Jeep Nasty
Active member
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- Location
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Back story is I had no intention of bobbing this. I did some climbing over 4-5 foot tall boulders in my back yard and blew out 8 of the 12 Control arm bushings in the rear tandem axle assembly.
When I looked at all the work and cost that was involved I decided to just go ahead and Bob it to eliminate the control arm bushings altogether.
I used a set of mrap springs that I purchased in the classifieds and this is where I'm at so far.
I also decided to swap in an axle with a Detroit locker in it.
before picture
Work begins.
I also took on this task in my driveway with limited tools at my disposal. I am getting very good at borrowing what I need.
I put my 5 ton trailer behind the crew cab unbolted the bed and used another truck to pull the bed onto the trailer while I did the bob.
I borrowed my friends Diamond T wrecker to lift up the frame and put it on Jack stands, then used it to pull out the tandem axle assembly.
The issue with using the MRAP springs was that they don't come with lower spring plates and you also need a plate on top of the spring between the springs and axle. Then, because the number and curve of the springs is different than using 5 ton front springs, I also had to weld a solid steel 2" block to the "1 thick spring plate to clear the air cans on the brakes even after turning the cans.
I now have the axle centered and the wheel base is at 192" even from center to center on both sides. I need to weld some centering tabs onto the spring plate to make sure the axles doesn't move now they are in final position. I replaced all the air lines as well.
I'm going to repaint the truck while I have it apart before I put the bed back on.
I also did not plan for the diameter of balancing wheel on the driveshaft which is sitting very close to cross member when suspension compresses. I will have to notch it out to avoid clearance issues when the spring needs to compress.
When I looked at all the work and cost that was involved I decided to just go ahead and Bob it to eliminate the control arm bushings altogether.
I used a set of mrap springs that I purchased in the classifieds and this is where I'm at so far.
I also decided to swap in an axle with a Detroit locker in it.
before picture
Work begins.
I also took on this task in my driveway with limited tools at my disposal. I am getting very good at borrowing what I need.
I put my 5 ton trailer behind the crew cab unbolted the bed and used another truck to pull the bed onto the trailer while I did the bob.
I borrowed my friends Diamond T wrecker to lift up the frame and put it on Jack stands, then used it to pull out the tandem axle assembly.
The issue with using the MRAP springs was that they don't come with lower spring plates and you also need a plate on top of the spring between the springs and axle. Then, because the number and curve of the springs is different than using 5 ton front springs, I also had to weld a solid steel 2" block to the "1 thick spring plate to clear the air cans on the brakes even after turning the cans.
I now have the axle centered and the wheel base is at 192" even from center to center on both sides. I need to weld some centering tabs onto the spring plate to make sure the axles doesn't move now they are in final position. I replaced all the air lines as well.
I'm going to repaint the truck while I have it apart before I put the bed back on.
I also did not plan for the diameter of balancing wheel on the driveshaft which is sitting very close to cross member when suspension compresses. I will have to notch it out to avoid clearance issues when the spring needs to compress.
Last edited:
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