vibration at frewway speed?
02-20-04, 06:01 PM
#46
A buddy sent this to me and I thought I would relay it as it has some relevance.
http://www.stoptech.com/whitepapers/...otors_myth.htm
http://www.stoptech.com/whitepapers/...otors_myth.htm
02-20-04, 07:08 PM
#47
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I have seen that article posted on many different forums. Myth Number 1 makes no sense to me. I have seen, and turned, many rotors that were warped. His explanations about cooling make sense, but the metallurgy part is crazy. Pad spotting on the rotors goes away in just a few miles. I have never witnessed the "deposits" he mentions. Wash the car, rust the rotors and notice that they rust EXACTLY as clean cast iron would rust, which is to say evenly.
Why is the industry so full of brake machine manufacturers if as he claims, rotors don't warp? Of course they do.
I wish the article would go away.
Why is the industry so full of brake machine manufacturers if as he claims, rotors don't warp? Of course they do.
I wish the article would go away.
02-20-04, 09:37 PM
#48
Browsing the net can really add confusion when write-up's are listed on such sites. Glad you responded.
I couldn't mount my dial indicator sufficiently and I got a reading of .004" on one side and .006" for the other. I believe that .002" is acceptable. I have to rotate the tires so we'll see if that ever so slight vibration goes away with mine. On a very smooth road (not that many in So. Cal) I can feel it, otherwise it is not obvious.
I couldn't mount my dial indicator sufficiently and I got a reading of .004" on one side and .006" for the other. I believe that .002" is acceptable. I have to rotate the tires so we'll see if that ever so slight vibration goes away with mine. On a very smooth road (not that many in So. Cal) I can feel it, otherwise it is not obvious.
02-20-04, 09:46 PM
#49
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Mike, under braking one might feel a .006 in run-out in the brake disc. It is unlikely anyone could feel a .002 run-out, and yes, most manufacturers put that amount within the acceptable range.
A road wheel can have .050 or .060 inch run-out (ten times) and still not produce a vibration under all conditions because the tire sidewall is able to absorb the deflection without passing it along to the body of the car. Out of balance, and tire carcass and belt problems will be felt more readily.
It takes a bit of work to get these cars right, but when they are right, they are VERY right!
SRK
A road wheel can have .050 or .060 inch run-out (ten times) and still not produce a vibration under all conditions because the tire sidewall is able to absorb the deflection without passing it along to the body of the car. Out of balance, and tire carcass and belt problems will be felt more readily.
It takes a bit of work to get these cars right, but when they are right, they are VERY right!
SRK
02-23-04, 11:05 AM
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Originally posted by LSPilot
BigDLexus:
Your problem sounds similar to what I had. I couldn't really tell there was a vibration on the concrete freeway near my house, but I could definitely feel it on smoother road surfaces. As a matter of fact, right after I changed the bushing, I went to test it on the concrete freeway closest to my house and I had trouble knowing if I had fixed anything. Later in the day, I went to an asphault freeway and then I knew I had it nailed.
How many miles does your LS have on it? What year?
It's a 99 LS400 w/ 60k miles. the dealer has gone over like there was gold hidden in it, and has come up with nothing but a bill for an alignment that I did or did not need. It was checked under warranty, so they wanted to find something wrong.
Does the vibe come in waves at all? Does the vibration change a little when you let off the gas or accelerate? Can you feel the vibration through the whole car, not just the steering wheel?
It is most noticeable when cruiseing down the interstate at steady speeds. almost only on blacktop. It doesn;t seem to come and go. I had a car that had bad CV joints, so I am familiar with engine/torque realted shakes.
It feels like it's the whole car, not only the steering wheel. If it where the steering wheel, I would know where my problem was.
The car is at the dealer right now for an engine problem, should I have them check to see if the tranny mount is still within specs? Or can they be trusted to be objective about it?
