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Posted By: goneagain 37 front shackles? - Fri Jun 12 2020 06:17 PM
So I rebuild the front shackles on the 37. I can’t say it really handled bad but I knew the bushings were shot so I didn’t give it much thought. The rear bushings on the front springs were badly worn but the front shackles were completely frozen on boath sides.
Now with all new bushings the truck is Squirrley . Can barely stay in one lane at 55. Every thing is new in the front end.
My son has had a few jeeps and he says it a common upgrade on early jeeps( they also have the shackles on the front of the front springs) to reverse shackles to the rear of the springs for better handling. Any body else have this problem.
Posted By: Dusty Re: 37 front shackles? - Fri Jun 12 2020 09:13 PM
Did you put the castor wedges back in ?

Is the toe in measurement correct ?

Stuff may have been previously adjusted to compensate for the worn set up .
Posted By: goneagain Re: 37 front shackles? - Sat Jun 13 2020 12:04 AM
Yes I did put the original caster shim back in. But that doesn’t mean it’s correct. The toe is set at 1/4

Stuff may have been previously adjusted to compensate for the worn set up .[/quote]

Didn’t consider that but makes sense
Posted By: EdPruss Re: 37 front shackles? - Sat Jun 13 2020 03:34 AM
Toe at 1/4, Is that in or out.

Ed
Posted By: goneagain Re: 37 front shackles? - Sat Jun 13 2020 03:47 AM
Sorry toe is 1/4” in. Using an angle gage on top of king pin casting.caster looks to be 0-1 degree positive.
I am running radials.
Posted By: truckernix Re: 37 front shackles? - Sat Jun 13 2020 11:59 PM
So the question I would ask, has the suspension been lowered? If so you may have bump steer. The steering box should be adjusted too to eliminate any problem there.
Posted By: Dusty Re: 37 front shackles? - Sun Jun 14 2020 07:57 AM
1/4" is excessive - you will experience excessive tyre wear. Also twitchy steering smile


The shop manual here specifies 5/64" - 1/8" toe in.

I normally err on the side of caution and go for the smaller figure . I do this in the (possibly mistaken) view that the radials have less rolling resistance and therefore will push the wheels out less .

My tread wear is consistantly even.
Posted By: Joe H Re: 37 front shackles? - Sun Jun 14 2020 12:16 PM
My '37 has 4 degrees caster due to the ride height front and back. It drove OK with 2, but kinda of loose like yours. 4 is much better. The thickest part of the wedge goes towards the rear. Toe-in should be 1/8" when setting in [ as driven position ], meaning all steering joints loaded. If you are using the original style tie-rod and draglink link ends, be sure they are adjusted up tight and the ball end is still round. Did you adjust the steering box? Is it centered? The steering box has a dead center adjustment that keeps the truck going straight without a lot of input from the driver, this will help keep it in its lane.

There is no reason to change the spring mounting, they can drive as good as anything once you get it set right.
Posted By: goneagain Re: 37 front shackles? - Sun Jun 14 2020 01:24 PM
Thank you all for the advice.i don’t know why my brain was stuck on the shackles. Must be an old guy thing..
It’s stance is a little lower in the front and it has power steering. I ordered 6 degree shims thinking I’ll end up with 5 degrees. I’ve read with power steering you can get away with a little more. I’ll change the toe in to a short 1/8” and see what happens.
Another thing I forgot to mention was after rebuilding front springs the steering wheel is off center almost A quarter turn.
Posted By: Joe H Re: 37 front shackles? - Sun Jun 14 2020 03:34 PM
That happens when you lower the front, even a little bit. It will change more when you add the extra caster to it. I had threaded rod made with left and right hand threads, then added tie-rod end to it. This went in place of the fixed draglink so I could dial in the steering box dead on straight ahead. You will have to come up with something similar to correct yours. I bet it turns more oneway then the other. It makes a big difference in how they drive, and if your gear box has variable ratio steering it will be worse when not on center.

Once you get the caster shims in, hookup a couple ratchet straps to the axle and bumper and pull the axle forward before tightening the u-bolts, this will insure the axle is fairly straight as there is some slope in the locating holes. As you tilt the axle with either lowering or caster, it moves the steering arm closer to the gear box, this is why the wheel is off center.

The attached drawing from the '37 Engineering manual shows the arc of the axle verse the steering.

Attached picture '37 truck steering.jpg
Posted By: goneagain Re: 37 front shackles? - Sat Jun 20 2020 12:46 PM
Update
The 6 degree caster shims made a huge difference. Runs straight now. I also added front sway bar Thanks Joe H.
I also plan to ad a rear sway bar but with CCP being in Clovd central it took over a month to get the front sway bar.
These panel trucks are top-heavy.
Again thanks for the help

Bill
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