BJ42 Frame Swap

[84BJ42]

My frame has a few holes, is thin and has some areas of delamination. I am thinking it is easier to swap frames than to box and patch my current frame. I have a 84 BJ42 and have located a frame from a 80 FJ40. I have read through all of the H55 swap threads into FJ's and am thinking this should be a fairly straight forward swap. I know I will have to change the engine mounts, will I have to make any modifications to my transmission mounts/cross-member? Or can I simply take it out of the BJ and install it in the FJ frame? Is there anything else that is going to complicate things?

[saskdiesel]

When I had a 42 and a 40 frame laying side by side the body mounts on the 42 were different.
Now this was a 75 frame so the later ones may be different.
I have also wondered if anyone has done this swap.

[84BJ42]

I have been looking for an 80+ frame as the body mounts should be the same due to the changes in 79. Thanks

[BreckenridgeCruiser]

Keep in mind the frame has to be from a 8/80 or 1981 model year. If it is an earler '80 frame it will be the same as the earlier models. There were a lot of changes between the 79 and 81 years.

[84BJ42]

Thank's I had seen a reference to 8/80 but didn't know what signifance that had, guess I'll have to go check the VIN number.
Anybody know what kind of issues I might have with cross members etc.

The cruiser is nealy complete except for a rusted out body. Is my assumption correct that the only parts in the frame and drive train that will be of any use would be the frame, suspension and brake parts. The gear ratio will be different, and wasn't there a change in the birfield joints for 84?

Thanks for all the help

[macattack_ga]

I put a '81 BJ42 on an 80 FJ40 frame. we had to cut the motor mounts and spring hangers off the BJ42 frame. the '80 FJ40 uses the narrower springs.
I think we had to use the BJ42 tranny support too. the body fit fine.

[BreckenridgeCruiser]

That's right! Thanks for the reminder. Two major changes on the frame were the change to new body type in 1979. Then they changed the spring hangers in 8/80 to a wider spring eye. Also, the tranny supports may have been different as the 1979 and maybe the 1980 model year had the parking brake at the transfer, not at the rear axle.

[Diescipel]

I can add only one bit of info. The BJ42s with the H55F require a little more room for the 5 spd tranny, so the frame X-member immediately behind the tranny is actually moved back a bit on these frames, which also means the fuel tanks are slightly different in shape. In other words, you may have to move that X-member back on your 80 frame. Luckily, you will have the later fuel tank from your BJ.

I had to have my fuel tank replaced a while ago and got one off a 1980 parts truck, but it would NOT fit. I had Marv Spectre track down a later tank (the part nos. are different) from I believe an 83 FJ40--it seems they didn't want to make two different tanks for the BJs and FJs so the FJs got the new tanks as well.

Note that this is on a stocker BJ42. I would do some careful measurements and you may be able to get around this with putting your motor mounts in the right place.

HTH
B

[84BJ42]

Thanks for all the info, I was afraid I might have to move that cross-member, and didn't really want to get into that. Can't be too picky in Newfoundland, there's not a lot of curisers to pick from, and shipping is the deal breaker. The 80 FJ I'm looking at also has the gas tank. If I shift the motor mounts, and purge the gas tank, I should be able to use it for diesel? I will be getting into drive shaft lengths then.
I think you're right, have to take some careful measurements.

Diescipel, not to get off topic but, I have been following the Parabolic stories and am wondering how you like suspension setup and which shocks you are running.

Thanks