Thanks for the input-
BigD
-Josh
BigDLexus:
Your problem sounds similar to what I had. I couldn't really tell there was a vibration on the concrete freeway near my house, but I could definitely feel it on smoother road surfaces. As a matter of fact, right after I changed the bushing, I went to test it on the concrete freeway closest to my house and I had trouble knowing if I had fixed anything. Later in the day, I went to an asphault freeway and then I knew I had it nailed.
How many miles does your LS have on it? What year?
It's a 99 LS400 w/ 60k miles. the dealer has gone over like there was gold hidden in it, and has come up with nothing but a bill for an alignment that I did or did not need. It was checked under warranty, so they wanted to find something wrong.
Does the vibe come in waves at all? Does the vibration change a little when you let off the gas or accelerate? Can you feel the vibration through the whole car, not just the steering wheel?
It is most noticeable when cruiseing down the interstate at steady speeds. almost only on blacktop. It doesn;t seem to come and go. I had a car that had bad CV joints, so I am familiar with engine/torque realted shakes.
It feels like it's the whole car, not only the steering wheel. If it where the steering wheel, I would know where my problem was.
The car is at the dealer right now for an engine problem, should I have them check to see if the tranny mount is still within specs? Or can they be trusted to be objective about it?
Thanks for the input-
BigD
-Josh
02-23-04, 11:37 AM
#51
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BigDLexus:
With your car being so new and with so little mileage, I wouldn't put my money on the tranny mount. It sounds to me like you have a bad tire or wheel. Rice wrote an interesting diagnostic procedure for finding the culprit. Let me see if I can find it... Here it is:
There are many reasons why a car may vibrate. However, the most common or likely are wheels and tires.
I had vibration on my car and got rid of it.
Here's how:
The first thing I did was to balance all 4 wheels. That helped a little, but failed to eliminate all the vibes.
Then, I bought 4 new tires and balanced again. This was not too bad, considering that my old tires were... old. This decreased vibration, but not by much.
Finally, I realized that one ore more of my rims were bent. Since I couldn't just buy 4 new rims, I began experimenting by moving rims from front to back. I knew, that if that changed the way my car vibrated, then, in fact, those were the rims. That also gave me a hint of which rims were good and bad. Sure enough, when I switched the rims around, my vibration pattern changed. Now I knew that it is definitely one or more of my rims that are bent, since the rubber is new and balanced.
How did I figure out which rim is bent? Well, I got lucky there. Right at the time of my trials, my friend wrecked his 96 LS. So, I took his rims and began experimenting with the combination of his and mine wheels. Eventually, I got it right.
Now, I don't have any vibration at any speed
If I didn't have extra 5 wheels to play with, I would've just bought one new rim and substituted it for each of mine until I found the culprit. Those who have an unused spare, can use that to do the diagnostic.
From how you've described your problem and the age of your car, it seems like this would be your best bet at finding the vibration. Did the dealer check for lateral runout on the wheels? I would imagine if the previous owner hit a curb or a pothole hard enough it could ruin one of the wheels and cause such a vibration.
-Josh
With your car being so new and with so little mileage, I wouldn't put my money on the tranny mount. It sounds to me like you have a bad tire or wheel. Rice wrote an interesting diagnostic procedure for finding the culprit. Let me see if I can find it... Here it is:
There are many reasons why a car may vibrate. However, the most common or likely are wheels and tires.
I had vibration on my car and got rid of it.
Here's how:
The first thing I did was to balance all 4 wheels. That helped a little, but failed to eliminate all the vibes.
Then, I bought 4 new tires and balanced again. This was not too bad, considering that my old tires were... old. This decreased vibration, but not by much.
Finally, I realized that one ore more of my rims were bent. Since I couldn't just buy 4 new rims, I began experimenting by moving rims from front to back. I knew, that if that changed the way my car vibrated, then, in fact, those were the rims. That also gave me a hint of which rims were good and bad. Sure enough, when I switched the rims around, my vibration pattern changed. Now I knew that it is definitely one or more of my rims that are bent, since the rubber is new and balanced.
