First a little background: A few years ago, I was involved in a minor fender-bender. I had the car repaired, including frame straightening. Later on, I bought a lifetime alignment agreement at a shop. My car never pulled, and it seemed well-aligned.
Forward to last week, when I had to replace my struts, CV shafts & tie rod ends (really). I then took it to a different shop than before for an alignment. Afterward, the car pulls, not sharply, but still very definitely, to the right. As an aside, and no explanation yet, the car squeaks on that side going over bumps, both front & back. The mechanic showed me that there is a 1/2" difference, left to right, in the distance between the front & back wheels. He said that my prior mechanic must have been toeing-in my wheels to compensate, essentially fudging it. He also said that unless I get the body shop to straighten the frame, they won’t be able to really align the wheels.
Does that make sense? I can see that if that were true, it might pull during a turn, or while on a surface with a slope or hump. It pulls all the time, and strongly. Am I deluding myself?
It’s difficult to make much of a guess on this without knowing the specifications as given by the alignment rack, if any suspension components were replaced after the wreck, etc, etc.
However, the 1/2" difference from one side to the other is pretty large and does mean there is a problem.
Guessing a bit, I would say that whoever was behind the frame straightening was off base.
I would also add this. Many body shop people are not mechanics. While they may bang out a fender and apply paint in a professional manner, many of them are not that sharp when it comes to the mechanical parts of a damaged car.
I’m also having a hard time seeing a 1/2" difference being caused by toeing the wheels in or out. That could be due to caster differences and could point to subframe, control arm, or strut tower damage.
Sorry I can’t be more precise. If you have a printout of the alignment you might check the caster and camber specs closely. Both sides should be close to each other with the right side (preferably) having a tiny bit more negative camber and caster as compared to the left. Hope that helps in some way.
Normally I’d suspect frame damage, especially considering the history, but to have all of that suddenly appear after having that amount of work done suggests that it would be prudent to go over the work completely, as well as verifying the correct strut part numbers were used.
It mght also be prudent to check dimensions on the frame itsel rather than the center to center wheel dimensions. If you’re actually off 1/2" and body shop shoud be able ot confirm it without using the frame straightening table. I say “body shop” because they’re used to centering on frame dimensions rather than suspension component dimensions. Checking this would conclusively determine whether the problem was in the frame or the suspension components, and that might be key to solving it.
Talk with your insurance too if it turns out to be damage. Perhaps they can reopen the original claim and cover more extensive work if necessary. It doesn;t cost anything to ask.
A 4 wheel independent suspension requires a 4 wheel alignment and the 1/2 inch deviation from side to side should have been determined immediately when the car alignment was checked and not required returning with a complaint before finding it. And the deviation may be the result of a worn trailing arm bushing or a bent trailing arm. Try another shop.
This mechanic is full of bull. Most cars have a different track widths between the front tires and the rear tires. For example, on my 97 Accord, the factory service manual shows that the center to center distace of the rear tires is supposed to be 59.1 inches (1500cm) and the center to center distance of the front wheels is 59.6" (1515cm).
My bad, I misread the post. I have to agree with all the others above.
Keith, you bring up an interesting point. I’m interpreting the OP as saying the distance between the front and rear axles varies from the left side to the right side. You’re interpreting the description as being the track, the difference between the right and left wheel centers.
OP, which is the accurate interpretation?
Guys, first, thanks a lot for the responses.
The distance between the driver-side front & rear wheels was different from that between the passenger side front & rear wheels.
And also, as far as the toe-in, the mechanic said maybe the previous shop had been toeing-in the front wheels all along to compensate for the pull, and just never told me. I wasn’t sure how well that would’ve worked.
When there is an excessive deviation from parallel of the front and rear axles center lines a vehicle will “dog trot.” In the rural south abused pickups are commonly seen driving with the rear end askew when the line up pin on the rear axle shears off and allows the axle to slip on its perch. Aligning FWDs includes setting that parameter.
Up here we call it “crabbing”, or “going down the road at a crab angle”.
I agree, Rod. And I still think the first step is to have the work gone back over completely including verifying part numbers. I’m assuming the rear shocks were replaced as well based on the post and it’s entirely possible that the root cause lies in something that was done. Perhaps someone forgot to realign the rear as well as the front.
