Hi Jim - new Alcoas with 225/75/16 Michelins 2 yrs ago. Wear appears pretty even across the tread. Ride height I will check again, but we settled the torsion bars 3 times (height adjusted) before the alignment, camber set as close to zero as we could. Front shocks are Bilsteins and appear good/ride well. The tire wear may or may not be related to the torque steer, but the torque steer needs to be addressed assuming it should not be as noticeable as it is. So, I'll check the height and head over to the alignment shop for a recheck and consult. Any other ideas to check when we get it on the pit, please let me know.

Happy trails Jim.

My coach drives and rides as well as ever. Virtually no wander any more, and tracks straight with no hands on the wheel. But there is noticeable torque steer - accelerating from a stop, accelerating on the highway - and now I see the front tires are wearing about 2X as fast as the rears. This is after a 1 ton front end, new steering box, new torsion bars, corrected ride height, and a professional alignment (not a GMC expert, but has done a few of them), and a new motor mount.

So, how best to investigate this one, how concerned should I be (as far as using the coach), and where to start?

Jim Hupy mentioned an alignment review when we stopped by his place (thanks again Jim), but what do I tell my guy to check? I was there for the alignment, he did it to spec that I got from this forum. The torque steer was noticeable before the alignment, but I knew the motor mount was failing. Replacing the mount helped a lot, but did not eliminate the problem, and Jim and I did not notice excessive engine movement with brake on/accelerator on.

I would love to solve this one permanently.

Jeff

Good question, Bob - on acceleration the coach wants to go right a bit, I am correcting by turning the steering wheel a bit. When the acceleration is done it stops, goes straight with no "correction". Very noticeable from a stop, but also a bit on the highway when into the pedal.

I cannot say what it did before the 1 ton conversion. It became pronounced (or more pronounced) after the recent front end stuff - torsion bars, pork chops, ride height and alignment. Prior to all that, the ride height was nearly 2 inches low in front. After the height and alignment, it was immediately noticeable, but the motor mount was busted so I blamed that. The new mount took some of it away, but not all.

This weekend I will take height measurements and post them, and next week I'll talk to my alignment guy using Mr. Work's post as a guide. Any advice in the meantime I would appreciate.

Jeff

Bob,

Thanks for the further education. I was thinking that if he had one loose tie rod end the torque applied to that side would allow
the wheel to turn outwards. Did I get that right?

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
USA '75 Avion - Double Trouble TZE365V100426
AUS '75 Avion - The Blue Streak TZE365V100428


-----Original Message-----
From: Bob de Kruyff

""Jeff,

On the OEM front end if you run a line through the center of the upper down through the center of the lower ball joints you will
come up with the steering axis. That's the axis the wheels pivot around when you turn the vehicle. On the OEM front suspension that
line intersects at or near the center of the tire on the ground.

The 1 ton front end has tall spacers that move the wheels outwards to clear the calipers which results in the steering axis inboard
of the tires center. This in turn accentuates any steering problems you might have. Wheel spacers or wheels with a different offset
than the OEM wheels do the same thing.

I would suggest you go through this procedure as you will find where the problem is:
"'

Rob, the biggest factor affecting torque steer (the kind we are talking about here) is "effective spindle length" If you draw the
line as you describe, then you need to measure or calculate the length of the spindle to that line. The length of the spindle is
determined by where the line that goes through the centerline of the tire/wheel. That gives you the lever arm of where the torque is
applied compared to the axis of where the wheel pivots. Some describe torque steer as the tugging of the steering wheel as you
accelerate. That is determined by the side to side torsional stiffnes of the drive train.
--
Bob

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Finally got back to the coach for a drive and some measurements.

1st - what I am calling torque steer is to the drivers side, more a drift than a pull on the steering wheel, and even more pronounced than I remember.

Front ride height is 13 1/8 drivers side, 13 3/16 passenger side with both rears at 11 11/16

Alignment specs when done last May:
LF 0.7 camber 0.5 Caster .02 Toe
RF 0.6 Camber 0.3 Caster .02 Toe
Cross Camber 0.1
Cross Caster 0.2
Total Toe .04
Set Back .12

The only thing I recall from the alignment is that while the front ride height was within spec before I pulled it in, it measured a little high after I pulled it in.

I used the Mueller guide on front end components when I replaced the steering column last winter, everything was nice and tight (no guarantee it still is.

Again, the front motor mount was bad at the time, I changed it out shortly thereafter. Never checked the others.

I do not have a garage at home, just a sloped driveway and 48 hour parking limit, so looking for some guidance if I take it to a shop.

Thanks