My "99" Ram 1500, QC, 4X4 has noticeable vibrations that come on around 62 to 65 mph and less noticeable at around 40 mph. I took it in and had the tires re-balanced and it got better but is still there. The Les Schwab guys said that some of my tires were about 2.5 ounces off and they got them to about a half an ounce. Also, the vibrations I feel at 40 mph are very pronounced when I am decelerating. For example, if I'm doing 60 mph and I start to slow down, I don't notice the vibes until I get to about 40 mph and then it goes away below 40. I don't feel the vibration in the brake pedal at all, so I really don't think it is a warped rotor. Could I have a tire that is out of round or something else going on with the truck?
52 M37
12-04-2002, 08:21 AM
Do you feel the vibration in the seat of your pants or the steering wheel? Seat of your pants is mainly in the drivetrain (possibly rear tires) steeering wheel is in the front end (possibly front tires)
Were the tires spin balanced? Balanced on the truck?
Tires can have belts inside go bad and cause vibrations. The person who rebalanced your tires should have noticed if the tire was doing alot of jumping around like a twisted or broken belt would cause.
How many miles on the truck? Tires?
Are the tires oversized or stock?
Have you had any hard hits to the front tires like a curb?
I remember seeing a TSB about 4x4's and support arms after a hit to the tire. Anyone know if this TSB mentioned vibration? I wish I could recall which one it was. I will try to find it.
Hope some of this helps.
Rich
Rusty
12-04-2002, 08:46 AM
CES21,
I had a similar problem with my '02, ended up being an out of round wheel. Mine was replaced under warranty. Maybe you could go back to the place that did the balancing and have them check the wheels too.
Rusty
CES21
12-04-2002, 06:36 PM
Thanks for the replies. I feel the vibrations in the seat of the pants. No vibes in the steering wheel. I have just over 35,000 miles on the truck and about 31,000 miles on the tires. The tire size is LT265/75/16 mounted on stock Dodge alloys. I believe the tires were spin balanced the last time. So far I haven't hit any curbs very hard at all. I have a feeling it's coming from the rear of the truck. I was thinking, maybe the vibrations at 40 mph are more noticeable when decelerating because more of the truck's weight is transferred from the back to the front. Less weight on the back end may make the out of roundness of one of the tires more noticeable? It is deffinitely more noticeable under harder braking. Just a guess. Any more help would be appreciated.
MDRAM
12-04-2002, 07:44 PM
Everything has what is called a "resonant frequency". This is the frequency at which a particular part's natural vibration will amplify considerably. For example if your tires are out of balance , the vibration will increase exponentialy with the increase in rpm of the wheel; the faster you go, the worse it vibrates. On the other hand front end components have their own resonant frequency which seems to be above normal driving speeds. When the front end wears (ball joints and tie rod ends) this frequency lowers due to the front end getting looser. This condition causes the classic "it vibrates between 65-70 but goes away when I go faster or slower". This can also happen when the combined resonant frequency of a worn shock and a out of balance or out of round tire occurs. I would also not rule out driveshaft u-joint problems. This would be evident by the high frequency vibration that occurs due to the drive shaft turning 3.5 to 4 times the wheel speed.
My '95 1500 4wd had a front end vibration that I described at 45k miles and the cure was to replace the drag link and tie rod ends. Vibration was between 65 and 75 mph only.Tighten the front end and problem solved.( I had to prove it to the dealer, and the problem is back at 75k miles)
Sorry to be lengthy and not to bore you, but it seems alot of mechanics don't understand vibration theory and how it relates to the automobile. (I said alot but not ALL guys!!)
:cheers:
52 M37
12-05-2002, 10:23 AM
Have you rotated the tires to see if the vibration moves with the tires?
Rich
WARLOCK
12-09-2002, 12:13 AM
driveshaft??
Blown5.9L
01-05-2003, 12:00 AM
how about axle bearing going south, with a pickup it's sometimes hard to hear noises up in the cab... but if not i'd go with a bad tire, do you have a same size spare you can rotate around to rule out a tire at a time, borrow a buddies spare and replace both rear tires... you can borrow mine... and lastly what type tire is on your truck?
