Sab-a-dab-a-doo! The back-country LJ build has officially started

Depending on how you want it to look, your bigger problem is the radii for the top corners and bottom corners of the frame tube do not match. The lower tends to be a larger radius and at times the tube resembles a very elongated letter D due to the compression of the top face and the stretch of the lower when they bend it. It is clearly not a mandrel bend.

Typically tube is very consistent so you'll have to fill and metal finish to get it tolerable looking.
1715867326715.png
 
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sab said:
Today's Question Number 2:

Besides the amount of work involved, what's bad about cutting off the rear crossmember (the one right behind the bumper), and welding my Dirtworks bumper in it's place, effectively pulling the rear in a couple inches or so? Here's a picture:

View attachment 527319

I realize that I'll lose the ability to quickly change to a different bumper and that I'll have to open the back of the tube bumper and add a platform for the rear body mount attachment, but the fact that I don't see much discussion about such a mod makes me think that it would have already been done if it was a good idea...
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I don't do it that way because a wreck that bends the bumper is a pain in the ass. If I do add a weld in cross member in place of a bumper, I make it heavy enough that casual bumps won't hurt it and anything that hurts it will ruin the rig. That logic may not apply to your situation.
 
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sab said:
OK, I'm not understanding this, after thinking, measuring, and drawing late last night. If I make the vertical cut right in front of the LJ's rear gas tank mount cross member, move the now-separated rear of the frame up 1.25", make a horizontal cut 1.25" up to what's left of the rear frame horns, and take that piece just cut off and put it in the gap at the top of the front of this junction, it doesn't work because the radius is inverted:
View attachment 527295

What am I not getting? On another note, I think I found a source for some 2.5" x 5" x .188" tubing to use for that piece.
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Might want to see all the photos and explanations here .. two ways to do the rear raise and how Blaine does it makes it look like it was always that way.

https://wranglertjforum.com/threads/raising-rear-frame.47735/
 
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mrblaine said:
Fucking engineers.
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Guilty!

An angled cut and dealing with the weird radius like that is too inelegant for me. I'll complicate the crap out of it with the intent to make it look better, and then not succeed at making it look better. It's the engineer's way. :ROFLMAO:

mrblaine said:
Depending on how you want it to look, your bigger problem is the radii for the top corners and bottom corners of the frame tube do not match.
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Yes, the top radius is 8" and the bottom is 12". I'm working on a plan similar to what Good Hope posted last spring (I told you I'd complicate the crap out of it):
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mrblaine said:
The lower tends to be a larger radius and at times the tube resembles a very elongated letter D due to the compression of the top face and the stretch of the lower when they bend it. It is clearly not a mandrel bend.
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I noticed that last night while looking at it. I was surprised to see that it was not a mandrel bend.

mrblaine said:
Typically tube is very consistent so you'll have to fill and metal finish to get it tolerable looking.
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That's just part of my "complicating the crap out of it!" I've had to work on my patience over the decades because I don't have the natural patience to go with my engineer's "perfectionism" (not really the right word, but close enough).
 
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mrblaine said:
I have short sections of frame and 2.5 x 4" x .188 wall if you need some.
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That would be awesome - as usual, much appreciated, Mr. Blaine! I'll PM you once I have a plan worked out.
 
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mrblaine said:
I don't do it that way because a wreck that bends the bumper is a pain in the ass. If I do add a weld in cross member in place of a bumper, I make it heavy enough that casual bumps won't hurt it and anything that hurts it will ruin the rig. That logic may not apply to your situation.
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I certainly understand that logic, and it follows my thinking as to the main reason NOT to do it. My use case is that I likely won't do a lot of rock crawling, but I won't do zero rock crawling. Still mulling this one over...
 
psrivats said:
Might want to see all the photos and explanations here .. two ways to do the rear raise and how Blaine does it makes it look like it was always that way.

