Alignment Question - Tracking right, printout attached

[timmysurf]

I recently purchased new tires and decided to get my car aligned afterwards, which I typically do whenever I get new tires. Not sure if I just didn't notice before (as I believe the vehicle seemed to track straight?), but after the alignment the car tracks to the right. It's not severe, but enough to be annoying. Driving on the same roads with our Tahoe yesterday reminded me how straight a vehicle should be tracking. I took the car back to check the alignment, they said one of the measurements was off and should be better, but still tracks to the right. Here is the printout, any ideas if other adjustments can or should be made? Thanks

 

[bloc]

Did they give you a print out from the prior alignment job? If so which numbers changed from that “actual” to this “prior”?

If something actually changed I’d wonder whether they were tightening everything enough. The LCA bolts need a lot of torque, far more than most cars, and actually tightening those enough is the kind of thing shops will cut corners on.

 

[timmysurf]

yes, here is the previous alignment printout from the day before. it was from a different shop, not sure if that is why the numbers are different. The first time i took to firestone and based on the results, thought they may have not aligned properly. So the 2nd time i took it to the dealer with similar driving results.

 

[timmysurf]

doing a little research, perhaps adjusting a half degree to the left caster (and still within spec) would help?

 

[drftsub]

Caster can definitely affect / resolve pulling problems however its worth being sure you are not masking another issue somewhere else in the suspension. Another thing to remember is different track width's on different vehicles will make them sit on the "crown" of a road differently and thus potentially feel different even though they are on the same road.

That said, if you are sure you are not "falling to the right" due to road crown (easy to verify in a parking lot etc) adding caster on the left side can help square it up if nothing else looks out of order.

Some things I would verify before artificially changing caster to fix this would be:

• Tire pressure - super common for just a small variance to affect pulling
• Suspension - does it sit level, anything look off?
• I assume since you just had tires done they looked, but without knowing your vehicle age / mileage I would also suggest being sure the suspension isn't worn and the new tires are showing it more.

Hope this helps!

 

[ohsix]

Swap front tires and if the pull changes to the other side it's a tire issue.

I have this issue with my current set of BFG ATs. The issue didn't present itself until the first tire rotation when the tires had ~5,000 miles on them.

 

[timmysurf]

Caster can definitely affect / resolve pulling problems however its worth being sure you are not masking another issue somewhere else in the suspension. Another thing to remember is different track width's on different vehicles will make them sit on the "crown" of a road differently and thus potentially feel different even though they are on the same road.

That said, if you are sure you are not "falling to the right" due to road crown (easy to verify in a parking lot etc) adding caster on the left side can help square it up if nothing else looks out of order.

Some things I would verify before artificially changing caster to fix this would be:

• Tire pressure - super common for just a small variance to affect pulling
• Suspension - does it sit level, anything look off?
• I assume since you just had tires done they looked, but without knowing your vehicle age / mileage I would also suggest being sure the suspension isn't worn and the new tires are showing it more.

Hope this helps!

Thanks, it’s on my 2017 LC with about 30k miles. Didn’t like the OEM tires so switched before they were entirely worn, but seemed to be wearing uniformly. Tire pressure is good all around, no issues with the suspension. Maybe it is due to road crown and I just didn’t notice before... since most of my driving is highway, it’s just a lot more noticeable than our other vehicles.

 

[timmysurf]

Swap front tires and if the pull changes to the other side it's a tire issue.

I have this issue with my current set of BFG ATs. The issue didn't present itself until the first tire rotation when the tires had ~5,000 miles on them.

Interesting, I had balancing issues on the first set and tracking to the right so had another set put on. Was able to balance properly but still tracks right, even after an alignment to double check. Would seem unlikely to have radial pull on both sets of new tires, but can’t rule out.

 

[drftsub]

If you are fairly certain it is nothing mechanical, and it is annoying enough to deal with it. Take it back to Firestone / dealer and tell them it pulls to the right after their alignment. They should know to put some caster in to compensate.

Caster is a non wearing alignment angle (in all real use cases) so it wont hurt anything.

 

[chilibit]

If insufficient caster makes the truck something you must constantly tweak to keep to a lane then you can try to increase it. I have mine maxed but it is still well below factory spec. A one degree increase will make it track better. Sometimes stacked tolerances work against you and that seems to be true for my truck. Mine does not drift in the least, but it wants attention all the time. Wearisome. Usually only an Interstate kind of issue for me.