theBun

I am hoping that someone in this group has had a similar experience and
will be able to help?

The short version:

Bought used Elantra 15,000 miles. Other than clacky valves when first
started, there have been only two problems.

1. Brake pedal pulsation

1a. This was corrected by taking a light cut off the rotors. There is,
however, a noticable "shudder" (Hyundai's word for it is "judder") when
applying the brakes at 70mph and slowing down to, lets say, 60mph.
No pedal pulsation. More of a chassis pulsation cause by one of the
rotors having large hot spots.


2. Steering wheel shimmy between 65 - 80mph.

2a. Had the original Michelin MXV4's road force balanced and match
balanced on a GSP 9700. Got it to inprove some, but not enought to
satisfy me. Three of the four steel wheels had lateral run-out greater
than .040". Replaced the wheels with MB 177-5703C Chrome wheels. All
four of the new wheels had -0- lateral run-out and at most .002" radial
run-out. They balanced out like a dream. There was some RFV which we
reduced by repositioning the tires for the front. The existing
Michelins where put back on the new wheels in radom order (i.e. not in
the same position they came off of. Test drive gave me extreem
steering wheel shimmy. So, OK the tire are toast and I have a really
nice set of chrome wheels. Replaced the tires with a set of Michelin
Destiny's. These are really nice tires sold by Discount Tire Company.

After replacing the tires 90% of the shimmy is gone. For some average
drivers this may not be a problem for them.

While the my car was on the lift I had the technician run it up to 80mph
without the tires and wheels on. We could feel the remaining vibration
start at 65mph and fade away at 80. Perhaps the frequency was just to
high to make it noticable at that speed. The vibration was strong
enough that I could feel it in my arm that was resting on the roof of
the car as well as on the lift it self.

Now the question is what components and in what sequence do we start
eliminating front end items. I think i would start with measuring the
rotor run-out on both rotors first. After viewing the TSB and service
info at Hyundai's Tech Web, there are other possibilities such as
scratched wheel bearings, CV joints, dynamic damper in the drive shafts.
(not sure if my version has these or not. Good news is the service
manager at the Hyundai dealer has agreed to work with me to try to
locate the problem.

Has anyone had a similar experience and found a solution?

Thanks you.

Paul
theBun
remove NOSPAM from my return address if replying to my email address

Mad Moe

On Sat, 08 Nov 2003 00:13:36 GMT, theBun <bun@NOSPAMcitlink.net>
wrote:

The short answer is to replace NOT turn the rotors , the production
run of OEM rotors are pretty crappy from that period . Hot spot
warpage can't be fixed by turning the rotor . I had same problem and I
only got it fixed by replacing them .

Mad Moe
madmoe1.nospam@cco.net

theBun

Mad Moe wrote:
> On Sat, 08 Nov 2003 00:13:36 GMT, theBun <bun@NOSPAMcitlink.net>
> wrote:
>
> The short answer is to replace NOT turn the rotors , the production
> run of OEM rotors are pretty crappy from that period . Hot spot
> warpage can't be fixed by turning the rotor . I had same problem and I
> only got it fixed by replacing them .
>
> Mad Moe
> madmoe1.nospam@cco.net

This is exactly the feeling I am left with. I think if I were to mic the
rotor thickness (or possibly lay a good straight-edge on the left rotor
surface it would show that the rotor is thicker in some area. This
could cause the rotor to be out of balance radially enough to give the
slight vibration. It feels like this is the case when i brake fro 70
down to 60, although there is no pulsation in the brake pedal that is
noticable.

Would it be best if I have them replace the pads as well so that I can
"break them in" as a package?

Thank you

Paul

Dances With Crows

On Sun, 09 Nov 2003 13:31:29 GMT, theBun staggered into the Black Sun
and said:
> Mad Moe wrote:
>> The short answer is to replace NOT turn the rotors , the production
>> run of OEM rotors are pretty crappy from that period . Hot spot
>> warpage can't be fixed by turning the rotor . I had same problem and
>> I only got it fixed by replacing them .
[snip]
> Would it be best if I have them replace the pads as well so that I can
> "break them in" as a package?

Depends. If the brake pads are worn out or close to it, replace them
along with the rotors. If not, you can save a few bucks by leaving the
old pads on, though you may want to look at
http://cartalk.cars.com/Columns/Arch...ctober/09.html for the
downside.

--
Matt G|There is no Darkness in eternity/But only Light too dim for us to see
Life is a persistent hallucination, Death a mere illusion.
Taxes, however, are Objective Reality.

Chuck

I had a Datsun 280Z a long time ago that had that problem. There was
something on the car (not the wheels) that was out of balance, so I always
had to have the wheels balanced on the car.


"theBun" <bun@NOSPAMcitlink.net> wrote in message
news:QyWqb.99$hw.97@news01.roc.ny...
> I am hoping that someone in this group has had a similar experience and
> will be able to help?
>
> The short version:
>
> Bought used Elantra 15,000 miles. Other than clacky valves when first
> started, there have been only two problems.
>
> 1. Brake pedal pulsation
>
> 1a. This was corrected by taking a light cut off the rotors. There is,
> however, a noticable "shudder" (Hyundai's word for it is "judder") when
> applying the brakes at 70mph and slowing down to, lets say, 60mph.
> No pedal pulsation. More of a chassis pulsation cause by one of the
> rotors having large hot spots.
>
>
> 2. Steering wheel shimmy between 65 - 80mph.
>
> 2a. Had the original Michelin MXV4's road force balanced and match
> balanced on a GSP 9700. Got it to inprove some, but not enought to
> satisfy me. Three of the four steel wheels had lateral run-out greater
> than .040". Replaced the wheels with MB 177-5703C Chrome wheels. All
> four of the new wheels had -0- lateral run-out and at most .002" radial
> run-out. They balanced out like a dream. There was some RFV which we
> reduced by repositioning the tires for the front. The existing
> Michelins where put back on the new wheels in radom order (i.e. not in
> the same position they came off of. Test drive gave me extreem
> steering wheel shimmy. So, OK the tire are toast and I have a really
> nice set of chrome wheels. Replaced the tires with a set of Michelin
> Destiny's. These are really nice tires sold by Discount Tire Company.
>
> After replacing the tires 90% of the shimmy is gone. For some average
> drivers this may not be a problem for them.
>
> While the my car was on the lift I had the technician run it up to 80mph
> without the tires and wheels on. We could feel the remaining vibration
> start at 65mph and fade away at 80. Perhaps the frequency was just to
> high to make it noticable at that speed. The vibration was strong
> enough that I could feel it in my arm that was resting on the roof of
> the car as well as on the lift it self.
>
> Now the question is what components and in what sequence do we start
> eliminating front end items. I think i would start with measuring the
> rotor run-out on both rotors first. After viewing the TSB and service
> info at Hyundai's Tech Web, there are other possibilities such as
> scratched wheel bearings, CV joints, dynamic damper in the drive shafts.
> (not sure if my version has these or not. Good news is the service
> manager at the Hyundai dealer has agreed to work with me to try to
> locate the problem.
>
> Has anyone had a similar experience and found a solution?
>
> Thanks you.
>
> Paul
> theBun
> remove NOSPAM from my return address if replying to my email address
>