Rotate Tires and Alignment

A quick summary of some of the things i've fixed on the 2005 Pontiac Grand Prix GTP in the past couple years:

• 2014 - Car Rear Hub Install - How To
• 2014- Replace Rear Struts - Again
• 2013 - Replace Exhaust
• 2013 - New Mufflers
• 2013 - Front Wheel Bearings
• 2012 - Replace Rear Struts
• 2011 - Broken Heads-Up-Display HUD
• 2011 - Fogged/Crusted Headlight Covers

I left off last time talking about my car, saying that i got a flat and when changing it, noticed that it was from the steel wearing through the rubber. 

It was on the tire that got dented from a pothole in February.  Several years ago i hit a pothole with the same tire.  Both potholes that i hit were less than 1 mile from our house.  The first time i just had to replace tire, the sidewall blew out, and the sway bar link, the bolt busing broke.  But the time in February, although the rim was dented everything else was fine. 

The car rode fine, although i did have to fill the tire up with air about every month or so.  I asked a couple of places and read online about anything i could do to fix the dent but there was no solution.  Steel rims can be reshaped into place, but aluminum cannot be rebent, it would crack and be no good.

It must have been a combination between a slightly flat tire and the dented rim which caused the uneven tire wear.  I was worried that it might also be a tire alignment issue.  Most things that i read online about uneven tire wear is from bad alignment.  But all the pictures of those tires are 1/2 of the tire worn and 1/2 of the tire in good condition.  My tire tread was completely fine, only the "corner" of the tire was worn.  It wasn't a common problem.

I looked online and a new/used rim for a Pontiac Grand Prix GTP Comp-G car was between $195 and $300, plus shipping.  It has to be a used rim because the car is from 2005 and Pontiac isn't even in business anymore.  So i wrote down the phone numbers of a bunch of tire places in the area that sold new and used rims.  Karrie ended up calling some of the numbers one day and she finally found a place that had the rim.  For $138 we got the rim and tire.

I didn't want to put the new rim on the front, so i decided that it was a good time to rotate the tires.

Here's a video of the whole rotating tires process.  But continue reading for all the pictures and descriptions of why i did what i did.

How to Rotate Tires the Right Way

http://youtu.be/KMhonCoJ_vA

I checked the owners manual for the Grand Prix and it showed the correct rotation pattern.

The front tires went straight to the back, the back tires crossed sides to the front.  This was one of those times that i was glad i have 4 jack stands.  I started by jacking up the car at each wheel and putting it on a stand.  Then i just went about rotating the tires as shown. 

I was surprised when i removed the other front tire and saw some of the similar tire wear as the other front tire.

The back tires were perfectly fine.  In fact they had basically the same amount of tread on them as when they were new. 

Here you can see the hole in the tire.

It must be that because the car is front wheel drive it puts more force and more strain on the front.  That combined with the fact that the front tires are doing the turning as well.  So i moved the rear tires to the front and vice-versa. 

The car rode fine but i felt a slight vibration.  I wasn't sure if it was an unbalanced wheel, alignment issues, or just because i put newer tires on the front.  I didn't want the same thing happen to the new tires i put on the front, so i took it into the shop to get an alignment.  I did see a few video's on Youtube about how you can do an alignment yourself.  It involved very precise measurements using a string pulled tightly parallel to the tires.  After watching some of them i didn't feel confident in doing it correctly.  There was lots of measuring to arbitrary points on the rims. 

I'm glad i took it into the shop.  Beyond balancing the tire, they had a machine that used lasers to check the tires alignment, camber, and caster.  And everyone knows that anything that uses lasers is way better then something using a string.  For $80 they adjusted the rotation and twisting points of the tire until they were in their correct specifications. 

I was surprised to see that the front tires were fine, totally within the range of acceptable values.  But it was the rear tires that were out of alignment.  Then i remembered that i had changed the struts twice in the rear and changed one of the hubs.  I don't think it was hub, because i have also changed the hubs/wheel bearing in the front too.  So it must have been the minor change in the rear strut location when i changed them that caused the tires to be slightly misaligned.

After everything was fixed the car seems to ride better.  The vibration was gone, but that was probably the result of the unbalanced tire.  Mainly it's just peace of mind knowing it's all good and the new tires on the front shouldn't wear out like the other ones did.