SuicidnS13

iTrader: (2)

Well the front end def feels better. Tighter all around is the best way to describe it. But as soon as I hit highway speedsI still have the same shake. I had the shake with a previous wheel and tire setup. When I recently had new wheels and tires mounted it was almost non existent. Had an alignment done and little by little it got worse. So I figured it was from uneven tire wear from worn strut rod bushings. Well after pulling them out and going with polys the old ones didnt look that bad really.

Next up will be a tire flip and balance. Or maybe new tires if these somehow got cupped. Would motor mounts cause this? I feel it in the floor and steering wheel.

PureDrifter

iTrader: (10)

check the rear tires and carrier arms. But i'm more inclined to say this is a tire issue if the vibration is speed dependent.

johnnyg66

Tires maybe my fronts had gotten worn from old ball joints and stuff. Moved them to the back till i got new tires. But always had some vibrations at upper speeds not too bad. After i did motor mounts it all went away.

RA40

iTrader: (6)

With PD, tire issue. As they wear, the balance changes slightly over time. On the LS, they can be pretty sensitive to tire balance.

door331

Following to hear results- I have a similar vibe issue I am trying to track down.

NetG

how do your axles look? Highway speed vibs are usually caused by rotating parts but you seem to have about eliminated all of them. With an alignment done that should have eliminated the suspension from the list of suspects unless your ball joints are shot, have you replaced anything other than just the strut rods?

SuicidnS13

iTrader: (2)

Well my tire guy was not in today. So tomorrow Ill be flipping my tires and a rebalance. If that doesnt smooth it out. Then Ill be ordering new tires just after my alignment is done this weekend.

I have changed out the Transmission Mount and now the front strut rod bushings. I went with Polys as well I prefer the tighter feel in the front, plus I drive real low even on air suspension. This vibration has been with me ever since the car has been dropped on coilovers and been on aftermarket wheels. It went away with my new Weds and tires mounted in Jan/feb but my alignment was off and I went through the fronts pretty quickly. Had an alignment done and replaced the fronts and again she was smooth for a short while.

Now I know my alignment is good and even have minimal camber wear in the front as compared to before when I had bad alignment. So i figured I must be wearing them in an uneven fashion. It hard to tell that unless the car is on a lift etc. Well, according to search results uneven tire wear comes from worn strut rod bushings. Changed them and the transmission mount. Def a smoother ride all around until the same highway speeds. But def not as bad as before.. So at least I know I am moving in the right direction here.

SuicidnS13

iTrader: (2)

If it matters I have 106,000 miles on her now

and if you havent seen her

http://www.flickr.com/photos/suicidns13/9294092170/http://www.flickr.com/photos/suicidns13/9294092170/ by http://www.flickr.com/people/suicidns13/, on Flickr

SuicidnS13

iTrader: (2)

So here it is guys... my rear tires had cupped... more than likely from being Nankangs as they have soft tread rating too. Got new tires, less stretch and rides smooth as butter again, with a sportier steering feel due to the strut rods being poly. Sure some creeking here and there, but my car is vipdout... not trying to ride around like a stock lexus LOL...

SuicidnS13

iTrader: (2)

Also what can cause uneven rear tire wear? Assuming alignment is on point still.

LScowboyLS

with your tires all cambered up to the ridiculous, I know you did not just ask that question - lol

SuicidnS13

iTrader: (2)

Cupping is not caused by camber LOL... Cupping is mainly caused by Cheap Tire Construction or Toe if it is in the rear of a car. Ive had tons of cambered cars and the LS is the first car Ive had cup 2 sets of rears tires.... both were Nangkangs how ever. I am going to assume that it is because of their soft tread rating. My alignment was on point. Unless there is another reason for irregular tire wear on the rears of LS400's that we are obviously unsure of.

LScowboyLS

Nangkang = cheap tire construction

if you want cheap tires that are made pretty darn well, look into Fuzion Touring

PureDrifter

iTrader: (10)

fuzion in my experience are total and complete crap.
edit: I ran ZRi's.

LScowboyLS

Fuzion tires are made by Bridgestone, they are not complete crap, they are what they are, which is a good $50 - $75 tire

Now of course, they are crap compared to a great tire like a Michelin Primacy or Pilot, or a Bridgestone Serenity Plus etc. or other world-class tire, but for a sub-$75 tire they are pretty amazing.

and apparently, I am not the only one who thinks so, as an example, on the largest database of tire reviews in the world, at tirerack.com - they score a 7.97 average user review with over 70 user reviews, which is pretty impressive.

For the right application, they are a great deal, I once had a 300ZX that the springs were completely shot to the point that I was doing the cambered tire thing without even wanting to, and tires were getting eaten up on the inside to the core in 5000 miles and I needed something safe and cheap until I could get time to replace the springs, and a pair of $55 Fuzions were just the ticket!