Amc spicer 20 rear diff mod

[ksouthw80]

I've read all the pros and cons of the 20 rear axle. For the kind of wheeling I'll be doing I think it is reasonable to build mine up. I'm thinking of : stitch welding tubes, 1 piece axles, truss, and detroit locker, 4.11 or 4.56 gears. I'd love the OX manual and am still considering but not sure its worth it on a 20. My main question at this point has anyone used or known anyone who has used the Blue Torch Fabworks rear truss system W/ diff cover? ? Any thoughts or opinions. I have considered making one too but if I can find one built already thats worthy, I'd like to save the time. I'm really wanting this jeep pretty much done by spring. I cant figure out how to post pic and details of their system .

 

[Lumpy Grits]

D/20 with your 35's, is not a good mix.
Detroit Lock is KISS.
W/35's, look at 4:88 R&P.
LG

 

[Peanut Butter]

Is this what you mean: BTF Model 20 Rear Truss System BTF03094 – Blue Torch Fabworks, Inc.



A couple of things I see with this setup. The design is to be used with a 4 link suspension, thus the attachment points on top of the truss. Second would be the length. The idea of a truss is to keep the axle from bending. I would prefer mine to be a bit longer. It is however hard to tell the exact length from the picture.

 

[ksouthw80]

Yes thats the one I'm talking about. Thankyou for posting that up. The brackets for the 4 link come with it unwelded. You may have a point on the length it may run down the tube. I will try to call them tomorrow. I do like the look of taking steel round stock and adapting it to the axle. It seems around here finding axles at a worthwhile price is getting harder unless their 1 tons. I dont want that set up for this jeep. ( the next one will be more for that) I've looked at off the shelf assemblies ( 44's, 9 inch, 8.8's) and somehow I wonder if thats the way to go. I want rear disc too. Anymore, even the salvage yards know what they have and are asking more. I dont know.....

 

[ksouthw80]

AMC 20 Truss

This looks good. I'm somewhat convince making a 20 worthy is possible.

 

[ksouthw80]

what some have done.

 

[Lumpy Grits]

That one to the right, would be the best one.
I won't tell you it's a Ford 9" rear.
LG

 

[ksouthw80]

That one to the right, would be the best one.
I won't tell you it's a Ford 9" rear.
LG

LOL, BUT I knew that ,, just looking at examples. We all know what needs to happen to make a 20 work (harder). Hey Lumpy?,, in the aviation business I dont deal much with STEEL Stock, In your opinion what ID and or OD do you think is best? Would you do me a favor and look at the website I posted, not just the order part. Please let me know what you think.. Anyone else too please give opinion.. Hey, I know I may end up being one of the guys "on the other side of the 20", and if it breaks right away I'll ship cases of beer to the I told ya so's, but I'm seeing some reasonal objectives about the 20. If i did buy an off the shelf axle it will be bare for me to build. Before I stroke the check I appreciate some opinions. This jeep is intended to be a very capable but still a CJ jeep. The next jeep i build will have to be trailered due to unstreetworthiness. I had 2 jeeps in the past and I'm trying to make this what I WISHED for in the day. It most certainly will be wheeled but mostly in local states... I'll go now

 

[Lumpy Grits]

1/4" thick truss plate is fine. If anything, it's 'overkill' as 3/16" would work just as well and lighter to ship.
The BIG issue I see with that truss, is underbody clearance and such.
LG

 

[ksouthw80]

1/4" thick truss plate is fine. If anything, it's 'overkill' as 3/16" would work just as well and lighter to ship.
The BIG issue I see with that truss, is underbody clearance and such.
LG

I haven't flexed a cj axle in years but it does look to add 4 to 6 inches of height.

 

[Peanut Butter]

1/4" thick truss plate is fine. If anything, it's 'overkill' as 3/16" would work just as well and lighter to ship.
The BIG issue I see with that truss, is underbody clearance and such.
LG

Fabrication is an art in itself. If you can do it, I would go with 3/16" steel with a 1/4" top. You can make the truss so that it just barely went over the pumpkin, but extended out over the length of the axle tubes. Again the purpose here is to keep the tubes from bending. I haven't started my AMC20 rebuild yet, but that's my plan.

As for the link you provided, that is a neat design, but the height seems to be a factor for me too. If you have a 4" lift that would most likely work just fine, anything less and I think your going to have clearance issues. For the price, it's a good deal. Nice CNC cut bendable truss!

 

[Posi]

If I ran a 20 I would weld the tubes, add one piece shafts, and call it a day.
It will last forever if you don't wheel it hard.

 

[Lumpy Grits]

The one truss I built for a 20, used 1 3/4" OD .125 wall DOM 4140 round tubing.
Fitted & welded the ends just inside the inboard axle u-bolt and bent and welded it to the top of the carrier housing.
IIRC, the tube cost me $25-$30.00 and a full afternoon(w/beer)for the install.
LG