Car Is Shaking When Decelerating.

[calean007]

I have a 92 LS 400 and recently, we replaced the 17 inch rims and tires back to the factory 15 inch size. After about 3 days of driving it, it was shaking when either letting off the accelerator or hitting the brakes, especially when they are hit hard. Now I took it back to the tire shop and the balance was off and they fixed that. However, the problem has returned and is getting worse I believe.

I don't think this is warped rotors or anything like that and when cruising, the ride is smooth. Could it be that I need an alignment? I had one done last year, but that was on bigger rims and tires? Does it make a difference?

[lovlex]

sounds like rotors

[ArmyofOne]

I have a 92 LS 400 and recently, we replaced the 17 inch rims and tires back to the factory 15 inch size.  After about 3 days of driving it, it was shaking when either letting off the accelerator or hitting the brakes, especially when they are hit hard.  Now I took it back to the tire shop and the balance was off and they fixed that.  However, the problem has returned and is getting worse I believe.

I don't think this is warped rotors or anything like that and when cruising, the ride is smooth.  Could it be that I need an alignment?  I had one done last year, but that was on bigger rims and tires?  Does it make a difference?

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You are in denton? Im in Ft worth LOL, there is a meet coming up, check here:

http://www.clublexus.com/forums/showthread.php?t=151907

I would say more than likely its your rotors.

care to let me take a ride? i would be happy to ride along if you want to meet me somewhere.

EDIT: Oh BTW, ifyou were driving through watauga on Denton HWY, then dont worry about it, its the road. that road has all kinds of washbaords in it.

[VBdenny]

You said you put the original 15" rims back on. The rims are two left side rims, and two right side rims. It can cause the brakes to overheat if you have them reversed. They are marked.

[calean007]

You said you put the original 15" rims back on.  The rims are two left side rims, and two right side rims.  It can cause the brakes to overheat if you have them reversed.  They are marked.

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Sorry mate, should have been more clear. I meant the original size, not the original rims themselves....sorry..

Well, if it's the rotors, am I looking at brand new rotors, or can they be machined out?

[Econ]

If it is the rotors, you'd have to ask the guys at the shop you have them machined at. They'll be able to tell you if it's too far out of spec to have them machined.

That said, I generally just replace warped rotors whether they're willing to mill them or not. Seems kind of like asking for trouble if you put rotors that have already warped back on. Just my $.02.

[calean007]

If it is the rotors, you'd have to ask the guys at the shop you have them machined at.  They'll be able to tell you if it's too far out of spec to have them machined.

That said, I generally just replace warped rotors whether they're willing to mill them or not.  Seems kind of like asking for trouble if you put rotors that have already warped back on.  Just my $.02.

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Shall I go ahead and assume that new rotors for a Lexus are not cheap....

[Econ]

About $100 each for the front rotors from www.discounttoyotaparts.com, and $145 each for the rear rotors.

I never noticed a big difference between rotors from OEM distributors and Autozone or Checker, frankly. Look at the venting in the rotors from the discount auto parts places and you'll probably see what I mean. There's just not much that can vary unless you replace it with an aftermarket setup.

[lex4me]

I had nothing short of a miserable experience with non-OEM rotors that were not Wagner's with warping, etc. I put the Wagner's on from O'Reilly's and life has been good ever since (well, except for a sticking front caliper).

[calean007]

Here is something I failed to mention about this issue.

Before getting the new rims and tires, this vibration on braking never was present. It was only after they put the new rims and tires on that this started happening.

Now I've been told that it could be a problem with the tires steel belting or it could be a bent rim, even if it's ever so slight.

I'm taking it back to discount tire company in the morning and I'm going to have them ride along so they can experience it themselves. I just have a hard time believing it's the rotors, because if it was, I think that problem would have been happening before the tire/rim change out. I'm not trying to be an !Removed! to those who've suggested otherwise, but I did leave out this detail. When this vibration started happening, it was within days, not even a week after I got the new stuff put on.

[dave94ls]

You said you put the original 15" rims back on.  The rims are two left side rims, and two right side rims.  It can cause the brakes to overheat if you have them reversed.  They are marked.

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Sorry mate, should have been more clear. I meant the original size, not the original rims themselves....sorry..

Well, if it's the rotors, am I looking at brand new rotors, or can they be machined out?

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you would need to take them to a parts store so they can put a micrometer on them to determine if there is enough metal to be scraped off.

just from what you said about the symptoms i would say it is 100% rotors

hard deceleration can illicit that type of symptom.

best fix= new rotors and pads, i would advise against turning the rotors and not throwing new pad on it.

Dave

[Neo]

Just one more thing to check. I had originally thought you put back the OEM rims but if not, are these rims hubcentric? Is there any vibration at any speed while driving? Rotors would have been my first guess too but since it has been hashed, I thought I'd suggest something else. ;)

[jadecuir]

I'm having the same problem with my truck. Bought new tires, and got vibration between 55 and 65 mph. Took it back and they rebalanced one wheel. Said that a weight must have fallen off. drove away, same vibration. Felt like left front, could feel it in steering wheel.

So, I rotated tires, front to back. Now the vibration is felt through the seat. I checked runout on the rim and tire: rim= negligible; Tire= .125".

I think the tire is crap, out-of-round/ecentric.

[calean007]

Well, I took it in today, and it was only out about a quarter on balancing. no belt wear or anything like that.

I will be bucking up the cash for new rotors. Thankfully, the brake pads are still very much good so rotors is all that needs to be done...

I have have a mind to do it myself, but since these are anti-lock brakes, I don't know if there is more involved than just using a ratchet?

Thanks for those of you all along saying it was rotors, and not flaming me for being in denial...

[kzam02]

I had the same problem. I bought cheap tires at wheelworks which were 15s and my earlier tires were 16s. As soon as I changed the tires i felt the vibration. A friend of mine had some 16s so i took those from him and installed it and now the vibratiion is gone. Due to the weight of ls400, 15s can't handle it. Although the rotors might be the cause also, but if you had bought cheap 15s from a discount outlet most probably it is the tires that is causing the vibration... GOOD LUCK...