Front End Alignment

[Bob Ha]

Had my sons Mustang frontend aligned a few days ago. It was pulling bad to the right. Today I drove it for first time after the alignment and still pulling bad to the right. Wife took it back to NTB where it was originally aligned and they said nothing wrong. They said only thing it could be is the new tire on back is causing the issue. Other three tires are at about 66% left. I'm not an expert but a new tire on back causing a frontend alingment issue sounds fishy. Of coarse he wanted to sale her a new tire so she would have two new tires on back. Anyone know anything about frontend alignments and is NTB full of #$%#. I just can't see how a rear tire causes the car to pull bad in either direction.

 

[kevinj]

Had my sons Mustang frontend aligned a few days ago. It was pulling bad to the right. Today I drove it for first time after the alignment and still pulling bad to the right. Wife took it back to NTB where it was originally aligned and they said nothing wrong. They said only thing it could be is the new tire on back is causing the issue. Other three tires are at about 66% left. I'm not an expert but a new tire on back causing a frontend alingment issue sounds fishy. Of coarse he wanted to sale her a new tire so she would have two new tires on back. Anyone know anything about frontend alignments and is NTB full of #$%#. I just can't see how a rear tire causes the car to pull bad in either direction.

move the new tire to a different location and see if anything changes.

Did the trouble start when the new tire was installed????

Matched axle sets are best

 

[zzvyb6]

Nope that's pretty common, especially if the tire is a different brand and or size. Differences in tire conicity, ply steer, rolling radius and tread depth cause a net torque to act on the car body. Steering the front wheels is necessary to keep the vehicle going straight.

Follow the car and see if its dog tracking: Like an airplane in a cross wind, it runs at a fixed yaw angle while going on a straight path.

Switching the tires may not reveal the problem becauae the net steer moment will follow the tire. SOMETIMES, the steer switches sign if you put the offending tire on the other side of the car.

 

[Bob Ha]

move the new tire to a different location and see if anything changes.

Did the trouble start when the new tire was installed????

Matched axle sets are best

Don't know it's a new car (2004) to us.

 

[Arky217]

Follow the car and see if its dog tracking: Like an airplane in a cross wind, it runs at a fixed yaw angle while going on a straight path.

The 'dog tracking' (never actually heard it called that) is caused by the front and rear axle geometry not being parallel to each other. This was actually fairly common on older pickup trucks.
The cause was a misaligned factory installation of the rear axle, not being perpendicular to the length of the vehicles frame.
Some were so bad that when following one, it appeared that the vehicle was going down the road somewhat sideways (which it was, actually).

If the alignment mechanic wasn't aware of it, it usually resulted in the steering wheel being off centered after he set the toe in.

However, 'dog tracking' in itself is not a cause of pulling to one side (unless, of course, you're going fast enough for wind resistance to factor in)

Generally, if a vehicle WAS running straight, it does not start pulling to one side because of misalignment unless a front suspension or steering component has worn severely enough to cause a substantial change in the alignment geometry, or if the vehicle has hit something hard enough to bend a steering or alignment component, or if someone has changed the alignment from its proper geometry.

The two most typical things that cause pulling to begin are:
* A tire or tires not inflated properly
* A tire or tires worn in such a way as to change its rolling
characteristics (when radial tires first came out, they were notorious for this even when brand new)

Assuming the tires are inflated properly, although I wouldn't say it's impossible for a rear tire to be causing a pulling to one side, I would say that it's highly unlikely and if so, it would be very slight.

If it is a tire causing the pulling, it is likely one of the front tires.
Simply switching the two front tires with each other and observing any change should reveal this.

Of course, there are other things that COULD cause pulling, such as a defect in the power steering or an alignment shim becoming loose and falling out, but if the vehicle was going straight, the other things are fairly rare compared to the tires.

By the way, when testing for pulling, be sure to select a straight, level (not crowned) section of road.

 

[Bird]

Way back in 1991 when I was working in my brother's shop in Anchorage, we ran a coupon in the newspaper for a discount on front end alignments. One of the cars brought in was an almost new compact Pontiac. Our front end alignment guy said it didn't need alignment; was aligned already. So when the customer came to pick up the car that evening, I told him there was no charge. He asked if I drove the car; said it pulled left and he asked if I thought his 300 pound plus weight could cause that.:laughing: So I took it for a test drive with him in the right passenger seat and sure enough it pulled left. I brought in the shop and swapped the front tires, took it for another test drive and it pulled right. Inspection of the nearly new tires revealed nothing unusual so we moved the front tires to the rear and the rear ones to front; problem solved.

In October, 2005, I encountered the same thing with my current 2001 Ford Ranger pickup. It pulled right, so I paid for a front end alignment that didn't help a bit. Moved the front tires to the rear, rear to the front; problem solved.

But personally, I've not known of that problem occurring because of a rear tire. However, I most definitely want, and will have, tires on the same axle to be matched, and prefer all 4 matched.

 

[Diamondpilot]

If you just got the car I would take it to a body shop and have them put it on the frame jig. My guess is the car itself or a axle/spindle is bent. Alignment is going to do you know good. This is all after you try the free stuff first, swapping tires, ect.

Chris

 

[fgross335_2210]

Bought a Chevy Beretta back in 1988 (remember those...what was I thinking?) and from day one it pulled right. Finally got dealer to do an alignment and no change. Then they rotated front tires to rear and it was fine. Dealer said it must be some difference in the runout of these two tires, but it's a tire issue so see goodyear, etc. Goodyear store said "nothing visibly wrong" so they wouldn't do anything.

I upgraded the wheel/tire package and these tires sat in the garage for a couple of years. Installed the tires on a different car later and same exact problem.

If you really want it fixed you'll need at least one more tire......

 

[Peacock]

Swap the front tires from side to side. See if the pull changes direction. Tire pull is quite common.

Different sized tires on the rear will not cause this unless it is an extreme difference. Dog tracking will only cause steering wheel off-set.

The alignment machine, if modern and correctly used, will tell you ANYTHING you need to know to find bent, broken or mis-aligned components.

I do a lot of alignments everyday and have spent the last 11 years doing tire related stuff.

 

[Oldstuff]

I talked to my friend that owns a front end shop and has been doing this work for 44 years. He says that tires are 3/4 of the problems with cars that show up at his shop, this is a high percentage mainly because he is in section of town that is a economically poor community where folks are sometimes lucky to have 4 tires of any quality on their cars. Tires on the front are almost always the problem. The front tires should be the SAME brand, SAME tread type, approximate same amount of tread wear and SAME pressure. Swap the two front tires with each other and see if the pull changes to the opposite direction. He also warns that you need to remember that almost all roads have slope in order for water to drain off quickly. Since it pulls to the right find a 2 lane road that is sloped on both edges and drive in the oncoming lane (MAKE SURE NO TRAFFIC IS COMING TOWARDS YOU) and see if the pull changes to the left.

Oldstuff