jmdettmer

Ok i'm desperate here. Since the beginning of summer i have felt a vibartion in my 98 GS400. I've had it up at Tom Wood Lexus at least five seperate times trying to identify a problem. We've swapped the wheels and tires and the driveshaft with another GS's and vibration still there. They installed new hubs on the front as well as lower ball joints. It's been aligned and tires are brand new and rotated and balanced. They also replaced the motor mounts and transmission mounts. The vibration occurs at all speeds but i especially notice it on the highway at greater speeds. It feels like during accel the vibration goes to the rear of the car and on decell it goes to the front. I can feel the vibration in the steering wheel although it's not always strong enough to were it actually shakes the wheel but does sometimes. If you set a can or a bottle water in the cup holder you can watch it vibrate and shake at all times while the car is moving. It's almost feels like my tires are bouncing around while going down the road. Tom Wood Lexus was confused to the point that they called down an engineer to look at it. He said to balance the tires and align it....they did so and said it went away and gave the car back to me, but it is still doing it. They said the wheels i had on the car wouldn't balance a tire quite right and that was most likely the problem....I just ordered brand new wheels custom made to fit the car and threw them on, the vibration is still there. I took it back to Lexus today and the service manager basically told me that there's nothing more he can do and that they've spent too much time already with my car and that i'm pretty much on my own!!!! What the F*** are you supposed to do when the #1 Lexus dealership tells you they can't help you. So now i'm on my own and just going to start replacing parts until it's fixed. I've ordered a brand new Tein C/S Coilover system for the car thinking it's got to be the suspension due to poor ride quality. PLEASE any comments are much appreciated. thanks

BayAreaLex

These 2GS cars are all around pretty impressive, but for F sake, there are just far too many complaints about vibes. I've been chasing a steering wheel vibe for the past three months and finally got about 80-90% of it cured... I will get to that later.

First, the dealerships hate hate hate vibe problems, AC problems, and wind noise problems because they often have trouble pin-pointing the culprit, it ends up costing them too much time/money, and they run the risk of replacing something that doesn't cure the problem and the end result is an unhappy customer. It's not uncommon for a dealership to try a few things and then turn you away. Common but sad. You'd think they would have enough pride in their product/service to have some escalation system in case problems aren't obvious. But we can wish forever. Onto your vibe problem.

First, usually you want to at least narrow down whether it's a front problem or a rear problem. Typically if the problem is with the fronts, you will feel it in the steering wheel. And if the problem is in the rear, you will feel it in the chassis, but that rule isn't necessarily true 100% of the time.

Most of the time vibrations are a result of wheel/tire imbalance. You mentioned that the original wheels had new tires and were balanced. Were these OEM wheels with a 60.1mm hub diameter? Are your wheel studs stock? And your new wheels, what's the hub bore and are you using hubcentric rings? I am sitting on non-OEM wheels and the hubcentric rings helped my vibes out significantly. And hopefully your new wheels aren't cheap replicas.

You can also check to make sure that your wheels/tires are not out of round. You can put them on a balancing machine and put your eye level in line with the top of the tire. If there is any "hop" you will see it. You can do the same thing with the side of the rim looking straight down. You will immediately see if the rim is walking sideways as it spins.

Another thing to look at that often gets overlooked is the caster arm bushings. There is post after post after post on this forum that describe vibes being drastically reduced when these bushings were replaced. I recommend the poly bushings from Sewell Lexus. I just installed these and am happy with the road feel and stability.

You mentioned poor ride quality. Why? It sounds like your car is stock? What's contributing to the poor ride quality? I hope you are separating the vibes from the ride quality.

Before we go any further, confirm that you've at least tried a set of Lexus wheels with a 60.1mm hub bore and let's rule that out first.

For my car (had a steering wheel vibe) the following had the biggest effect - Tire balance, hubcentric rings (I am on BMW Style 95 wheels), and poly caster arm bushings... The vibe was driving me insane. Now I got a handle on the problem with the items above and I think after an alignment I should be good to go.

Be careful about throwing coilovers on it until you have a handle on the problem.

newgsman

iTrader: (4)

I have done most of the regular stuff - ball joints, caster arms, control arms, tie rods etc and the car is pretty good but I would still get intermittent vibration. It occurred most often when driving first thing in the morning, after a few miles vibration would subside to almost nil. Last week I checked out my brakes and noticed that the slider pins were mostly seized. I freed them up an lubed them thoroughly. The car has been remarkably smooth since then.