Author Topic: Truck wanders all over the road  (Read 758 times)

Offline zacksmith03

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Truck wanders all over the road
« on: February 12, 2020, 11:11:28 PM »
The steering play on my 1975 k10 with a 4in. lift is tight, but the truck still wanders more than it should. My dad suggested that I put some 6 degree shims under the front leafs to drop it back and make it drive straighter down the road. What's y'alls opinions about this? Pinion angle is good right now, and I don't want to break stuff or cause any more problems.

Offline Mario

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Re: Truck wanders all over the road
« Reply #1 on: February 18, 2020, 06:12:09 PM »
It's called positive caster, and it's fixed on our trucks.  It shouldn't have changed with the lift springs.  Especially if the springs didn't have shims.  If you add shims to help the front drive line angle, then you'll change the way it handles.  Zero caster angle will wander.  The only way to have zero front drive shaft angle and positive caster is to cut, rotate, and weld the kingpins on the axle tube.  A few degrees of angle on the front drive shaft won't hurt.  If the springs came with shims, then maybe that's your change that is affecting the caster and making it wander.  4 degrees might be too much of a change to the caster.  I've had the feeling that you are describing when the front tire pressure was too high, and when the tires were new.  I would start at 36 psi, then adjust up or down based on the feel.
Mario
Santa Cruz, NM
1972 C10 4x4 350 350TH NP205
1981 K20 355 NV4500 NP208 GM14SF GM10
2005 3500 Duramax Allison 5spd

Offline JohnnyPopper

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Re: Truck wanders all over the road
« Reply #2 on: February 20, 2020, 08:00:28 PM »
Take it to an alignment shop and have them measure the castor before you do anything.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

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Re: Truck wanders all over the road
« Reply #3 on: February 21, 2020, 04:19:34 PM »
Caster is not your problem. You have something loose, so recheck the steering & suspension loaded and unloaded.
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Offline ezstriper

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Re: Truck wanders all over the road
« Reply #4 on: July 06, 2020, 02:45:58 PM »
if you have changed springs/etc and the alignment is in 0-neg caster it will make the truck wander badly. Yes you can add shims to correct this, but you need as stated before find out where the alignment is now..excessive toe out will also do it.

Offline JohnnyPopper

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Re: Truck wanders all over the road
« Reply #5 on: July 06, 2020, 06:30:14 PM »
Maybe there were shims and the lifto maniac put them in backward and now you have negative castor but no one on God's green earth will ever know till you get it in gear Mate!! How's that for run-on???
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction