Build Project Lockjaw-1973 Fj40 on Tons

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I have 5.3 vortec and nv4500 with Orion HD tc. Mild to hard trails. Nothing crazy. I don’t have a heavy foot. I would be happy to the Toyota axles but…… I run Toyota axles forever and already have the fj80 axles. 38-39’s would be fine. It’s more of a solid trail rig. I would like start attending 1-2 TCLA events annually. Rubicon and Moab, and similar stuff.
 
Paul said:
I have 5.3 vortec and nv4500 with Orion HD tc. Mild to hard trails. Nothing crazy. I don’t have a heavy foot. I would be happy to the Toyota axles but…… I run Toyota axles forever and already have the fj80 axles. 38-39’s would be fine. It’s more of a solid trail rig. I would like start attending 1-2 TCLA events annually. Rubicon and Moab, and similar stuff.
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I would say if you own them run them.
I think they will be fine for your intended use.
 
I think that Paul has FJ80 and 1-ton axles if I remember correctly from our chat earlier in the year.

There are a few reasons for why I would steer away from tons.

  1. If someone was not planning to run a tall tire, like something over 40”, the ground clearance won’t be great. My D60 is fine but the C14 needs a shave, even with 40” tires. I drag it over everything. The plus side is that it’s super beefy and it doesn’t get hurt, but neither did dragging my stock 40 axles on rocks.
  2. If I were wanting to keep the Cruiser low with a moderate lift under 4” and 37” or smaller tires. Packaging in the rear is fine but trying to stuff the bulk of a 1-ton axle under the front frame horns was a challenge and I doubt that I would have been able to have done that with a significantly lower stance.
  3. If weight were a concern. These tons are at least 5-600lbs heavier than Toyota axles. My truck weighs 5700lbs without the hardtop and doors so the extra weight from the axles isn’t much, but it all adds up quickly.
I am very satisfied with my setup and I am planning to run it this way for a long time, plus I plan to do 8-9 rated trails out of 10. I would probably use FJ80 (or FJ60) axles on my next build if I ever do another one. It will be on 3” of lift with 35-37” tires and I would run up to 7-8 rated trails with it. It’s a tough decision for your build, Paul, as you are right on the edge between specs. I’m not sure that it is worth swapping out transmission internals and a transfer case to run tons with your driving style. I may honestly go the FJ80 axle route if I were in your shoes, but I get it and now is the time to decide as you will want to spec your suspension for the unsprung weight of either axle setup. Either way you go it’s going to be awesome to see.
 
Mike Shull said:
I think that Paul has FJ80 and 1-ton axles if I remember correctly from our chat earlier in the year.

There are a few reasons for why I would steer away from tons.

  1. If someone was not planning to run a tall tire, like something over 40”, the ground clearance won’t be great. My D60 is fine but the C14 needs a shave, even with 40” tires. I drag it over everything. The plus side is that it’s super beefy and it doesn’t get hurt, but neither did dragging my stock 40 axles on rocks.
  2. If I were wanting to keep the Cruiser low with a moderate lift under 4” and 37” or smaller tires. Packaging in the rear is fine but trying to stuff the bulk of a 1-ton axle under the front frame horns was a challenge and I doubt that I would have been able to have done that with a significantly lower stance.
  3. If weight were a concern. These tons are at least 5-600lbs heavier than Toyota axles. My truck weighs 5700lbs without the hardtop and doors so the extra weight from the axles isn’t much, but it all adds up quickly.
I am very satisfied with my setup and I am planning to run it this way for a long time, plus I plan to do 8-9 rated trails out of 10. I would probably use FJ80 (or FJ60) axles on my next build if I ever do another one. It will be on 3” of lift with 35-37” tires and I would run up to 7-8 rated trails with it. It’s a tough decision for your build, Paul, as you are right on the edge between specs. I’m not sure that it is worth swapping out transmission internals and a transfer case to run tons with your driving style. I may honestly go the FJ80 axle route if I were in your shoes, but I get it and now is the time to decide as you will want to spec your suspension for the unsprung weight of either axle setup. Either way you go it’s going to be awesome to see.
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Does adding a doubler (black box or Magnum) or otherwise increasing the ratio change any decision made about the axles or is it just easier on the transmission/TC when the going gets tough?
Seems to me it does not from the math, but it might change driving style and therefore cause axles to handle more?
Does this logic make any sense?
 
Ditcherman said:
Does adding a doubler (black box or Magnum) or otherwise increasing the ratio change any decision made about the axles or is it just easier on the transmission/TC when the going gets tough?
Seems to me it does not from the math, but it might change driving style and therefore cause axles to handle more?
Does this logic make any sense?
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Sure, though you can break anything with low gearing and good traction, but you already know that from your farm equipment. I’m 5.72:1 in the transfer case and I can get pretty twisted up on an obstacle where the energy goes into the drive terrain but the Cruiser doesn’t move. I’m sure that something in the 1-ton setup would break if I kept going.

20+ years ago my friends ran doublers in their mini trucks with welded rears and locked fronts through tough Utah terrain without a problem. Toyota has incredible strength. I was the only one in the group who broke anything and it was a stock 3-speed Cruiser transfer case, but never once broke a ring gear or axle. We weren’t running 40”+ tires. 38’s were the largest. I had 36x15.5 swappers.
 
Ditcherman said:
Does adding a doubler (black box or Magnum) or otherwise increasing the ratio change any decision made about the axles or is it just easier on the transmission/TC when the going gets tough?
Seems to me it does not from the math, but it might change driving style and therefore cause axles to handle more?
Does this logic make any sense?
Click to expand...
Huge Hijack to bluehawk's thread you need to start a thread if you want to ask more questions 🤷‍♂️
 
Broski said:
Huge Hijack to bluehawk's thread you need to start a thread if you want to ask more questions 🤷‍♂️
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I’m thinking that one of us should just start another thread for Paul and we can all hijack it with whatever we want to talk about until Paul has something that he needs to iron out.
 
Got some more paint on Stretch this past Saturday
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Great progress, looking good!
 
I love that color.
 
Decided to do a little powder coating while I had a little down time. Got a hood latch from NY and decided to blast and coat with some matte black. Here is before and after
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Well, more shenanigans in the garage. Decided to take the rear hatch handles and all the associated parts and powder coat them.
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So I dug out all of my rear pieces of quarter window glass. Come to find out, there are two different sizes of glass. Is there a way to measure them other than just sticking them up in the opening? I’ve got some really small ones and I have some that have the one piece rubber gaskets. Also how to tell which is left and which is the right side?
 
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Got it all figured out.
 
Progress has been slow lately. Been doing rust repair on a friends LX470.
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Man, that thing is eat up. I hope he got a heck of a deal on it.
 
jynx said:
Man, that thing is eat up. I hope he got a heck of a deal on it.
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Not sure what he paid for it. Not a bad first car for a 16 year old
 
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