Certainly, mountainbike, a good alignment shop should have immediately recognized such a problem. I would have my doubts regarding the abilities of a shop that didn’t find the problem until the customer returned with a complaint. And, come to think of it, I have heard the condition called “crabbing” also. Maybe when I was on the coast. All we know of crabs here is crab cakes at Red Lobster and they aren’t really very good.
Lots of great advice gentlemen. Sorry if I missed it, but did sam-bishop have a 2 wheel or 4 wheel alignment? Always go with 4 wheel alignment because it measures and takes in to consideration the critical issues of setback and thrust angle of the vehicle. Discussing it with the insurance company at this juncture is going to be less than rewarding. Typical stance by the insurance company is going to be that “we paid X body shop to do the job properly” which is true, but it doesn’t hurt to talk to them. A lot of insurance companies guide you to their approved repair facilities because it is less costly to the insurance company. The ultimate responsibility for performing the repair correctly lies with the body shop. Body shop personnel are certified just like automotive technicians, and it takes special training to operate a frame straightening machine. If there is a frame issue, consult a reputable body shop. A minor fender bender should not have involved a major frame repair, but might have called for a frame “pull” so that body components aligned correctly.
When cars need to have their frames straightened after an accident, they should be totaled instead. Once the structure of the car starts to collapse, as it’s designed to do, they are never quite the same after that…
Many cars are indeed totaled by insurance companies for that reason…But then they turn around and sell them at auction to the highest bidder. That bidder is likely to be a rebuilder not a salvage yard or scrap dealer…The rebuilders can make them look brand new…
Rod, crab cakes are an acquired taste. But they’re only good made fresh.
Caddyman, I agree, but I’m not convinced that we know yet whether the frame is actually sprung. A bodyshop should be able to determine this. If the work p[erformed were to be verified to all be correctly done, including a 4-wheel alignment, then I’d move to wanting to check the body.
“First a little background: A few years ago, I was involved in a minor fender-bender. I had the car repaired, including frame straightening.”
I am curious as to why if you purchased a lifetime alignment at one shop that you paid another shop to do this alignment? And I still think your current mechanic is wrong. Dogtrot or crabbing will be caused by the alignment of the rear wheels, not the front wheels or by the distance between the wheels on each side of the car.
Now if the rear tires are knocked out of alignment that causes the differential in front to rear wheel spacing, then the vehicle will dog trot. If the differential was caused by the front wheels, it will not dog trot. Was the fender bender to the rear or the front of the car?
If the accident was to the rear, then my apologies to the mechanic. I was assuming that the fender bender was to the front for some reason which would make him wrong.
Frame straightening can be a very minor thing. Todays modern vehicles are designed to absorb and deflect energy upon impact. It is a very common issue to have a frame rail pulled and/or straightened as part of a minor fender-bender. If the entire frame is twisted, that’s a whole different issue, and certainly does not come under the heading of minor fender-bender. Some manufacturers are even using bolt-on frame members (called crash boxes) to aid in the repair process. As Mountainbike has stated, the 1st step is alignment verification. The setback specifications from the 4 wheel alignment need to be discussed 1st
At the risk of being repetitive, the problem referred to is “setback”. If the 2 rear wheels are the same distance from a reference point at the rear of the frame & the distance from L/F wheel to L/R is 1/2" less than distance from R/F wheel to R/R, the R/F wheel is said to have “1/2” setback". Rule of thumb is .25" or less setback is OK. So there is too much setback but not super severe, I would say.
What year Nissan Sentra? I will go on our alignment rack tomorrow & see if rear toe & camber are adjustable on this vehicle.
Since you spent some big bucks on this repair, you should ask them to see if they can straighten out these bugs. The trick is to give them enough time to really re-check everything. If you go in & wait while they do this, the tech feels rushed & will probably miss something. I speak for myself, anyway.
Mntnbike is right on as far as double checking the part #'s & the rear alignment.
After they get the alignment angles OK, if it still pulls, they can try switching the front tire & wheel assemblies. If still NG, then, if the front caster (well, no such thing as rear caster except on 4 wheel steering cars)–if the caster is adjustable, they can change the caster values from R/f to L/F in such a way as to overcome the pull, per 4450. Since caster is not considered a tire wear angle unless it’s out tremendously, this would be the way to go.
If caster isn’t adjustable they can still create a difference between the camber values R/F to L/F (to overcome the pull), but since camber is a tire wear angle, they’ve got to stay within each camber’s specification “window”. I used to do this all the time on Volvo P2’s. It’s easier than you think for halfway experienced alignment tech.
Good luck & post back!