CJ38 Frame replacement with a M38 frame?

[jmetz]

Hello all,

I'm trying to figure out what to do about my CJ3a frame (https://jmichelmetz.wordpress.com/2012/12/26/willys-jeep-framing-the-situation/). I have found a possible replacement M38 frame, but I'm having a hard time finding the direct answer to this question:

Can I simply replace my CJ38 frame with an M38? I've found out that the M38 was derived from the CJ38 and that the frame has been reinforced, but I'm not sure if there is anything else that might prevent simply swapping 1:1 (e.g., different mount positions, etc.). I saw one thread in a forum from 2005 which had originally shown a picture of the two of them side by side, but apparently the picture was no longer there and the forum didn't discuss it any further. Much of the other conversations appear to be about going the other way - using a CJ3a to fix a M38.

The repair manual I have doesn't have the M frame types, unfortunately, nor does the restoration book.

Ideas?

Cheers,
J

[1948 Cal Willys Pickup]

Wow J, are you giving up on that frame you just had media blasted? I am guessing on the answer to your question and would guess that the frames would be interchangeable. I would imagine that some things, mostly body panels would have to be modified but most of the stuff underneath would work. Again I am just guessing. The only reason I am guessing is because I was interested recently in an FJ. The FJ uses the same frame if I am not mistaken. I just think back in the day they tried to make different versions of the same vehicle and did it keeping the base the same. This saved them a lot of money in manufacturer costs. Is there anyway to get the two frames next to each other? If not can you take a lot of measurements? Tough decision when you are unsure. Good luck.

[jmetz]

Wow J, are you giving up on that frame you just had media blasted?

No, not giving up on it, just trying to find a backup strategy. I haven't had a chance to take the original to the framers yet (waiting on some parts to arrive first) but I need to accept the possibility that this frame isn't going to be refurbished to a level that will be equally as safe (or reliable) as either getting an after-market frame or possibly replacing it with a better-condition M38 or CJ3a one.


I am guessing on the answer to your question and would guess that the frames would be interchangeable. I would imagine that some things, mostly body panels would have to be modified but most of the stuff underneath would work. Again I am just guessing. The only reason I am guessing is because I was interested recently in an FJ. The FJ uses the same frame if I am not mistaken. I just think back in the day they tried to make different versions of the same vehicle and did it keeping the base the same. This saved them a lot of money in manufacturer costs. Is there anyway to get the two frames next to each other? If not can you take a lot of measurements? Tough decision when you are unsure. Good luck.

I had read that the M38 was based on the 3a, and the M38A1 was the predecessor to the CJ5. After that it gets murky about the similarities, because sometimes people have said that the M38 frame was more akin to the CJ3B, so I'm a bit confused. :(

As far as getting the frames next to each other, that's going to be tough. The M38 is over 2 hours away and carting my existing frame all the way up and back just to take measurements is a huge PITA. I was hoping that I could try to find M38 Frame specs listed somewhere and compare them to the WO original specs - or find someone who may have done it already. :)

I'll post what I can find, though.

[1948 Cal Willys Pickup]

Did a little internet searching. Check out this site (http://www.cj3a.info/cj3a/m38cj3a.html). It has a side by side comparison of the two models. This may answer a lot of your questions.

[Jcmjr1959]

I would think changing frames would be possible , some of the chop shop shows I watch at times anything is possible , the question is what is your long term plan and are you willing to take the time and money and put it on your project....mine is only for fun and I get a thrill out of making something that doesn't work and bring it back to life....not restore because again I don't have they abillity but I make it look great when it is running by at 40 mph... :)

[jmetz]

Did a little internet searching. Check out this site (http://www.cj3a.info/cj3a/m38cj3a.html). It has a side by side comparison of the two models. This may answer a lot of your questions.

Thanks. I did see that, actually. I was a bit concerned about the part where the M38 has "4 holes in the center of the frame for rear pintle hook" (what is a pintle hook btw?) whereas the CJ3A has 6 holes in the frame. I *think* they mean mounting brackets, but I'm not sure.

It's a fantastic list, though. Definitely helpful overall. :)

[jmetz]

I would think changing frames would be possible , some of the chop shop shows I watch at times anything is possible , the question is what is your long term plan and are you willing to take the time and money and put it on your project....mine is only for fun and I get a thrill out of making something that doesn't work and bring it back to life....not restore because again I don't have they abillity but I make it look great when it is running by at 40 mph... :)

This is very true. I've been going back and forth about the pros/cons regarding new frame vs. donor frame vs. fixing what I've got. There are very strong arguments (and emotions) connected with each.

I'm going to take the existing frame to a new repair shop next Wednesday and get a quote. We'll see once that is done, and what the costs might wind up being and how safe I can make the existing frame. If not, I'll have to face some hard facts.

[1948 Cal Willys Pickup]

Thanks. I did see that, actually. I was a bit concerned about the part where the M38 has "4 holes in the center of the frame for rear pintle hook" (what is a pintle hook btw?) whereas the CJ3A has 6 holes in the frame. I *think* they mean mounting brackets, but I'm not sure.

It's a fantastic list, though. Definitely helpful overall. :)

Hey J, a pintle hook is nothing more than a tow hook. In maintenance in the Air Force we have pintle hooks on almost every vehicle. We use them to quickly attach a piece of equipment to a vehicle to relocate expeditiously. They usually look like a loop that opens and closes. They are not typically a ball and receiver like you are probably used to seeing. This allows you to drag something around without needing a receiver. They also aren't typically used to pull heavy items. For most Willys they are attached to the rear crossmember (bumper) directly which is most likely what the holes are that you have. 329