misaligned wheels and vibration at certain speeds
Xiao-He Zhang
My questions are:
If the front wheels are misaligned, willl the car vibrate violently at
certain speed? Does a slight mismatching in size of front tires has anything
to do with it? Does the misalignment or mismatching in size of rear wheels
cause the vibration at certain speed?
The car in question is a 1984 Colt. About two weeks ago, I discovered that
a strip of the front right tire, about 10 inch in length and in the outer edge,
has been worn down to steel. So I had it changed. Since the car also tended
to drift to the right, I also did a front wheel alignment.
The alignment was not done satisfactory but the mechanics told me that it's
because of the mismatching in size. The car drifted to the left after he
switched the front wheels. Now after driving the car at 55 MPH, another
trouble with the car, which it never had before, appeares. It vibrates
violently when driven between 50 and 55 MPH, but not so when above 55 or below
50. The vibration exists even when the car is in neutral gear. I suspect the
alignment is not done properly. The garage will not warantee their job. I've
moved the replaced tire to the back but the car is still shaky. Before I take
this car to another garage, I would like to hear what you people have to say.
Any comments, suggestions are very appreciated.
Thank you very much in advance!
X. Zhang
Roy Smith
> [The car] vibrates violently when driven between 50 and 55 MPH, but not
> so when above 55 or below 50.
Almost certainly, the problem is not misalignment, but that the
front wheels need rebalancing. Having a farily narrow resonant zone in
which the car shakes violently is very diagnostic for this. Happend to me.
Should be cheap to fix ($10/wheel?)
> The garage will not warantee their job.
Find a new garage.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
r...@alanine.phri.nyu.edu -OR- {att,cmcl2,rutgers,hombre}!phri!roy
"Arcane? Did you say arcane? It wouldn't be Unix if it wasn't arcane!"
SYG
>certain speed?
Yes, it might. Other causes may be:
0) Tire inflation. Buy a tire air guage and check it.
DO NOT (do not, do not) EVER rely on the pressure on the
air pump...even the automatic shut off ones.
1) unbalanced wheels (when you get new tires, you MUST have them dynamically
balanced (they are spun on a machine which detects wobble; the machine
tells the mechanic where to put weights to correct for the wobble;
the tire is then spun again to check if the weights were put on correctly).
Do not get static balancing (which may be offered at a cheaper price).
Balancing can cost as much as $10/tire.. and it is necessary.
The best balancing is done while the tire is on the car, but that
service is rare and more expensive.
2) tire size or type different on a single axle. Tires come in pairs:
front and rear. For best performance and safety, a pair should be of
the same type (ie: same brand, same type, same name, eg: Goodyear
Radial Tiempo 155/75R 14 .(snide comment: ugh)) and similar tread thickness (ie:
a new tire on one side and a tire that has gone more than 10,000 miles
on the other is not good). If you think about it, it makes sense:
going straight, tires in a pair should turn the same number of times.
If one tire is a little smaller that the other, the car will not want
to go straight, to keep it straight, the smaller tire will drag
a bit and a some speeds may hit a resonance and vibrate a great deal.
3) front end or rear end problems, such as loose or worn suspension,
bearings, etc. The alignment should have spotted this and perhaps 4)
4) The car was once in an accident, and the frame is crooked. (Colt
is very easy to get bent frame)
#3) and #4) should be apparent in an alignment, assuming that
the people doing the alignment knew what they were doing.
>a strip of the front right tire, about 10 inch in length and in the outer edge,
>
> The alignment was not done satisfactory but the mechanics told me that it's
>because of the mismatching in size. The car drifted to the left after he
>alignment is not done properly. The garage will not warantee their job. I've
If the tires are not the same, the alignment cannot be done properly.
See my warnings above about tire pairs. If the other tire is worn or
of a different type, you should have replaced both and keep the
"good" tire as an extra spare. Your new tire might not have been balanced
(check for little gray or silver weights along the rim of the wheel...
if there are none, it wasnt balanced)
These things cost $$, but it saves $$ in the long run.
If you are only keeping the car for another year, just
make sure that the tire is balanced. If you are keeping it
any longer, get another tire of the same type for the other side.
>moved the replaced tire to the back but the car is still shaky. Before I take
>this car to another garage, I would like to hear what you people have to say.
>Any comments, suggestions are very appreciated.
If you are getting anything done for the car, ask what they charge to
inspect the front end/rear end. Many places will look for free (especially
if you are buying something else from them). If they find something
wrong, they should show you what is wrong.
Richard W West
>
> If the front wheels are misaligned, will the car vibrate violently at
>certain speed? Does the misalignment or mismatching in size of rear wheels
>cause the vibration at certain speed?
>
two weeks ago. I have called back, and they will inspect/repair it tomorrow.
There are a number of different things that could cause the car to vibrate
violently at a certain range in speed (50-55MPH is where it is the worst).
The first is that it could be that the front tires are simply out of balance.