https://wranglertjforum.com/threads/raising-rear-frame.47735/
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Thanks, psrivats! That's one of the threads I've studied quite extensively, along with these:

https://wranglertjforum.com/threads/how-to-raise-the-rear-frame-and-eliminate-your-butt-crack.53656/
https://wranglertjforum.com/threads/rear-frame-mod.68906/

In those three threads, I've found these methods (don't know if credit is given to the right forum users, so I apologize if I'm not giving due credit):
  1. Mr. Blaine's method
  2. jjvw's method (cutting a wedge)
  3. Good Hope's method (lots of fab and welding)
With those in mind, I'm doing some CAD work to think it through for my solution.
 
sab said:
Today's Question Number 2:

Besides the amount of work involved, what's bad about cutting off the rear crossmember (the one right behind the bumper)
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Now that I have a few more minutes, it is time to throw a few rocks. You have no crossmember behind the bumper, it is in FRONT of the bumper.
sab said:
, and welding my Dirtworks bumper in it's place, effectively pulling the rear in a couple inches or so? Here's a picture:

View attachment 527319

I realize that I'll lose the ability to quickly change to a different bumper and that I'll have to open the back of the tube bumper and add a platform for the rear body mount attachment, but the fact that I don't see much discussion about such a mod makes me think that it would have already been done if it was a good idea...
Click to expand...
If you need some good washers, post up the bolt diameters and I'll send you some to replace that crap you have now. If those are split locks under the nuts, that's sad. If they aren't, then who uses a washer that small with a slot that size? The thin washers deforming into the slots are almost as bad.

Stop with the bumper jewelry. That stuff belongs in your recovery gear bag to protect it from loss and the elements. If you think you'll need it in a hurry as the reason to leave it there, stuff one inside your recovery gloves and store it beside the driver's seat. Special folks have one on each side.
 
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mrblaine said:
Now that I have a few more minutes, it is time to throw a few rocks. You have no crossmember behind the bumper, it is in FRONT of the bumper.
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Touché - that rock hit me square in the forehead! Volley coming back...

mrblaine said:
If you need some good washers, post up the bolt diameters and I'll send you some to replace that crap you have now. If those are split locks under the nuts, that's sad. If they aren't, then who uses a washer that small with a slot that size? The thin washers deforming into the slots are almost as bad.
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I knew you'd call me on that. No, they're not split washers. It's either what was supplied with the brackets or whatever I had in my fastener pile. I wasn't concerned because this LJ hasn't been driven in 18 months because it's in build, not use, status. When I installed the brackets, I was already contemplating doing something completely different back there, so it's temporary. Welding was what I was thinking long-term. I do like to complicate things, but I'm not going to acquire proper hardware for something temporary.

mrblaine said:
The thin washers deforming into the slots are almost as bad.
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Again - it was temporary. Better a deformed POS washer than the corners of a hex bolt head cutting into the frame was my thinking...

mrblaine said:
Stop with the bumper jewelry.
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I know that you know me better than that. My vanity-influenced vehicle decisions are almost non-existent. My daily driver (the 400,000 mile POS Subaru I've posted about here) is by far the worst-looking vehicle in the lot. Granted, this LJ is my bucket-list vehicle so I do care more about how it looks, but only to my eye.

mrblaine said:
That stuff belongs in your recovery gear bag to protect it from ...the elements.
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Hey, aren't you the feller that brags about living where rust always rests? Me, too.

mrblaine said:
If you think you'll need it in a hurry as the reason to leave it there, stuff one inside your recovery gloves and store it beside the driver's seat. Special folks have one on each side.
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Bingo - that's why they are there. I'll consider your advice on the alternative.

