have to deal with?? thanks for any input

 

The '72-75 Jeeps had their own frame design. About the only thing retained from '75 into '76 is the front axle, transfer case and engine. Your suspension parts won't fit (springs, hangers and plates are different). The rear axle won't fit (you'll have to move the spring pads). Do you weld?

If you really want to do it, I expect you could. There will be surprises though.

 

Thanks for the advise, this frame came with front and rear axels, transmision (4spd) and transfer case. would like to swap out the 3pd and use the 4sp out of the '77. I do have a welder and some experience welding. I uderstand the '73 axel (dana) is better than the '77(AMC). So I will probably swap axels. Thanks again

 

The axle ratios won't match, unless they were changed by a PO. The ratios in '73 are 3.73 std, 4.27 opt and in '77 3.54 std, 4.10 opt. The '73 rear axle is indeed much better. You can move the spring pads on the rear axle, and put the disk knuckles from the '77 axle on the '73 axle, and then the ratios will match.

If that's an original wide-ratio Borg-Warner T-18 transmission in the '77, that is a very desirable transmission.

No problem - good luck, and keep us apprised of your progress. :smash: Pics are good...

 

Last time I did a body off I replaced all of the (hat?) channels with 2X2 square stock to correct issues anyway. I would think that a very easy way to deal with body mount locations. Although not stock and it will add some body lift. Not sure if you would want that, many don't. I have done the 44 swap into a late model CJ, that one is a walk in the park with minimal welding and measuring skills needed. I did it with a 110 buzz box in my garage and gently drove it to a location to get the welds burned in better. You will need an angle finder to do it. Swapping out the knuckles also a walk in the park, good time to replace ball joints while you have it apart anyway. Sounds to me like a good opportunity to use the best parts from both to come up with a good combination.

 

Thanks for the advise guys! I like the idea of replacing the hat channels and using the exisiting '77 body mount locations on the frame. also thanks for the advise on the axels, just getting into jeeping and any advise is much appreciated. I picked up the jeep about a year ago as a father son project, unfortunately did not relize the frame had so much damage.

 

i know the story. every time i crawl under mine i see more cracks, weak spots or AWFUL patches from the previous owner...scary. i just about have the parts i need to get the ball rolling on my frame swap.

 

I bought a rolling chassis last month that is suppose to be a 82 CJ-5. I would love to use it except for the model 20 rear axle. The frame gets quite a bit wider at the rear end and I do like that. What bothers me is I've seen several of these factory boxed frames that rust bad right at the front mount for the rear leaf springs. The one I have is starting to go and from what I've heard they tend to rust from the inside out. I saw one that was packed full of sand and obviously had held a lot moisture. You could literally poke your finger through the side of the frame. Not sure if this is a good frame to start another project with or not....

 

You can do it!