vibration cure question
#21
Le Mans Master
Thread Starter
When it's happening, you can see the hood shaking - most noticeable directly over the front wheels. It does seem to be worse on rougher road surfaces, but I'll have to check that more carefully this week to be sure.
#22
Race Director
I have new front shocks too. Rebalancing the fronts removed about 80% of the vibration but some is still there. You could try pumping your tires up to max pressure + 2-3psi. Getting more of the tire off the ground might help you isolate whether the tires are an issue (even after balancing). Anything short of new tires probably won't prove diddly-squat.
#24
Burning Brakes
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At the last shop I worked at,I balanced my tires on my vette with our "regular" balancer & still had a vibration/shaking at highway speeds.I brought it to a shop that had a road force balancer & that made all the difference.Did the shop check for a wobble or hoping while the tire was being balanced?Could be a defective tire.Did this problem occur after any work was done or parts were replaced?Did you throughly check your suspension?I am working on a car tommorrow that shakes while driving due to bad/worn out inner tie rods
#25
Race Director
I guess they never drive above 70 or go to the track.
#26
Team Owner
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St. Jude '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21-'22-'23-'24
What I found out was the u-joints will "checkout" just fine until removed and inspected. If you look closely around the grease seal you may find the slightest signs of "rust" coming from under the seal.
This is indicative of a failed/ceased needle bearing pack. It will produce a small yet annoying vibration.
The batwing rubbers are seldom the cause unless completely disintegrated.
#27
Le Mans Master
Road force balancing:
Measures vibrations by placing a tensioned spinning meausrement wheel in contact with the tire. It can detect vibrations caused by run out (out-of-round) conditions, as well as normal weight distribution problems. Takes the guess work equation away from a tire technician. Do a google search for a list of local shops that use these types of machines.
Road Force Video:
Measures vibrations by placing a tensioned spinning meausrement wheel in contact with the tire. It can detect vibrations caused by run out (out-of-round) conditions, as well as normal weight distribution problems. Takes the guess work equation away from a tire technician. Do a google search for a list of local shops that use these types of machines.
Road Force Video:
#30
Burning Brakes
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Who has those? Cost? Sounds like a good option. With mine, it just seems like I'd need a balancer that spins faster/higher. NTB (where I go) says they get the occasional person wanting the same thing. They couldn't understand why.
I guess they never drive above 70 or go to the track.
I guess they never drive above 70 or go to the track.
spots on the rim & tire to balance/cancel each other out.It took a few tries but what a differenceI believe it cost $160 total($40 a tire) but was definately worth it.That machine will also tell you if the tire is bad,rim is bent,etc,etc.Check it out & I recommend it if you drive your car at high speed like.....
#31
Melting Slicks
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Check horizontal & vertical movement @ the drive shaft yoke. The tailshaft bushing may be worn allowing the front u joint to rotate in an eliptical orbit. This vibration can normally be felt in the floor pans, seat etc. Severe cases cause body shudder.
Intermittent vibrations are normally caused by a tire(s) & can be heat related.
IMHO: The belts are probably moving around in the tires.
As suggested, road force balancing IS BEST & may identify a problematic tire.
Before spending $$ on balancing insure that the wheels are straight & true.
The following check is time consuming & tedious however it may save some tail chasing & identify the problem area.
Using a a dial indicator check each wheel for lateral & radial run out. Check the outside & inside of each wheel @ the wheel lips. IE: The horizontal & vertical flats next to the rolled edge. Before indicating, remove the wheel & clean any corrosion from the face of the hub & the wheel mounting surface.
To index a wheel: Mark the wheel & one corresponding wheel stud, indicate the wheel & record the readings. Move the wheel one set of bolt holes & indicate it again. Continue around the bolt circle. Install the wheel at the position on the hub that had the lowest amount of run out. Mark the wheel & stud & always reinstall the wheel in that location.
IIRC, the 89 shop manual allows .040 run out in either direction, lateral & radial.
Luck with your hunt.
BTW, enjoy reading your posts mcm95403, you have brought some enthusiasm to the forum.
Intermittent vibrations are normally caused by a tire(s) & can be heat related.
IMHO: The belts are probably moving around in the tires.
As suggested, road force balancing IS BEST & may identify a problematic tire.
Before spending $$ on balancing insure that the wheels are straight & true.
The following check is time consuming & tedious however it may save some tail chasing & identify the problem area.
Using a a dial indicator check each wheel for lateral & radial run out. Check the outside & inside of each wheel @ the wheel lips. IE: The horizontal & vertical flats next to the rolled edge. Before indicating, remove the wheel & clean any corrosion from the face of the hub & the wheel mounting surface.
To index a wheel: Mark the wheel & one corresponding wheel stud, indicate the wheel & record the readings. Move the wheel one set of bolt holes & indicate it again. Continue around the bolt circle. Install the wheel at the position on the hub that had the lowest amount of run out. Mark the wheel & stud & always reinstall the wheel in that location.
IIRC, the 89 shop manual allows .040 run out in either direction, lateral & radial.
Luck with your hunt.
BTW, enjoy reading your posts mcm95403, you have brought some enthusiasm to the forum.