How did I figure out which rim is bent? Well, I got lucky there. Right at the time of my trials, my friend wrecked his 96 LS. So, I took his rims and began experimenting with the combination of his and mine wheels. Eventually, I got it right.
Now, I don't have any vibration at any speed
If I didn't have extra 5 wheels to play with, I would've just bought one new rim and substituted it for each of mine until I found the culprit. Those who have an unused spare, can use that to do the diagnostic.
From how you've described your problem and the age of your car, it seems like this would be your best bet at finding the vibration. Did the dealer check for lateral runout on the wheels? I would imagine if the previous owner hit a curb or a pothole hard enough it could ruin one of the wheels and cause such a vibration.
-Josh
02-28-04, 01:45 PM
#52
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Find a Lexus dealership or a Discount Tire, or any other reputable tire shop that has a wheel balancer made by Hunter Engineering called a GSP9700. This machine will road test the wheel and tire asembly off of the vehicle, and will tell the technician where to match the tire to the rim. This way, the assembly will roll as smoothe as possible. This machine will solve a ton of problems for a bunch of you guys here on the site. Check out this website for further information:
http://www.gsp9700.com
BTW, I used to sell this machine. It works wonders!!!!!
http://www.gsp9700.com
BTW, I used to sell this machine. It works wonders!!!!!
Last edited by kubys; 02-28-04 at 01:46 PM.
02-28-04, 06:42 PM
#54
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A little education about how the machine operates will answer your question.
You can just balance the rim and assembly, or you can "road test" the rim and tire assembly, then balance. The load roller applies about 1000lbs of force (it's been a while, if memory seves me correct), checking for tire uniformity. Then the roller is released and the balancing function takes over. If the tire is out of "spec", then the machine prompts the user to measure rim runout. The machine will prompt the user to mark the rim in 1 area, and the tire in another area. The user must then remove the rim and tire assembly from the GSP to a tire machine. He lets the air out, then rotates the tire on the rim. When this occurs, you now have a wheel and tire assembly that is as "round when rolling" as possible. You're taking the flaws out of the assembly when you match the 2 positions together. They cancel themselves out. Therefore, vibration problem solved. Then the tech must put the assembly back on to the machine, double check his work and then balance the rim and tire assembly. Simply put, you are matching the "hard" spot in the tire with the low spot on the rim. I guarantee if people perform this service, this would solve tons of vibration problems for everybody on this site.
The GSP as a wheel balancer makes it real easy for the user to apply stick-on weights as well. (Esp. for people who have chrome factory rims like myself) If you ever have this done to your car, ask to watch the tech. performing the service, and learn a little bit at the same time.
You can just balance the rim and assembly, or you can "road test" the rim and tire assembly, then balance. The load roller applies about 1000lbs of force (it's been a while, if memory seves me correct), checking for tire uniformity. Then the roller is released and the balancing function takes over. If the tire is out of "spec", then the machine prompts the user to measure rim runout. The machine will prompt the user to mark the rim in 1 area, and the tire in another area. The user must then remove the rim and tire assembly from the GSP to a tire machine. He lets the air out, then rotates the tire on the rim. When this occurs, you now have a wheel and tire assembly that is as "round when rolling" as possible. You're taking the flaws out of the assembly when you match the 2 positions together. They cancel themselves out. Therefore, vibration problem solved. Then the tech must put the assembly back on to the machine, double check his work and then balance the rim and tire assembly. Simply put, you are matching the "hard" spot in the tire with the low spot on the rim. I guarantee if people perform this service, this would solve tons of vibration problems for everybody on this site.
The GSP as a wheel balancer makes it real easy for the user to apply stick-on weights as well. (Esp. for people who have chrome factory rims like myself) If you ever have this done to your car, ask to watch the tech. performing the service, and learn a little bit at the same time.