This would cause a very slight wobble that would increase as you increase your
speed. Another possibility could be that the alignment just was not good. This
would cause the car to <of course> drift slightly in one direction or another
and a violent front end shake will occur (making the steering wheel shift
along with it). Your shock(s) or strut(s) could be bad, but the symptom for
that would be a tremmor originating from the specific shock/strut, not a voilent
vibration.
The more expensive possibilities couble be that the ball-joints of one of the
front wheels is wearing down/going bad or one of the tie rods is going bad.
Either of these two can be mistaken as one of the more simpler/less expensive
possibilities, but can be very dangerous or even fatal in the consequences.
Fortunately, if you brought your car to a garage that you trust, they would
have caught either of these problems while doing the alignment.
> The alignment was not done satisfactory buy the mechanice told me that it's
>because of the mismatching in size. The car drifted to the left after he
>switched the front wheels.
Yes, the car is definitely out of alignment. You figure that all roads are
sloped to the right so that rain can run off to the sewers, so if anything,
all cars should drift slightly to the right. Drifting to the left shows
poor alignment since the car is actually drifting up (not down) a slight incline
, and the very slight difference in tire size (assuming that the new tire put
on has the same dimensions as the old one) would have little or no effect on
the alignment. Only if you put a different sized tire on there would any
real difference occur (i.e. putting a P195/55 R14 where there once was a
P185/55 R14 or something like that).
>I suspect the alignment is not done properly. The garage will not warantee
>their job.
Whoever already said this, they were absolutely correct. Go to a different
garage. If they do not guarantee their work, then their work is not worth the
money your are putting towards it.
>moved the replaced tire to the back but the car is still shaky. Before I take
>
> Thank you very much in advance!
>
No, problem.
>X. Zhang
-Rich West
Disclaimers? What for? Ohhh..
These ideas are mine! And anyone can have them!
Chris Schanzle
>In article <9005082347...@Romeo.Caltech.Edu> xia...@CitRomeo.BITNET (Xiao-He Zhang) writes:
>>
>> If the front wheels are misaligned, will the car vibrate violently at
>>certain speed? Does the misalignment or mismatching in size of rear wheels
>>cause the vibration at certain speed?
>>
>>because of the mismatching in size. The car drifted to the left after he
>>switched the front wheels.
>Yes, the car is definitely out of alignment. You figure that all roads are
>sloped to the right so that rain can run off to the sewers, so if anything,
>all cars should drift slightly to the right. Drifting to the left shows
>poor alignment since the car is actually drifting up (not down) a slight incline
>, and the very slight difference in tire size (assuming that the new tire put
>on has the same dimensions as the old one) would have little or no effect on
>the alignment.
[I don't like this assumption about road angles/slopes; Xiao-He may,
like myself, be able to detect over a period of different roads
whether or not a car is generally driving straight or not. Yes, you
need to LOOK at the road to see if it's flat or sloped for runoff.
Additionally, a car generally is more difficult to turn in one
direction if it is pulling to the other side; though more difficult to
tell with power steering.]
Time out! I'm not sure what happens when you mismatch tire sizes
(i.e., I've never done it myself), but what CAN happen is that the
alignment was not perfect for the last XX thousand miles, causing the
tires to wear unevenly (more or less on the inside of the tread, as
opposed to other wear problems). Now, if you go and get yourself an
alignment, yes - now the suspension is straight, but the tires are not
sitting flat on the ground anymore (but they used to!).
This phenomena is especially noticable if the tires haven't been
rotated in the last 10-20K miles, THEN you rotate them. You may
quickly realize that your suspension is not quite up to snuff. Again,
no PROPER alignment will make the car drive straight on these tires.
You must decide whether it's worth tossing tires that may have tred,
but are uneven.
>>I suspect the alignment is not done properly. The garage will not warantee
>>their job.
>>moved the replaced tire to the back but the car is still shaky.
Did it shake exactly the same way? Did the steering wheel shake
exactly the same way? If not, I would strongly suspect a rebalance is
in order. If so, try some of the other posted suggestions.
One final suggestion: if you drive on rough and tough roads, you may
want to invest in Sears' Lifetime front-end alignment: $50-$60 for the
first alignment, FREE for all others separated $5K miles (or so) apart.
In any case, find a good garage. Don't be afraid to try others!!
______________
"I must go. Somewhere a bug is happening." Chris Schanzle, Comp. Scntst
NIST ch...@sunset.ncsl.nist.gov
Bill Ingram
%front and rear. For best performance and safety, a pair should be of
%the same type (ie: same brand, same type, same name, eg: Goodyear
%Radial Tiempo 155/75R 14 .(snide comment: ugh)) and similar tread thickness (ie:^^^^^^^^^^^^^^^^^^^^^^^^
Is there such a size????? Even my bug has 165/75 x 15. I know that cross-sec-
tion is available in 13 inch diameter, but 14?
Bill @ sequent
Michael McDaniel
How many miles are on the old tires?
My wife's car had 2 tires where the steel belts seperated (at 40K+)
(Before anyone starts, they were never rotated regularly, swapped
indescriminatly, and occasionally significantly under inflated .....)
As the belts separated, the vibrations got worse at particular
speeds but was nonexistent at others. Take a close look at the
older tires (side to side and all around).
