Squaring axles under truck

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4 Cruisers, No Garage !
Apr 5, 2008
Menifee, CA
I am in the process of swapping FJ60 axles under my 40 and am having trouble figuring out how to square up my axles under my rig. I am using all new spring & shackle hangers from Ruffstuff as my old hangers were shot in the rear (rivets pulling out of frame on hanger and shackle hanger looked like swiss cheese), and I am replacing the old SRed advanced handling kit in the front. So far, I have used plumb bobs to try and square up the rear axle and have everything tacked on at this point. I am not confident that this is a good method as I know my 40 has been rolled before and would bet money my frame is no longer a good datum to take measurements from. I am in the process of puting the front axle under it and was hoping to get some advice before I tack everything up so that I could possibly save myself a couple of iterations of tacking, measuring, grinding, tacking, measuring, etc..... I guess I will ask some specific questions so as to not leave this too vague.

1. What would be the best method to make the centerline of the axles perpendicular to the centerline of the frame? (This would essentially ensure that the two axles were parallel. If the axles are parallel, but not square with the frame, I would look somewhat goofy driving down the road sideways)

2. What would be the best method of aligning the center of each axle with the center line of the frame so that I'm not crab walking down the road?

3. What are the acceptable tolerances of setting up a suspension and making sure that the axle are square?

4. What am I forgetting, this is my first time taking on such a project?

I really appreciate your input and will be updating with a build thread when I make some more progress.

i believe the factory repair manual has all the measurments of the 40 frame.if the frame is bent unless you know how its bent and where nothing will change unless you fix it .after you square them up see if the wheel base is the same on both sides good luck
The leaf springs in the rear will dictate where the axle will sit, from there it is measuring side to side measurements. For the front, build your new springs hangers as square as possible and from there it the same deal. Measure the side lengths.
measure across, DS spring pad to PS springpad.

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