Alignment question

That was no technician.

A competent technician who understood wheel alignment could have properly set your alignment using some string, stands, a level and a tape measure for checking alignment. It's not rocket science.

The important thing is to find a shop with a tech that knows what he is doing, not just a partially trained shop simian.

 

Using shims to correct non-adjustable rear suspensions is a very common practice. The Hunter Winalign software will even tell you exactly how to cut the shim to achieve the desired correction. All you need are the shims, a pair of cutters and common shop tools. Shops make a killing by charging for the shim and 1/2 hr labor per wheel so I don't see why your shop is passing up the opportunity that is a win-win for both parties.

Find another shop.

 

Why rotate? It's safer to keep the less-worn tires at the rear at all times to reduce the chance of oversteer ("fishtailing"). If you take this approach you will be buying tires two at a time because the front pair wear significantly faster than the rear.

 

Just wanted to say a big THANKS to you all. This thread is very helpful to me. My right rear is wearing out faster than the others.

 

Unless your tires are wearing with identical patterns on all 4 tires, when you move your rear tires that have thoroughly worn in on the rear, they won't be making even contact pressure with the ground in the front. They will wear faster and have an adverse effect on handling.

If you are planning on going to a different make or model of tire, then not rotating tires is also a bad idea. When you have different makes/models of tire front and rear, you can end up with the rear being the weak link even if the rear tires are the new ones. That's not just because of tire quality, you can have higher quality tire in the rear that has more flexible sidewalls and end up with a treacherous feeling combination.

One thing in favor of not rotating tires is that you won't be hiding alignment problems with frequent rotations.

 

I prefer the later! I prefer buying two at a time and correcting the problem if they are wearing prematurely. That way I don't prematurely wear all four. Only my opinion. Hal

 

Interesting point, but wouldn't that indicate an alignment problem that should be corrected? Maybe I've lucked out 'cos mine wear quite evenly.

 

Old thread, I know.

My Prius has 160k on it, and I finally bought 4 tires at the same time. This allowed me to be able to get an accurate 4 wheel alignment. I went to a local shop, and they told me the front was perfect, but the back had 0.37 and 0.36 alignment, which was beyond the 0.03-.0.30 range. Funny how both side were off almost the exact amount. However, I didn't do the alignment at this time because my tires have always worn evenly, both front and back. My car also goes straight if I take my hands off the wheel, so this is the other way I determine if I need an alignment (the 1st being tire wear and noticing any vibration).

At some pint I will get my shocks and struts done, and this will be when I get the 4 wheel alignment done. The shop did mention I would need a shim kit for the rear, as it is non-adjustable, and quoted $20 for a shim kit. The labor was 3 hours for both back wheels, maybe a little high.

So, if your car does not shake, and the tires wear evenly and it drives straight when you let go of the wheel, perhaps you don't need an alignment? I am not getting one at this point, maybe at 180k?

David

 

I assume you are citing the toe-in measurement. If so then your rear tires have excess toe-in. This helps vehicle tracking but means that rolling resistance is slightly more than it needs to be. If the toe-in was reduced then you might get slightly better mpg.

 

I have had a set of tires on mine for about 25k. I noticed the outside of both front tires were wearing more rapidly than the rest of the tire. I took it to a shop and they said the alignment was fine and sometimes tires will do that. I call BS but left and will never return. How can I tell if they are actually out of alignment? I don't trust any of the parts changers that call themselves mechanics nowadays. There are few good mechanics left but majority don't have a clue.

 

Yes, if you find that the front tire outside tread is wearing more rapidly, either your front axle has excessive positive camber (which means that the top of the tire is leaning out to the side of the car more than the bottom, and this can be adjusted) or you are taking corners at excessive speed.

It is pretty normal for the Prius to show excessive tire shoulder wear (on both the inner and outer shoulders) if the manufacturer recommended spec of 35/33 psi tire inflation is used. Hence I use 44/42 psi and get even tire tread wear. A side benefit is slightly reduced rolling resistance which results in improved mpg.

 

Hmmmm.... I will increase tire pressure to see if that helps.

Thanks

 

I had one of my seconds gen Prius making excessive tire noise. So when I went to have the tires rotated this only made the problem worse since the "cupped" tire from the mis aligned rear, was now in front.

I end up having to replace one of the tires (which) still had plenty of tread on it with a new tire and had to get a 4 wheel alignment and have the rear shimmed. The car rides much better with far less noise.

 

One quick question about the rear axle. ive been reading up a lot about this. last year I rotated the tires on our 08' and noticed the rapid thumping from the scalloping of the tires. (didn't realize front to back same side only). after the cross rotation of tires, the car now needed to be turned to the left slightly to track straight. I thought that was odd and finally got it to an alignment shop where they told me they couldn't align it as they didn't know how to disable the electric part. Wth! anyway, (didn't get a printout like I should have) brought the car home and have been driving this way for almost a year. when I rotated the tires I used ramps then floor jack to get front off ground. used rear axle to lift rear (a big mistake on my part I think) it looked sturdy enough. we just purchased a new set of the Michelin OEM replacements. I guess my question is how much bow or arch does the rear axle have stock and did I do harm to it? ive measured from the front of the wheel well to center hub and drivers side is 14" and pass is 13.75". It seems either I bent the rear axle slightly or its mounted crooked? I don't want to ruin these new tires prematurely so ill be getting the car to an alignment shop soon and picking up the shim kit. any thoughts/ideas would be appreciated, thanks!

 

if you jacked it up on the rear axle, you most likely bent it. if its bent, you got to replace it. it could be unsafe, and will ruin tires.

 

I once tried to jack my Prius up with my floor jack, right in the middle of the rear axle - I didnt even get the rear wheels off the ground, until I saw the point where you are supposed to jack it up by. However, I noticed my rear axle had a bow in the middle and wasnt sure if it was there before or not....

Well I have since looked at other Prius rear ends and noticed that it is normal. I will take a picture tomorrow, bl817 and post it.

 

cool, thanks, I had ours up on the ramps looking at it and seems fine with just a slight bow in it. still going to the alignment shop and shim kit on the way.