TJ vs LJ: a few thoughts

[mrblaine]

I haven't had good luck doing that. My strike pin is probably out of adjustment and I know my hinges don't have a lot of life left.

You need a new tub anyway.

 

[Superjay5]

When I did have a CJ many moons ago, I remember one time I got stuck on a hill all twisted up, I had to open my tailgate to get some gear, was hard to get the tailgate to open. It was impossible to shut! The tailgate opening was being twisted in a way that the opening was to small to now close the tailgate. Wasn’t until I got to flatter ground that I could shut it. I know this was a CJ, but that was my first experience on how much the tub and that area could move… just an observation.

Take a close look at the strike pin. There is a reason it has that big washer on the end of it which just sneaks by the side of the latch claws. Also why the strike mount on the tub is slightly angled, fairly robust and mounts to the strongest part of the inner fender. They designed it to close and lock the gate in with as little lateral movement as possible.

So guys switching to a CJ tailgate on a TJ could also run into issues with those spot welds failing? Since they lose the latching mechanism of a TJ, as the CJ latching is way less robust and doesn’t tie the tailgate in like a TJ.

 

[Mike_H]

You need a new tub anyway.

I hope not...the tub is clean. Frame...not so much. I really just need to cut my losses at this point and get something more suited to what I want to build...

 

[mrblaine]

So guys switching to a CJ tailgate on a TJ could also run into issues with those spot welds failing? Since they lose the latching mechanism of a TJ, as the CJ latching is way less robust and doesn’t tie the tailgate in like a TJ.

Not sure. All I know is I have seen several instances of those spot welds broken loose and even with a tailgate if you dig it up in Josh's thread.

 

[wheelman2925]

If you want to see a TJ tear itself up in a certain area, run one without a tailgate. The taillight panels will separate from the torque box above the rear crossmember in short order. Oddly, there are only a few spot welds that tie the rear of the tub on either side of the tailgate to that torque box on each side. Even with the rear cage bolted down correctly, those spot welds will rip out of the sheet metal in a hurry.

Given what is involved in building a TJ-6, I was very surprised at the responses. I expected much better.

Perhaps it's just some people copying what you've developed and understand while they are just following a trodden trail. You then offer a furtherance of the knowledge and get questioned because change is scary and bad.

Had no idea the tailgate played such a crucial role in structure, I just rely on it not to let the replacement parts/ garbage fall out before I install them.

 

[mrblaine]

Perhaps it's just some people copying what you've developed and understand while they are just following a trodden trail. You then offer a furtherance of the knowledge and get questioned because change is scary and bad.

I asked if those who had used the standard accepted method for building a TJ-6 had built and installed a 4th body mount behind the original 3 since the span is now 15" longer. Why did you or why didn't you do so?

The vast majority of the answers had nothing to do with the conventional build plan.

I used an LJ frame and didn't see the need. Well, no shit since the factory didn't either but that was not the QUESTION being asked.

Fortunately a friend came to my rescue with something I had not seen before that perfectly justified my logic in adding the 4th mount. A pic of the Egyptian extended wheelbase TJ frame was the perfect answer.

And mine.

 

[wheelman2925]

Nice find. Please forgive my inexperience, but in looking at both pics, it appears you raised the body mounts negating the need for body lift? If so, makes sense to me.

I imagine, due to inherent frame flex, that adding a body mount not only strengthens the whole assembly, it lessens frames sag or distortion also preventing tub damage.

I've only begun to look into a TJ-6 but I like what I'm seeing as far as effort to benefit ratio. The 108" would suggest a 40" tire at 19 belly height? Just wondering at this point.

 

[mrblaine]

Nice find. Please forgive my inexperience, but in looking at both pics, it appears you raised the body mounts negating the need for body lift? If so, makes sense to me.

Yes, we've been doing that since at least 2000 long before there were kits. In fact, the ones I did on Jon's rig for Viking Offroad and Winchline.com were the ones that Genright used to build theirs.

I imagine, due to inherent frame flex, that adding a body mount not only strengthens the whole assembly, it lessens frames sag or distortion also preventing tub damage.

No idea I just figured if the factory used a certain spacing and I exceeded that, I should fix it.

I've only begun to look into a TJ-6 but I like what I'm seeing as far as effort to benefit ratio. The 108" would suggest a 40" tire at 19 belly height? Just wondering at this point.

If you like nice clean work and want something that has to be stared at a bit to figure out what has been done, it is a buttload of work. If you have low standards, it can be done much quicker.

I have had lots of folks look at mine. The vast majority of them don't even notice it is 15" longer, has a TJ overhang at the rear tires, or that there is a lot of room between the rear of the door opening and the front of the rear flare. Nothing really stands out as something to give them a place to start noticing. I hope the same is true after paint.

Belly height is a bit low for that wheelbase for us.

 

[wheelman2925]

Yes, we've been doing that since at least 2000 long before there were kits. In fact, the ones I did on Jon's rig for Viking Offroad and Winchline.com were the ones that Genright used to build theirs.

No idea I just figured if the factory used a certain spacing and I exceeded that, I should fix it.

If you like nice clean work and want something that has to be stared at a bit to figure out what has been done, it is a buttload of work. If you have low standards, it can be done much quicker.

I have had lots of folks look at mine. The vast majority of them don't even notice it is 15" longer, has a TJ overhang at the rear tires, or that there is a lot of room between the rear of the door opening and the front of the rear flare. Nothing really stands out as something to give them a place to start noticing. I hope the same is true after paint.

Belly height is a bit low for that wheelbase for us.

Thanks for the detailed reply. I am beginning to see just how much planning and effort go into making it look like nothing was done. I'd love to see Blaine built TJ-6 in action next to a Blaine built 35 tire TJ/LJ even if just to see the different abilities of each. Thanks again.