This sounds like a long shot, but can be a potentially dangerous
situation.
Mike
Teck-Joo Chua
>>In article <9005082347...@Romeo.Caltech.Edu> xia...@CitRomeo.BITNET (Xiao-He Zhang) writes:
>>>
>>> If the front wheels are misaligned, will the car vibrate violently at
>>>certain speed? Does the misalignment or mismatching in size of rear wheels
>>>cause the vibration at certain speed?
I have a vibration problem with my car too. It is a 83 Toyota Supra
(rear-wheel drive). If I cruise at speeds of 40 MPH and above and I increase
pressure on the accelerator very slightly, a rather loud vibration will come
from the rear (sounds like from the axle or something). This will go on
unless I either let up on the accelerator or step on it harder. The speeds at
which this can happens varies but is always at 40 MPH or above.
I recently had all my tires changed (<1500 miles) and also had a front-end
alignment done. Could a rear mis-alignment cause this problem? My steering
wheel does not vibrate (though it does once the vibration behind gets so
strong that the whole car vibrates), so I don't think it is due to unbalanced
wheels.
Any advice would be much appreciated. Thanks.
--
-------------------------------------------------------------------------
* Teck-Joo Chua | Computer Science Department *
* Email: ch...@cs.stanford.edu | Stanford University *
* Phone: (415) 322-3070 | Stanford, California 94305 *
Chris Schanzle
>>
>> If the front wheels are misaligned, will the car vibrate violently at
>>certain speed? Does the misalignment or mismatching in size of rear wheels
>>cause the vibration at certain speed?
>>
>>because of the mismatching in size. The car drifted to the left after he
>>switched the front wheels.
>Yes, the car is definitely out of alignment. You figure that all roads are
>sloped to the right so that rain can run off to the sewers, so if anything,
>all cars should drift slightly to the right. Drifting to the left shows
>poor alignment since the car is actually drifting up (not down) a slight incline
>, and the very slight difference in tire size (assuming that the new tire put
>on has the same dimensions as the old one) would have little or no effect on
>the alignment.
[I don't like this assumption about road angles/slopes; Xiao-He may,
like myself, be able to detect over a period of different roads
whether or not a car is generally driving straight or not. Yes, you
need to LOOK at the road to see if it's flat or sloped for runoff.
Additionally, a car generally is more difficult to turn in one
direction if it is pulling to the other side; though more difficult to
tell with power steering.]
Time out! I'm not sure what happens when you mismatch tire sizes
(i.e., I've never done it myself), but what CAN happen is that the
alignment was not perfect for the last XX thousand miles, causing the
tires to wear unevenly (more or less on the inside of the tread, as
opposed to other wear problems). Now, if you go and get yourself an
alignment, yes - now the suspension is straight, but the tires are not
sitting flat on the ground anymore (but they used to!).
This phenomena is especially noticable if the tires haven't been
rotated in the last 10-20K miles, THEN you rotate them. You may
quickly realize that your suspension is not quite up to snuff. Again,
no PROPER alignment will make the car drive straight on these tires.
You must decide whether it's worth tossing tires that may have tred,
but are uneven.
>>I suspect the alignment is not done properly. The garage will not warantee
>>their job.
>>moved the replaced tire to the back but the car is still shaky.
Did it shake exactly the same way? Did the steering wheel shake
Peter Sheriff
Front wheel drive cars are very susceptible to wheel vibration
caused by overtightening the wheel nuts. If you have vibration and
it only started after the wheels were removed and replaced, it may
be a good idea to torque the wheel nuts to spec. Some of those service
station air wrenches can put a lot of torque on a nut.
Pete
Ross A. Jeynes
>One final suggestion: if you drive on rough and tough roads, you may
>want to invest in Sears' Lifetime front-end alignment: $50-$60 for the
>first alignment, FREE for all others separated $5K miles (or so) apart.
I got the lifetime alignment for my '81 Rabbit, and I've used it several
times. Most of the time, they don't even ask to see the original agreeement,
if you're getting other work done as well.
Unfortunately, they don't do all cars! I bought a TR-7 last week, took it
in to get the lifetime alignment, and was told that "we don't align
Triumphs."
WHY NOT? Isn't the alignment process pretty much the same on all cars?
There's nothing particulary scary looking about the steering mechanism on
the car; in fact it looks simpler than my Rabbit's. (This is due in part
to the fact that the Rabbit is Front Wheel Drive, the Triumph is Rear.)
Why won't they align my car, and where can I go for a similar lifetime
alignment?
-ross jey...@adobe.com
Dave Post
One of our cars recently came back from a shop ( AAMCO yearly inspection ) with a violent vibration at 35-60 mph. It was totaly coincident. The front
U-joint had failed. The clue was the frequency of vibration seemed too high
for the tire's speed and that the intensity varied with acceleration.
I checked it with the transmission in park and jacking one rear wheel off the
ground and rotating it backwards and forwards while watching the "relative
motion" at the U-joints.
I mention this because no one else has, yet.
David Post po...@hpfcla.hp.com hplabs!hpfcla!post