- Thread starter
- #121
Rear Shock Posts done. Instead of adding posts to the u-bolt skid plates I opted to cut and bend the existing posts.
72 FJ40 Chevota Build
- Thread starter Tokamak
- Start date
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I've scanned through your build so far, and I must say Mr. Tokamak certainly has his act together, great craftsmanship. I do have 3 comments and/or concerns though:
(1) You could have built a second story in your glove box for ECU mounting, up off the floor about 4", wiring could have routed over the top of the drivers side wall,then you'd still have glove box space.
(2) I have not seen that you have re-installed a rear torque tube behind the transfer-case. You have a hot riveted frame, flexes like crazy, and then the torque tube is what returns the frame back to original spec (squares up the frame) after a good frame flexing in off road terrain.
(3) It appears to me that your front cage connector tube that routes back to the rear bar is far too close to the drivers head, appears it would be a head banger when bouncing in off road terrain???
(1) You could have built a second story in your glove box for ECU mounting, up off the floor about 4", wiring could have routed over the top of the drivers side wall,then you'd still have glove box space.
(2) I have not seen that you have re-installed a rear torque tube behind the transfer-case. You have a hot riveted frame, flexes like crazy, and then the torque tube is what returns the frame back to original spec (squares up the frame) after a good frame flexing in off road terrain.
(3) It appears to me that your front cage connector tube that routes back to the rear bar is far too close to the drivers head, appears it would be a head banger when bouncing in off road terrain???
- Thread starter
- #123
Jim,
Thanks for the complement and the analysis. In hind sight the ECM may have been better at the top of the glove box. I had planned on laying a shelf flush with hinge line to cover the ECM.
I looked at pictures of Jackson Cages and thought I assembled it correctly (no instructions provided). Sitting in the seat the bars do feel a little close when you bounce side to side. An option will be to lower the seat if its a problem. Thanks for being on the look out for skull fracture potentials.
The last item is the torque tube. It's been in the back of my mind as to what its for so I can replace it with a structural equivalent. The curved torque tube (the missing one) must work in conjunction with the straight tube (further back) to maintain some stability to the frame. There are 3 things I can think of that are being prevented. 1) prevents the frame from spreading wider or narrowing. 2) Controls racking of the frame right/left front to back. 3) Controls frame twist between the two tubes.
I would guess in order of most to least effect 3, 1, then 2. I was planning on a skid plate under the Transmission and Transfer Case to deal with most of it. I also did a 1" body lift using thin wall square tube across the frame in 3 places. I can up the wall thickness and weld them in once I know its the correct thing to do. I'm still up in the air about welding or floating the square tube (in the body mounts) across the frame. I know the frame needs to flex and don't want weld in stiffeners that tend to crack welds.
Thanks for the complement and the analysis. In hind sight the ECM may have been better at the top of the glove box. I had planned on laying a shelf flush with hinge line to cover the ECM.
I looked at pictures of Jackson Cages and thought I assembled it correctly (no instructions provided). Sitting in the seat the bars do feel a little close when you bounce side to side. An option will be to lower the seat if its a problem. Thanks for being on the look out for skull fracture potentials.
The last item is the torque tube. It's been in the back of my mind as to what its for so I can replace it with a structural equivalent. The curved torque tube (the missing one) must work in conjunction with the straight tube (further back) to maintain some stability to the frame. There are 3 things I can think of that are being prevented. 1) prevents the frame from spreading wider or narrowing. 2) Controls racking of the frame right/left front to back. 3) Controls frame twist between the two tubes.
I would guess in order of most to least effect 3, 1, then 2. I was planning on a skid plate under the Transmission and Transfer Case to deal with most of it. I also did a 1" body lift using thin wall square tube across the frame in 3 places. I can up the wall thickness and weld them in once I know its the correct thing to do. I'm still up in the air about welding or floating the square tube (in the body mounts) across the frame. I know the frame needs to flex and don't want weld in stiffeners that tend to crack welds.
- Thread starter
- #124
Here is something on the tubular cross member. For lack of a better solution I think I'll find a way to install it behind the existing TC output.
Bolt in Torque Tube?
Bolt in Torque Tube?
The problem with body lift kits is over time they tend to crack the sheet metal floor all around the mount. This is usually not a problem until you get up into 2" and 3" body spacer blocks (which exaggerate frame movements dramatically). I'd do the 1"ers, then just use larger/thicker washers at the floor sheet metal.
- Thread starter
- #126
Okay, I'm on board with installing the tube back on the frame. The two links below talk about frame cracks from the frame twisting due to the torque between the rear end and the drive train when the tube is removed. Thanks for bringing to my attention Jim.
https://forum.ih8mud.com/threads/frame-strength-removal-of-cross-bar-for-sbc-tranny-combo.827217/#post-9498973
https://forum.ih8mud.com/threads/torque-tube-suggestions.546848/
https://forum.ih8mud.com/threads/frame-strength-removal-of-cross-bar-for-sbc-tranny-combo.827217/#post-9498973
https://forum.ih8mud.com/threads/torque-tube-suggestions.546848/
- Thread starter
- #127
Worked on my gauge plate last night.
Don't know why its upside down??
Don't know why its upside down??
- Thread starter
- #128
I ran a simple stress analysis on a simulated frame. The tubes are taking all the stress. Trying alternatives to the tube and none are equivalent so far.
The left side is held steady (green Arrows) and then apply up and down force on the right (pink Arrows)
The left side is held steady (green Arrows) and then apply up and down force on the right (pink Arrows)
- Thread starter
- #129
With all parameters remaining the same a Cross Bar configuration reduces the total deflection by 1 mm. and reduces the stress on the tubes. Now its a matter of finding out how small the cross tubes can be without more deflection than the original.
The previous picture was Stress on the components. these two pictures compare deformation (deflection).
The previous picture was Stress on the components. these two pictures compare deformation (deflection).
- Joined
- Jan 6, 2012
- Threads
- 341
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- 10,925
For as nice of a build as you are doing here, I would do something other than the hell creek suspension. Its going to ride like a tank. Or you could try messing with the shackle angle with those springs and that would help those springs have a softer ride.
- Thread starter
- #131
When I bought the Hell Creeks they were supposed the nicest springs on the market. Its all subjective I suppose. There has been no load on the springs so far. Once it starts rolling I'll throw 2 or 300 lbs in the back and soften them up. Once they soften up I can adjust the shackles. Right now the rear is better than an inch higher than the front. Not sure what it will be with a full tank of gas.
Just Ordered a "Torque-Tube" from 4PlusProducts.com
Just a note on firewall connectors: DO NOT attempt to use the GM OEM firewall connectors, they are almost impossible to use because the wires/wire colors (a) are not a straight through matchup, and (b) often change colors at the connector. If anyone has used one with success, they are blessed!!!!! Easiest to use the one piece harness that goes through the firewall with a rubber grommet.
- Thread starter
- #136
Yep Amazon.
Amazon.com: 22 Position Delphi Weather Pack Connector Kit 12 to 20 AWG w/Locks: Automotive
The ECU harness from the donor truck passed through the firewall without a connector. A plastic clamp filled with hot glue was what they used.
- Thread starter
- #138
Finished off the most of the work on the half doors.
Yes, I didn't see it on the website either. I had to email Dave. Look for the email address in the ordering section of the site.
Not sure why it wasn't listed. Maybe they don't sell enough.
- Thread starter
- #140
On a more serious note. The rear diff was tilted up toward the transfer case output shaft. The single Cardan joint has the least vibration when straight.
The fill plug on the diff is now a lot lower than original. The original fill plug location allowed filling till the oil level would touch the bottom of the pinion bearing. I added a fill plug that would allow filling to the same location on the pinion bearing. Problem is. . . I would need 6 quarts of oil, and the axles will be completely submerged. I filled it with 3 quarts (stock amount) and am hoping that the ring gear will throw the oil up to the pinion.
Any thoughts or experience on this?
The fill plug on the diff is now a lot lower than original. The original fill plug location allowed filling till the oil level would touch the bottom of the pinion bearing. I added a fill plug that would allow filling to the same location on the pinion bearing. Problem is. . . I would need 6 quarts of oil, and the axles will be completely submerged. I filled it with 3 quarts (stock amount) and am hoping that the ring gear will throw the oil up to the pinion.
Any thoughts or experience on this?