Why does the steering get squirrly while coasting?

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audiocontr
United States of America
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Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Why does the steering get squirrly while coasting?

Post by audiocontr »

I noticed today, while driving down a hill, that if i coast in neutral, the truck has a VERY different feel to the steering. Seemed squirrly. As soon as i popped it back into gear, it was back to normal. Any idea why?
undysworld
Norway
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Joined: Fri Apr 16, 2004 8:08 am
Location: Blue Mounds, WI

Post by undysworld »

I've no idea why you might get worse steering when coasting down a hill, as opposed to driving downhill normally.

My truck was acting squirrely recently after I bent a tie rod on a tree. I straightened the rod, but the alignment was off. The steering was squirrely under normal operation, but got better when I was braking. I corrected the alignment and the problem was cured. You might at least check alignment and for any loose parts in the steering system.

A few years ago, the center pivot needed to be reshimmed. The truck would lurch when I hit uneven pavement. The forces caused the center pivot to make a knocking noise when it moved up and down. Be sure to check this in addition to your tie rods, steering gearbox, etc.
lindenengineering
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Joined: Sat Apr 17, 2004 6:14 pm
Location: Golden Colorado USA
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Post by lindenengineering »

Wandering is a sign of wear in the steering gear or an alignment issue.
Assuming there is no wear remember "coasting" changes the vehicle dynamics so in that condition the symptom can be made worse, as you have reported.
I tend to err towards setting the "toe" to parallel, but I have gone as much as 1/8ths (3mm) with some tyres due to their slip angles.
Point one is to make sure you have the same brand/size of tyre (and wheel) on the axle AND that they are inflated correctly.
Then run the palm of your hand across the tread to see if the tread is showing signs of feathering.
If you are going to check the alignment yourself revert for instructions or take in to a shop and ask for a "toe and go". You might find that the other geometry is out of whack like caster and camber, these will cause the same reported issues but its teardown to do those types of corrections.
Dennis
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OOOps no customer bashing now
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