Thanks, Mr. Blaine - again, I appreciate the time you spend dispensing your wisdom!
 
sab said:
Hey, aren't you the feller that brags about living where rust always rests? Me, too.
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Yes, but, the exception is we get rain while we are on dirt which makes mud which then gets where we don't want it to and corroded pins suck. Not to mention, if they are tight enough to not fall off, you need a tool to get them loose. I have helped every rig owner that has graced my driveway with that little problem by removing the pins, adding some 609 to the threads and screwing them back in so they don't fall off. They are also practically non removeable at that point, but they never fall off.
sab said:
Bingo - that's why they are there. I'll consider your advice on the alternative.

Thanks, Mr. Blaine - again, I appreciate the time you spend dispensing your wisdom!
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Not wisdom, just entertaining myself by picking on smart folks who neither need or deserve it which is where the fun is.
 
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mrblaine said:
I have helped every rig owner that has graced my driveway with that little problem by removing the pins, adding some 609 to the threads and screwing them back in so they don't fall off. They are also practically non removeable at that point, but they never fall off.
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609, as in the green bearing retainer goop? I've never used that one on threads, but I have used it when tolerances for a bearing race and it's mating socket ID are wonky. Are you using it due to the size of the threads and the associated large gap between internal and external?
 
sab said:
609, as in the green bearing retainer goop? I've never used that one on threads, but I have used it when tolerances for a bearing race and it's mating socket ID are wonky. Are you using it due to the size of the threads and the associated large gap between internal and external?
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I assumed he does it in order to teach a lesson rather than any other reason.
 
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Apparition said:
I assumed he does it in order to teach a lesson rather than any other reason.
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Yeah, I got that, but wondering why 609. My choice would be 277. It's what we always used on big fasteners we didn't want coming apart. I'm wondering if I need another lesson today...
 
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mrblaine said:
Depending on how you want it to look, your bigger problem is the radii for the top corners and bottom corners of the frame tube do not match.
Click to expand...
sab said:
Yes, the top radius is 8" and the bottom is 12".
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Just realized my response doesn't make sense. I knew you were talking about the smaller radii at the corners of the rectangular frame tube varying from the frame rail bending process (no mandrel used), but then my response was about keeping the production frame rail bend radii (8" for inside bend radius/12" for the outside bend radius) in the final mod, which is why I posted the picture that Good Hope posted. I think you understood my mish-mash response, though.
 
sab said:
Yeah, I got that, but wondering why 609. My choice would be 277. It's what we always used on big fasteners we didn't want coming apart. I'm wondering if I need another lesson today...
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I use 609 on the rod end threads for all the cylinders we cut them down for in our hydro assist due to not having enough room for a jam nut. They never come loose, ever. Also stops you from losing your bumper jewelry.
 
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mrblaine said:
I use 609 on the rod end threads for all the cylinders we cut them down for in our hydro assist due to not having enough room for a jam nut. They never come loose, ever. Also stops you from losing your bumper jewelry.
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I could tell you a story of 609 saving some hard-to-come-by VR 1000 engine cases that were desperately needed to keep us running one weekend...
 
mrblaine said:
...bumper jewelry.
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If I do decide to make the bumper a permanent part of the frame, I may mod those attachment points so my trusty BMB soft shackles can be used without the bumper jewelry. What's the minimum radius for the soft shackles? I'm guessing in the 3/4" - 1" range based on connections commonly used, but I've not researched it, yet. Do the rope manufacturers have standards?
 
sab said:
If I do decide to make the bumper a permanent part of the frame, I may mod those attachment points so my trusty BMB soft shackles can be used without the bumper jewelry. What's the minimum radius for the soft shackles? I'm guessing in the 3/4" - 1" range based on connections commonly used, but I've not researched it, yet. Do the rope manufacturers have standards?
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Can the minimum bend radius be required to be larger than the diameter of the line under the knot? ;)
 
mrblaine said:
Can the minimum bend radius be required to be larger than the diameter of the line under the knot? ;)
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Obviously knot (pun intended). Doh!

It's funny, I was thinking 3/4" to 1" thinking about the safety thimble end, and didn't even think about the connection on itself. Sometimes you're the windshield, today I'm the bug.
 
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