Excessive Tire Wear

[slabman]

I'm getting some bad cupping on my front tires (Dunlops) of my SUV toad. I've rotated them, then had the alignment checked and yet the new cupping is now apparent on less than 1000 miles of towing. Thoughts?

[slabman]

I'm getting some bad cupping on my front tires (Dunlops) of my SUV toad. I've rotated them, then had the alignment checked and yet the new cupping is now apparent on less than 1000 miles of towing. Thoughts?

[wilanddij]

Check to make sure you have the angle of the tow bar from the MH to the toad within specs. It may be lifting the front end if its too far from level.

[Gary RVRoamer]

If the tow bar angle is within the angle spec and the toad alignment is right (and I mean dead on, not just close enough), I would begin to wonder if the base plates are correctly installed. If they are off center or one side is higher than the other, you can get some strange motion in the front end.

Lexus doesn't approve of dinghy towing as far as I know, but I wonder if they may have too little caster in the front end for good towing behavior? The wheels might be shimmying a bit as you drag it down the highway. As a last resort you might try tying the steering wheel down with a bungy cord to see if that stabilized the front wheels better.

[Route 66]

Gary brings up a good point about front end alignment.

Years ago, some toads needed their front ends adjusted to one end of range of specs, but haven't heard much about that in years.

If the tow bar/baseplate alignment is OK, then the front end alignment might be worth looking into.

[dieselclacker]

Tires can also be an issue. Maybe the Dunlops don't take to being towed. . I had a let of Bridgestones on our towed, and had the same problem as you in that they cupped. Front end was perfect, as was everything else that was checked. I changed to Michelins, and with no other changes, cupping problem was cured. Sometimes a tread pattern that is a little aggressive will develop
a wear pattern when towed, especially on the fronts.

Dieselclacker

[DriVer]

I recently started using what is known as an immobilizer. This device holds the tow bar - draw bar - into the receiver and does not allow it to wobble from side to side. There has been some discussion about this motion causing premature wear on front tires however I can't be sure if the wear presents as cupping. I'm thinking that it's probably scuffing the tires at an accelerated rate. I have been through 3 sets of tires in 60,000 miles or more of towing and my previous 2 sets of tires wore out. The latest set of tires are rated for 60K miles and I have the immobilizer in place and I'm evaluating the efficacy.

[slabman]

When I had th ealignment set, the guy said I waqs off a very small amount on toe. So he set it inward a hair. I told him I heard I should set the caster to the rear (Positive?) as far as Toyota specs would allow-that would minimize cupping. But he was convinced the current setting was the way to go. I think I need to re-visit this when I get back home.

The towbar is level or just slightly down from the receiver elevation, so that's not it. Not sure I can accurately measure the base plate attachment locations to see if anything is off.

Guess I need to hop into the toad and let someone pull me around to see if I hear the front end vibrating.

Finally, I am also thinking the Dunlop tread design is more conducive to cupping than the Michelin LTX might be.

[Gary RVRoamer]

Question: are you sure that towing is causing the cupping? Have you driven the Lexus enough between tows to be sure it is not happening all the time?

[slabman]

Oh yeah, Gary. I'd BETTER have driven it inbetween or I couldn't really make such a claim. Anyway, I did jump in the toad, had a friend tow me and I noted no unusual vibration or other sensation one would expect from tire misalignment. I'm left with the conclusion it must be the tire tread causing the cupping. As soon as I can burn the rest of this rubber, it's off to the store for new shoes.

[Tom and Patty]

Bob,

Take those front tires when you rotate and CROSS them to the back drive wheels. Move the rear tires straight forward. Crossing the fronts allows the torque from the drive wheels to help even out the cupping. Assuming the LX47 is rear wheel drive....what the heck even if it is AWD. AWD set up sends most of the torque to the rear wheels except when slippage occurs. If you do this every 3-5K it should help straighten out the wear. Providing you drive more than tow. Our PT has 11K miles driven and 18K towed.

Some tires are more suseptable to cupping on a free rolling axle.

[slabman]

Thanks, Tom, but I've already done that as well. I don't knoiw what else is left 'cept to swap rubber. BTW... the car IS an AWD model.

[dieselclacker]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by slabman:
Thanks, Tom, but I've already done that as well. I don't knoiw what else is left 'cept to swap rubber. BTW... the car IS an AWD model. </div></BLOCKQUOTE>

Slabman, the answer is Michelins, try 'em, you will like them. Not too agressive on the tread selection though.

Dieselclacker

[Route 66]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Slabman, the answer is Michelins, try 'em, you will like them. </div></BLOCKQUOTE>

I am sold on Michelin Cross Terrains.

I had put them on my Ford Explorer, and they were extremely quiet and smooth.

I'll be putting them on my Yukon soon.