Vibration at 65-70 mph

[Jimmy9190]

This is for the 2001 Dodge Dakota in my signature. It is just a basic 2 wheel drive Extended Cab truck. I am trying to figure out where I am getting a vibration and shake in my steering wheel. It only happens between 65 to 70 mph but it is a fairly bad vibration. I believe I have warped front rotors, because of a shake/shimmy when I am slowing down to stop. It's not real bad, but it is present when I am coming to a stop from about 20 MPH on down to 5 or less. I have not replaced or turned my rotors yet.

I noticed this vibration problem this past Thursday on the interstate. I don't get out on the interstate much so I don't get much chance to drive over about 50 or 60 MPH. My truck does fine at the slower speeds, no vibration is present. I had the wheels balanced today and the vibration is not as bad as it was on Thursday but it is still there. So my question is, can rotors that may not be running exactly true cause a steering vibration at highway speeds as well as when you are slowing down to stop? The shop that did the balancing is a really good local independent garage. I have no doubts about their work, they are the best around here. They also rotated my tires in a standard front to back, back to front on the same side pattern. I rotate the tires myself on a cross pattern. My tires are not quite 2 years old, BFG Long Trail Tours, 235/75R15 with about 18,000 miles on them. I keep them at 37 psi. The wear patterns all look good, there is nothing on the tires to indicate any suspension problems.

I am scratching my head. My ball joints, tie rods, wheel bearing/hubs and just about all of my front suspension and steering parts are either new or fairly new within the last couple of years and they all check out OK. I have no play or abnormal motion from the wheels at all. I may try rotating the tires in a cross pattern and see if that helps. Thanks for any help on this.

 

[tomcat27]

rotors could cause the problem. could be tires also. has your truck ever been parked for a long time? I've apparently ruined a few sets of tires by parking them for months/years. recently I had a set of new tires installed 2 years ago. and parked the car for 18 months. coming out of storage, with only 5k miles on the tires - really bad vibration at speed. I jacked up a couple corners of the car just enuf to get the tires 1/4" off the ground. then I watched the clearance change as I spun the tire. bent rims will also cause mystery vibrations.

 

[Boomer]

Had a friend who had a similar problem. Turned out one of the weights on his driveshaft on his truck fell off and the driveshaft was slightly unbalanced. Caused steering wheel vibration, etc. Drove him nuts until he crawled underneath and saw a freash rectangular metal area on the driveshaft. Had it rebalanced and the problem disappeared.

 

[JimPghPA]

Cross rotation can be a very bad idea unless you take the tires off of the rim and flip them and remount so that they are rotating in the same direction they were before rotating them.

The force exerted on tires during breaking is much more than the force during accelerating. And the belts become aligned to handle the huge force of breaking.

When you cross rotate without removing from the rim and flipping and remounting, then the belts will move within the rubber and this can cause uneven bulges within the tire. If this has happened there is no way to fix those tires.

Because people do not want the time and cost hassle of removing the tires from the rims, flipping them, remounting them, and re-balancing them most people just keep them on the same side.

Years ago cross rotation use to be recommended, but seldom did people maintain the same rotational direction and because of that many tires were damaged by shifting belts.

And in the distant past I had tires damaged by cross rotating. You could see the bulge in the tire from a damaged belt when this happened.

For many years now I same side rotate the tires on both of our vehicles, but never cross rotate, and using same side rotation I have never had a tire develop the classic bulge of a shifted or broken belt.

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Re: Boomers post about the drive shaft. Up here in the northern states almost all Dakotas are 4WD (probably because of winter). I did know that Dakotas are made with only 2WD, but I thought those were front wheel drive. Is you 2WD Dakota front wheel drive or rear wheel drive? Front wheel drive in general do not have a balance weight.

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There are many post on google about the front wheel drive bearings going bad on Dakota trucks.

There are YouTube videos showing how to use a mechanics stethoscope with the vehicle up on a rack and someone in the vehicle to run the tires at highway speed so someone else under the vehicle could use the mechanics stethoscope to locate the noisy worn out part(s).

