Fiberglass tub substructure

Hello. My CJ has the fiberglass tub. Upon inspection I saw that there was a little rot in the "frame" of the bottom of the tub where it mounts to the actual frame of the jeep. The PO also hacked some of the forward mounts. I plan on taking the tub off within the next year. Can anyone tell me about the metal structure under the tub, how I could replace/repair it, and how the best way to mount it to the frame? Thanks.

 

if i understand you correct.. the inner structure of a fiberglass tub at the mounts is wood.. i know they sell fiberglass tub mounting kits from 4wd.. at least for the later cj's

 

Hey halflifesw,

I too have a fiberglass tub. I'm afraid I can't help you with the "frame rot", but I may be able to help with your front mounts. My fiberglass tub is a 55-71 replica and it sits on a 1983 CJ-5 chassis. Because of the year difference the tub did not line up with the front mounts (the firewall went over the mounts but angled in toward the front seats). I had to make a plate if you will, that came straight down my firewall to my mount then 90 degree to under my seat (made one for both sides). I just bolted the top part to the firewall and the bottom part using my front seat bolts! Worked like a charm and I actually welded my clutch bracket (pivot?) to the plate.

So is what I made (the plates) kind of what your talking about that is on the bottom of your tub that is rotted?

Or did I just confuse everyone including myself?

Let me know and I will try to get some pics on here of my setup concerning the plates and mounts..

~Boodie R)

 

From what I understand, fiberglass tubs start out with a plywood substructure and then have some element of reinforcement added in the mounting areas and firewall. What they use for reinforcement varies by manufacturer, but in my case, they used kevlar and the plywood is marine grade. I believe that 4WD hardware uses a metal plate in the firewall, but I know Shell Valley doesn't. Hth.

 

I'll try to get some pics in the next few days for everyone to comment on. digi camera will be out camping for the weekend

 

I had a fiberglass tub that I bought from JCW on a CJ-7. It had no Kevlar or other reinforcement, only wood. My solution for strengthening it was to add some custom metal brackets that spread the weight/torque over a larger surface area, and then I ran the body mount bolts through those. I just used heavy sheet metal that I cut and shaped with grinders. I don't recall the gauge of the metal - sorry.

Some of the mounts I made were just squares with holes in the right places, while others - at the rear cross member - were bent at 90* to run up the back of the tub behind the tail lights (this also helps ground the lights to the frame). The only drawback with that approach is that you would have at least two bolt heads showing on each side of the tailgate area. I hope this helps.

 

thanks for everyone's help. I'm still working on getting the pictures to show you what I have

 

oh, another question I had was where should the roll bar be bolted to? It appears that mine is just bolted to the tub????

 

Where bolts go through the plywood core put some sealant on the bolts to prevent moisture from entering the core.