02-29-04, 12:51 AM
#55
Pole Position
Interesting to read all the comments so far. My 92 with 167k has got vibration through the steering wheel between 40-60mph (which I know is the front wheels worn at the sides and out of balance). However, I have another vibration which affects the entire car. Funnily enough, even though it's there at lowish speeds too, it really kicks hard in at exactly 84mph. You can see the passenger seat headrest vibrating like crazy at that speed. You can't seem to drive through the vibration by going 100 or 120.
I've just changed the upper control arms and rear axle carrier bushes anyhow.
The garage here has suggested that it's the driveshafts that are causing the vibration throughout the whole car. Reading through the posts makes it sound like it might be the tranny mount.
Any suggestions?
I've just changed the upper control arms and rear axle carrier bushes anyhow.
The garage here has suggested that it's the driveshafts that are causing the vibration throughout the whole car. Reading through the posts makes it sound like it might be the tranny mount.
Any suggestions?
02-29-04, 12:20 PM
#56
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brit_lex:
My suggestion would be to definitely change your tranny mount. If you look back in the thread on pg. 3 you'll see a website link in one of my posts where you can order it. If you're a beginner-level mechanic like me, I assure you, the procedure is very simple-- and when you're done you'll feel like a stud because you've fixed a major problem without even really knowing what you're doing. Tell all your friends.
From what you've described, it sounds like the same exact thing I had. Change it and you'll probably say goodbye to that vibration altogether. Good Luck!
-Josh
My suggestion would be to definitely change your tranny mount. If you look back in the thread on pg. 3 you'll see a website link in one of my posts where you can order it. If you're a beginner-level mechanic like me, I assure you, the procedure is very simple-- and when you're done you'll feel like a stud because you've fixed a major problem without even really knowing what you're doing. Tell all your friends.
From what you've described, it sounds like the same exact thing I had. Change it and you'll probably say goodbye to that vibration altogether. Good Luck!
-Josh
03-01-04, 01:03 AM
#57
Pole Position
Thanks for the feedback. I'm definitely going to change the tranny mount then. I hope it's the cause.
However, I will probably will take it to the garage in the end to change the mount, as I don't have access to ramps myself.
Brit_lex
However, I will probably will take it to the garage in the end to change the mount, as I don't have access to ramps myself.
Brit_lex
03-01-04, 07:47 PM
#58
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Brit-lex:
I can understand why you'd take it in to a shop. You should have seen my neighbors faces when I drove my car up on ramps the other morning. I am fortunate enough to live in a very nice neighborhood overlooking the ocean. Unfortunately, along with the ocean view comes the snob-factor. I'm the only one on my block who washes his own car!! I suppose I could pay to get my car washed, but it's become a hobby for me...
Hope the tranny mount fixes your problem. Get it done sooner rather than later. I can't imagine all that vibration is very good for the car.
-Josh
I can understand why you'd take it in to a shop. You should have seen my neighbors faces when I drove my car up on ramps the other morning. I am fortunate enough to live in a very nice neighborhood overlooking the ocean. Unfortunately, along with the ocean view comes the snob-factor. I'm the only one on my block who washes his own car!! I suppose I could pay to get my car washed, but it's become a hobby for me...
Hope the tranny mount fixes your problem. Get it done sooner rather than later. I can't imagine all that vibration is very good for the car.
-Josh
08-23-04, 11:11 AM
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I've read this whole thread and I've got the same thing on my 95 ls400 w/ 88,000 miles. I'm curious about one thing, are you guys who have changed the tranny mount still happy with the smoothness or was it a temp. fix? I'm ordering one today as I think 9 years is long enough to warrant a new piece of rubber. Mine does the exact same thing. Between 30-45 mph under acceleration the car vibrates, then fades, then comes back at 70 - 80 mph. Tires are balanced and all, so that's been addressed. Also, any good info on changing the motor mounts? I'm betting those are getting close to replacement too. Although I've got lower miles than most on here, I'm still in thinking that time has played a factor. So, still happy?
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