Page 1 of 1
Wheel alignment question
Posted: Sat Dec 26, 2009 9:54 pm
by PhillT
Can toe-in or toe-out affect only one front tyre, or does it affect both by the same amount and on the same side of the tyre, i.e both worn inside edge or both worn outside edge?
Posted: Sun Dec 27, 2009 12:28 am
by alien
you'd assume that it'd affect both - but if just one side is out then the compensation you'd be doing at the steering wheel would wear the bent side more... but that'd only happen with a bent housing etc. if the tie-rod is out of adjustment then you should wear both evenly as the tierod purely holds the wheels in alignment.
sound stupid - but have you checked tyre pressures match between both?
Posted: Sun Dec 27, 2009 2:40 am
by PhillT
Alien, that is what I thought. You would expect that to keep the car going straight the wheels would split the difference and side-slip equally.
Here isa the whole story. The LHS wheel has far more negative camber than the RHS (which I have to fix soon) , but the RHS tyre is severely worn on the inside, and the LHS is worn very evenly. This would suggest that camber is certainly not the problem. That only leaves toe-out. I just cannot figure why toe-out would affect one side only.
The LHS has roughly 7 degrees negative camber. RHS is only about 2 or 3 degrees.
Tyre pressures are even and checked regularly. There is rarely a need to adjust pressures as both hold pressure well.
Posted: Sun Dec 27, 2009 9:37 am
by VR Rodeo
Kingpin bearings perhaps ? What is the steering like ?
Below is how to roughly check for toe in/out, stolen from here :
http://www.trail-gear.com/tech/sas-inst ... tions.html
Place the steering wheel so that it is in the center of it's movement left to right. Bolt on the pitman arm using the stock nut and washer. Connect the left side of the steering Drag Link to the the front most hole in the right side steering arm. Tie rod ends should have approximately 3 three exposed threads. Do not expose more than 1/2 of the tie rod end threads as this can cause an unsafe driving condition.
With the truck on the ground, set the tow-in of the front tires at 1/8". This is done by turning the Tie Rod with the jam nuts loose. Measure the widest part of the tire at the front and rear of the tire. Adjust the Tie Rod until the front is 1/8" narrower than the rear.
Once completed turn the steering wheel all the way left and right. Verify that the wheels turn the same amount left and right. If not, adjust the length of the drag link or adjust the position of the pitman arm.
Tighten the pitman nut to 130 ft/lbs. Tighten the jam nuts on the Tie Rod and Drag Link using an adjustable wrench.
http://www.trail-gear.com/tech/sas-inst ... 18-600.jpg
Posted: Sun Dec 27, 2009 11:16 am
by PhillT
I checked the toe yesterday and there is a little toe-out.
Suspension etc is all as new, drives perfectly.
Still no one with an answer to the question, "Does toe affect both tyres the same"?
Posted: Sun Dec 27, 2009 5:40 pm
by alien
of course it does... its a central adjustment that affects both wheels - however if the draglink is out then you'd be holding the wheel crooked to go straight, but the tie-rod keeps the angles of the wheels the same each side.
Posted: Mon Dec 28, 2009 2:44 pm
by PhillT
Well I agree with your thinking, so what caused this to happen? It has affected only about 25 to 30mm in from the very edge, and there is no sign of feathering, just cleanly worn down. The search continues :-(
Posted: Mon Dec 28, 2009 3:08 pm
by alien
i'd check for a bent diff housing.... if one wheel is cambered more than the other, it would be dragging you off to one side so you'd be constantly correcting for that and hence wearing the tyre unevenly.
roll a coin along your desk - watch what happens as soon as the coin leans a bit - it does a big arc and eventually falls over... apply that to 2 coins (your wheels) and have one leaning and one straight - to counter the leaning wheel the straight one must turn half the distance of the lean, which places more weight on one side of the tyre than the other and causes uneven wear.
Posted: Mon Dec 28, 2009 5:27 pm
by PhillT
Diff housing looks fine. Car drives straight when I let go of the wheel on a flat road, no hint of sideways movement. Steering wheel is centred when going straight too.
Posted: Mon Dec 28, 2009 5:45 pm
by alien
lol - time to take it to a tyre shop to be checked over =)
Posted: Tue Dec 29, 2009 7:04 pm
by zukimudman
if its got neg 7camber on one side and neg 2-3 on the other side and the tow is not set up right theres ya prob and if its got neg 7 dec u got sumthing really wrong not even drift cars run that much
Posted: Tue Dec 29, 2009 8:10 pm
by PhillT
I got under there yesterday, and it is now about 1 or 2 deg. on both sides. The camber bolt was loose on one side, and had rotated. Having said that, that side tyre is worn even, so probably has not been loose for long. The neg. camber is just visible to the eye now. Looks sane again.
Still can't explain wear on one side only though. See what happens now.
