18 Mustang left pull

I have base 18 mustang gt at 2300 miles.
Around 1500miles I got used oem pp wheel and wrapped them with new nitto 555 g2s. 275 rears 255 fronts.

After the installation the car started leaning to the left. it is not much but for a brand new car it annoys me a lot. especially when I am coming to a stop the steering wheel turns to the left by it self (like 1/10th of a full rotation). Also when I go straight constant speed steering wheel turns to the left very slightly. If I keep the steering wheel straight there is no pull to any direction.


I complained about this to the discount tire stating that it might be due to a bad tire. they rotated the tires all the possible ways and it was the same. After each rotation car kept pulling to the left. Never to the right.

Then I got dealer to check the alignment. I got a paper from the dealer that states alignment is good and took it to discount tire.
Discount tire gave me new front tires. and still same pull to the left.

At this point the discount tire told me they wont help me anymore. Not really mad at them since they tried everything except giving me new rear tires.

:frusty: What can be the reason for this?
Since I sold stock wheels cant try them. :shrug:


rotation direction of the wheels were good at all times
tire pressures are right on. I am planning to use the right side 1psi lower if I cant solve this.
I have them check the rims each time and they said rims are good.

Most of the time that's an alignment issue. 10% of wheel turn is pretty bad and an alignment shop should have caught that. You could try taking it to another alignment place, dealerships don't always have the best reputation for that sort of thing.

If its not the alignment, then something is loose in the suspension Do you get any clunking noises?

NightmareMoon said:

Most of the time that's an alignment issue. 10% of wheel turn is pretty bad and an alignment shop should have caught that. You could try taking it to another alignment place, dealerships don't always have the best reputation for that sort of thing.

If its not the alignment, then something is loose in the suspension Do you get any clunking noises?

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nope it rides very good. and havent heard anything. also when it was up on the lift in tire shop, I tried to shake them but they were solid.

edit: I havent expected thought that dealer alignment might not be good. I will get it checked to a alignment shop

Does the issue happen everywhere you drive, or does it occur on the same sections of road? I ask because the more aggressive tires may be pronouncing tramlining effects, and certain sections of road can have enough crowning that can pull a wheel quite a bit.

Other than that, I’d say it must be alignment related, or perhaps your used set of PP wheels has three 9.5” wide wheels and one 9” wheel.

Roadway 5.0 said:

Does the issue happen everywhere you drive, or does it occur on the same sections of road? I ask because the more aggressive tires may be pronouncing tramlining effects, and certain sections of road can have enough crowning that can pull a wheel quite a bit.

Other than that, I’d say it must be alignment related, or perhaps your used set of PP wheels has three 9.5” wide wheels and one 9” wheel.

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I thougt about the crown issue. To make sure thats not the case, I drove on the many streets in both directions to check. But was always left pull.

Never thought about having not the same wheel widths on the axels. I just thrusted to the guy that I bought from. By just looking at how much tire sticks out from the wheel, they seems same to me but I will try to check the wheels sizes.

Today I talked to a alignment shop he said alignment can only cause uneven tire wear not pull. I guess i need to see other alignment shops.

Do you have a copy of your alignment sheet handy? Please post it if you do.

ponyv6 said:

I thougt about the crown issue. To make sure thats not the case, I drove on the many streets in both directions to check. But was always left pull.

Never thought about having not the same wheel widths on the axels. I just thrusted to the guy that I bought from. By just looking at how much tire sticks out from the wheel, they seems same to me but I will try to check the wheels sizes.

Today I talked to a alignment shop he said alignment can only cause uneven tire wear not pull. I guess i need to see other alignment shops.

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Does it take constant effort to keep the car going straight, or is the steering light despite being off center?

If it takes constant effort to go straight, that may be some issue with a tire, hub, loose part, or a really really bad alignment.

If the wheel is just off center, but the car goes straight, that’s easily corrected with alignment.

How heavy or light your steering feels, and how much it wants to self center or dart to either side is also controlled by the alignment.

Anyway first thing I’d do is take it to a reputable alignment shop, preferably one that the local Track guys or autocrossers use and have the, take a look, fix anything that’s off, and get you a printout of the measurements. If that all checks out then it’s something odd.

Roadway 5.0 said:

Do you have a copy of your alignment sheet handy? Please post it if you do.

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I am in between moving the houses but I will look for it. No idea where I might have put it.

NightmareMoon said:

Does it take constant effort to keep the car going straight, or is the steering light despite being off center?

If it takes constant effort to go straight, that may be some issue with a tire, hub, loose part, or a really really bad alignment.

If the wheel is just off center, but the car goes straight, that’s easily corrected with alignment.

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when the steering wheel centered it goes straight. if I dont hold the steering wheel straight it tends to turn left.

fronts already had 2 sets of brand new tires. We only havent tried replacing the rear tires. Can a rear tire defect cause this?
I dont wanna ask anybody for their wheels but if you think so, I might try to barrow a friends rear wheels and try. :shrug:

how can I check the hub and loose part?
the only thing that I did when the car was on lift, I tried to see if the fronts has any extra friction compared to the other. I tried to spin them equal force and measure the rotation. they were ok. :frusty:

If it helps it does it more at low speed.

Weird.

Yeah, IDK. Sounds like the alignment may be ok if it tracks straight when the wheel is straight. I would think that rolling drag on any corner (rear included) would cause it to pull that direction. I don't know much about tire defects that would cause this sort of thing.

If the hub is going out, you can detect that by jacking up that corner, and seeing if there is any play in the hub by pushing/pulling on the top and bottom of the wheel (with some effort). If you can rock it around the hub is out. Often they'll make noise when they're going out, but not always.

You could try swapping your rear tires left to right and see if it pulls the opposite direction. Even if the tires are directional this would be fine to try for a short while.

Roadway 5.0 said:

Do you have a copy of your alignment sheet handy? Please post it if you do.

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here is the alignment sheet
thanks

ponyv6 said:

here is the alignment sheet
thanks

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Your thrust angle may be the problem. While 0.06 isn’t huge, it should be 0.00. Positive thrust angle will cause the car to steer left as I recall. I good alignment shop can square you away, and certainly can get your rear-toe symmetric.

Roadway 5.0 said:

Your thrust angle may be the problem. While 0.06 isn’t huge, it should be 0.00. Positive thrust angle will cause the car to steer left as I recall. I good alignment shop can square you away, and certainly can get your rear-toe symmetric.

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appreciate the answer. I will look in to it. If positive thrust angle actually causes left pull I will mention this to the dealer. since they did the alignment, I will try to go for a free alignment correction.

Roadway 5.0 said:

Your thrust angle may be the problem. While 0.06 isn’t huge, it should be 0.00. Positive thrust angle will cause the car to steer left as I recall. I good alignment shop can square you away, and certainly can get your rear-toe symmetric.

Click to expand...

you are right! this is what I found:
"A positive thrust angle will try to steer the vehicle to the left, while a negative thrust angle will try to steer the vehicle to the right. This will cause the driver to pull the steering wheel right or left to compensate."

Now the question is 'can 0.06 in +-0.5 tolerance cause this?'
hopefully the dealer would take me seriously.