 

[HM12460]

Jimmy, how many miles? Might want to check the u-joints on your drive shaft also.

 

[Jimmy9190]

Thanks for the replies. I had no idea about the cross rotation. An old timer told me long ago that was the best way to rotate tires, he said it helped eliminate any pulling to one side or the other.

I will sure enough take your advice here and rotate on the same side from now on. I have only done the cross rotation once or twice anyway, so I hope there is no tire damage. I have had all 4 tires off the truck recently and not seen any bulges or indications of bad tires. The guys at the shop today found no tire problems either.

Truck is just a basic 2 wheel drive extended cab with 152,200 miles on it. V6 and a 5 speed manual. AFAIK there are no balance weights on the drive shaft. I have never seen any weights on it.

The rotors need to be replaced anyway, and new rotors are only a few bucks more per side than resurfacing. I will replace the rotors next and see if it helps. I do appreciate the help here.

 

[MinamiKotaro]

In my experience, cross rotating is what prevents bulges and, especially, flat spots.

 

[Merkava_4]

This really, really sounds like a tire balance issue.

 

[yonyon]

On a 2WD Dakota you don't have so many parts that could cause this problem as with a 4WD. You've got your tires, rims, rotors, and bearings. If it were the bearings, they'd have to be so bad you get nasty brake noises.

If it's the rotors, it's a balance problem, which really you can only get if they're balanced with weights jammed into the cooling vanes (one fell out) instead of balanced by grinding or drilling. By the time you find someone who's equipped to check and correct the balance of a rotor you would be better off to get a new pair.

Before you worry about the rotors, you need to eliminate the most likely culprit: tire/wheel assemblies. Swap the fronts with the rears. If this makes any change you know that tire/wheel assemblies are at least part of the problem. Going beyond that, you need to be sure they're balanced properly.

Alloy wheels are can fall victim to corrosion. If the center hole (on the inboard side) is not a nice smooth round machined hole it may not center properly on a balancer and the result of that is that the tire will be balanced incorrectly. You also need to verify that the person operating the machine is using a centering cone that fits this hole neatly on the sides of this cone. Smaller shops may not have a good selection of cones and the operator may use an incorrect cone because "this one fits best" even though it doesn't fit. While balancing, be sure that the operator of the machine is watching for any runout in the rim. Any runout in the rim that is visible to the eye is too much and should be corrected. If the balancer is a Hunter machine with SmartWeight feature, this should be turned off. If all this checks out and the tire/wheel assembly is balanced properly, a Hunter balancer with Road Force measurement should be used to check for any structural defect in the tires. If that checks out as good also, then it's time for new rotors.

 

[Jimmy9190]

Thanks again. Tomorrow I will decrease my air pressure to 35 psi and rotate the tires in my cross pattern as I would have done if the shop had not done it today in the same side pattern. I want to see if the vibration is still present after moving the front tires to the rear. If it is present well maybe I have tire problems. I wonder if maybe the tire store where I got the BFG's will do any type of free balancing diagnostics and if they find a bad tire or tires maybe they will pro-rate some replacements. There are a lot of bad reviews on tirerack.com on the Long Trail T/A Tour, especially after they get about 20K on them. There are good reviews too but some folks reported they could not get the tire to balance correctly even after multiple attempts. I realize the problem could be I have a bent rim too, but I have not hit or run over/into anything on the road, so how that may have happened is anyone's guess.

 

[Jimmy9190]

I just checked the receipt for my tires. They only have less than 11,000 miles on them. I do not go off road, and I do no towing or heavy hauling. I can't believe the tires are bad at only 11K. I will try the rotation first. I have read about rotors having rust build up inside the vanes. I may need new rotors anyway so that may be the next thing on the list of possible causes.

 

[Turk]

Somewhat in order...

Rotate tires.

Road Force balance.

Rotors.

CV axle.

Driveshaft.

Let us know!

 

[CapriRacer]

Amateurs! Sheesh!

