: Alignment Question - oblong bolt holes



iametarq
08-11-11, 06:23 PM
I took my wife's Seville in today for tire rotation and alignment, we found that the front right wheel was out of alignment and the edge of the tire is chewed up. Luckily all 4 need to be replaced anyway.

However, in order to fix the alignment, they called to say the strut bolt holes where the strut mates with the steering knuckle needed to be made oblong. I have the OEM AC Delco struts and they are worn out again, so I said go for it, since I will probably replace them eventually. They were shocked I had OEM struts, but I told them they are the 2nd set, not originals.

Does this mean that something is wrong with this strut? Or is something else wrong in the suspension? I recall reading here that our Sevilles do not need alignments because of the "net build" theory.

I'm not upset I just would like to understand how it all works. They also said that after market shocks have larger bolt holes to allow for alignment adjustments.

Thanks

Dadillac
08-11-11, 10:23 PM
Our cars do have the net build suspension. Aside from toe adjustments we do not have any alignment capability. If the suspension is out of alignment you need to find the worn part and replace it. It can be control arm related (bushings or ball joint) or strut mount/bearing. Or it could be a bent part. Oblonging the strut holes may get you back in alignment, but the offending part will still be worn out. I will assume that when you say the edge of the tire is chewed up you mean the inside edge. I would put my money on the control arm bushings being worn. You will need to replace the entire control arm as the bushings are not sold separately. I bought control arms from Rock Auto and got them rather cheaply. You WILL NEED the GM ball joint separator to remove the spindle. I do not remember the part number but it is in the repair manual. I bought a good used one from Ebay for around $25 or $30 if I remember correctly. Good luck and post back what you ended up doing

Don

iametarq
08-12-11, 09:57 AM
Thanks, Don, that helps, but now the issue is that the lower Control Arms were both replaced in 2010. Is the one on the right bad?

Submariner409
08-12-11, 05:08 PM
This is just a guess - but if you were to install Ac Delco struts, the "net build" would probably come into play. There's a chance that the aftermarket struts (?) need some "tweaking" to get within specs. As you posted, the second set of AC's didn't require filing. Suspension bushing(s) shot ?

Somewhere, in the GM service manual there's a description of how to file the upper strut tower bolt holes oblong in order to correct one alignment problem - caster or camber - I forget which.

Whoops ! Don beat me to it.............

iametarq
08-13-11, 12:56 AM
Got it that makes sense. Instead of making the bolt holes on the bottom of the strut oblong, do it at the top there the 3 strut mount holes are? Well If I ever go with the RSS type struts again in the front I'll have a GM dealer do the alignment this time.

However, as of today there are 194,000 miles on her and I'm not sure I'll go RSS AC Delco struts again. :) With my luck something will happen to the car 4 months later!!

johnny kannapo
08-13-11, 09:29 PM
The bottom bolt hole in the strut is oblonged a small amount to make the camber ajustment.
The lower strut bolt will swing a small amount & the knuckle surface is serrated for positive secure clamping.

http://i826.photobucket.com/albums/zz183/billytheshoe/a%20%20suspension%20album/100_2214.jpg

Dadillac
08-13-11, 10:38 PM
Thanks, Don, that helps, but now the issue is that the lower Control Arms were both replaced in 2010. Is the one on the right bad?
I wouldn't think the control arms are bad in only a year. I would suspect the strut mount. Did you change the mount when you installed the struts?

Don

iametarq
08-13-11, 11:16 PM
I did install new strut mounts when I installed the struts, but again that was 90,000-100,000 miles ago.

Dadillac
08-14-11, 08:06 PM
Mark the only other thing that it could be is the tie rod ends. If your toe is out of adjustment it will cause a cupping on your tire edges. It shouldn't cause uneven wear as in the outside of the tire has a lot of tread while the inside is almost bald. What type of tire wear do you have?

Don

iametarq
08-15-11, 02:56 PM
The outward facing edge of the tires are worn. I'll get a picture of it tonight.

I cannot believe I didn't notice it before, but then again, it's my wife's car and the garage is a dark cavern.

Submariner409
08-20-11, 12:38 PM
If the outside 2 or 3 tread bars are worn excessively it's due to either too much toe-in or underinflation coupled with hard cornering.

There are some pretty good line drawings of different types of tire wear and their causes in the GM (and most other) service manuals

iametarq
08-21-11, 10:25 PM
Thanks folks, I'll do some research in the book for the pictures of tread wear and make sure everything is the way it should be before I get new tires this winter. I try to be religious on tire pressure, but I don't have a compressor yet in my garage and the wife tends to be the one to fill up the tank.