Front Wheel imbalance in my LS at speed

[LS1BMW0]

Has anyone had any success with getting their dealer to correct a front wheel/tire imbalance that occurs between 60 and 80 mph in their LS? I've taken mine back to my dealer twice to correct (Rancho Ford/LM) and both times they've rebalanced the tires, checked the alignment, then proceeded to lower my tire pressure from 35 to 30 psi. I didn't buy this car for ride comfort but for performance. The rebalancing that they did appears to make the original vibration that occured at 80 seem worse now.

[351CJ]

LS1BMW0: Do you have a sport or non sport, V6 or V8? There was some discussion on this in Edmunds. Some of the cures were:

1. One person got the tires replaced by dealer.

2. Another had dealer re-balance, no improvement, took to a high end tire shop they rebalanced and ended up with less weights tires are fine now.

3. Other poster gave up and put Michelins on his LS, he's very happy now.

My LS (non sport V8, Firestones) has a slight vibration at 73 MPH and up.

[Lscman]

Tires can be out of round or out of imbalance. An out of round tire can not be corrected and it's wobble can be seen on a spin balance machine. An out of balance tire that requires more than about 0.5 oz or 15g weight added will go in and out of balance as speed changes. Look at the weight sizes and if they are over 0.75 oz or about 20g, insist on another tire at a firestone dealer or the auto dealer. Either should cover free replacement. Rotate the tires front to rear to isolate the problem. Are you sure it is not when the brakes are applied, that points to overheated rotors?

[This message has been edited by Lscman (edited March 21, 2000).]

[351CJ]

LSCMAN: How are wheel weights labeled these days? My weights have 5, 15, 30, 30 stamped on them. At first I thought these were grams but they seem big for grams could they be .5, 1.5... oz?

There was also a discussion on Edmunds about tires that are molded in clamshell verses segmented molds. The majority opinion was that segmented mold tires (Michelin) are usually more round and have less of a tendancy belts to get ripples in them which also can cause vibrations.

[Lscman]

It varies, but a 30g weight is about an ounce and 1" long or slightly more. 454g=16oz, if I recall. Grams are the more popular designation for weights these days.

[This message has been edited by Lscman (edited March 22, 2000).]

[351CJ]

Thanks for the info. The weight that has 15 on it is 1.5" long and is fairly thin. The weights that are marked 30 are 2" long and are much fatter than the one marked 15.

1 oz. = 28.34 g. which means 1 lb (16 oz.) is 453.6 g as you listed in your post.

I don't want to remove one of the weights to measure it, but the ones marked 30 seem too big to be 1.06 oz of lead.

[LS1BMW0]

Thanks to everyone for their advice! Because of the comments I was able to convince my dealer to replace all four of my Firestones for new ones. Not bad for 12,000 miles. The vibration seems to have gone away for now. Took the LS8 for an inaugural drive on Ortega Highway in Riverside County, CA and promptly dusted off a BMW325i. Don't think the driver was too happy about being left in the dust by a Lincoln!

[351CJ]

Hey LS1BMW0 - go hunt some 528i's now. May 2000 C&D has the following #'s:

test LS8 528i
0-60 7.5 7.8
0-100 20.3 23.0
0-130 35.1 sorry limited to 128
5-60 7.7 8.1
1/4mi 15.7 16.1

Don't understand the 1/4mi, several LS owners have taken their LS8's to the drags and consistantly done low 15's