First, the myth about cross rotation: Back before radial tires were commonplace - let's say the 1960's - cross rotation was the norm. When radial tires were introduced, there were lots of issues with tire failures - and one of the suggestions was not to cross rotate - that is, only rotate on the same side. The idea was to prevent the separations that were forming on the one side of the steel wire, from being encouraged to form on the other side, completely encircling the wire. This didn't have a lot of success in preventing failures.

- BECAUSE - the real problem was the adhesion of the wire to the rubber. It turned out that one of the chemicals used to promote bonding to the steel caused, under certain circumstances, an acid to be formed which corroded the steel. Lots of research was done to remove water from the manufacturing process - all to no avail. Once the chemical was removed, the problems disappeared (OK, let's say, THAT problem disappeared!)

It took a while for each tire manufacturer to figure this out - and Firestone was one of the last ones. The result was the infamous Firestone 500 recall.

But those days are way behind us and the issue of cross rotation isn't one.

Don't get me wrong. There is nothing inherently wrong with rotating on the same side, it's just that cross rotation is ever so slightly better.

 

[CapriRacer]

- And now about the original post:

Warped rotors? If the vibration only appears when the brakes are used - and ceases when the brakes are released - it's the rotors. And warped rotars can cause a vibration to be present even when the brakes aren't being used.

Tires? Wheel end vibrations (meaning tires, wheels and anything else rotating) tend to show up in the 50 to 70 mph range - and usually not at other speeds - and are there every time that critical speed is reached. Wheel end vibrations can be out of balance, but it could also be out of round.

Tires will develop an out of round wear condition due to mis-alignment. Because of this, once tires get beyond a year, tire manufacturers will NOT warrant vibrations (there's also a wear limitation!)

I think the first step in this is to rotate the tires. If the vibration changes - particularly if it moves from the steering wheel to the seat - then it's a tire and wheel issue.

If it doesn't move, then it is something else.

 

[Jimmy9190]

Thanks again for the replies and help. I thought about this last night. The shop rotated my tires yesterday. They moved the rears to the front and fronts to the rear, each on the same side of the truck. When I cross rotate I move the rears to the front on the same side and I move the left front to right rear and right front to left rear. This is the method that is recommended by Dodge in my owner's manual. So the shop has already moved the rears to the front. The vibration was present on Thursday before I had the rotation and balance done yesterday. So it makes no sense to re-rotate today because the shop did the same thing yesterday as I would do today if I re-rotated the tires myself. The vibration will be present regardless of rotation.

I am headed out now to pull the front wheels and see what I can see on the rotors. I have a cheap caliper but it may not tell me very much. I have also taken a slight hit on MPG in the last month or two. I have no idea about it but I wonder if a warped rotor could cause a highway speed vibration, then could a warped rotor also contribute to a half mile loss of MPG?

I am also going to check the u-joints. I don't have any clunking when I put the truck in gear or hesitation/noise when I accelerate, but I want to be sure and rule out a bad u-joint. They can cause vibrations at highway speeds as well.

Thanks for everyone's help on this.

 

[Jimmy9190]

I believe I have located the problem. It looks like the front u-joint is bad. I will post another thread and add pics to see what you guys think about it. I don't know much about u-joints.

 

[eljefino]

Can you drop the front driveshaft without dumping the transfer case's oil all over? That would be a pretty instant diagnosis IMO.

 

[Jimmy9190]

There is no front drive shaft. The truck is only a 2 wheel drive basic truck with 6 cylinder and a 5 speed manual. The "front" u-joint I was referring to is the u-joint on the driveshaft at the transnission tail piece. The driveshaft has 3 u-joints in it, one at the trans, one in the middle and one at the differential. I called the suspected leaky u-joint the front one because it is on the front end of the drive shaft at the trans.

 

[yonyon]

Assuming you're about to change u-joints for the first time, here's my advice:

Buy four of them. Once you get it down, they're (usually) not a big deal, but this is your first time. There's a very good chance that at some point you'll be standing there wondering where all those little needle bearing rollers went and whether or not it's okay to live with just one of them being missing. If you have an extra joint, you're cool. If all goes smoothly and you don't need it you still have the receipt so that's not a problem either.