Bad 55+mph vibration

[BlueNostromo]

Hey guys, I was getting sick of Facebook. Anyway, I just put some new 32s on new 15x8 inch rims. I'm getting awful vibration now. These wheels have been rebalanced twice and they haven't said anything about a bent rim. I hope they would have noticed.

I've also replaced my upper ball joints. While doing that, I inspected my tie rods and they seemed fine. U-joints didn't look off, but I need to look a little harder before I'm sure.

Any ideas?

 

[Dirtman]

Inspect the driveshaft carefully. Driveshafts are balanced with weights welded on and the weights sometimes fall off over time. Same with brake drums, if a weight falls off the rear drum you'll get a vibration. Look for "witness marks" where it looks like something was welded on and now there's just a clean spot.

If the vibration started when you got the tires though I would suspect a bad balance job and take it to a different store.

 

[Uncle Gump]

Are they new tires?

Have you tried to move the vibration by rotating the tires? this can help you determine the suspect tire.

I would also look at the wheel weights. If you have one or a couple that requires a couple three ounces of weight... try breaking the tire down and rotating the tire 180 degrees. Tires have a heavy spot as do the wheels. When the heavy spots line up it takes a lot of weight in one area to balance and even though it says it's balanced... you have a out of balance condition. When I bought my truck it vibrated at highway speed. I had them check them they said they were fine. When I got to looking one had nearly 3 ounces in one spot. Repositioned the tire on the wheel... and all was good.

 

[franklin2]

The tires can be out of round. No amount of balancing will cure that.

 

[BlueNostromo]

The tires can be out of round. No amount of balancing will cure that.

I wanted to get these tires/wheels RoadForce balanced to be sure it isn't that. Especially since both the tires and wheels are new. I definitely wasn't having issues this bad until the whole new set.

Are they new tires?

Have you tried to move the vibration by rotating the tires? this can help you determine the suspect tire.

I would also look at the wheel weights. If you have one or a couple that requires a couple three ounces of weight... try breaking the tire down and rotating the tire 180 degrees. Tires have a heavy spot as do the wheels. When the heavy spots line up it takes a lot of weight in one area to balance and even though it says it's balanced... you have a out of balance condition. When I bought my truck it vibrated at highway speed. I had them check them they said they were fine. When I got to looking one had nearly 3 ounces in one spot. Repositioned the tire on the wheel... and all was good.

I do remember knocking a piece off of one of my drums when I was swapping out my axle for a Ford 8.8. I found it swept up in the garage corner... Might JB weld that back on for the weight. Couldn't hurt I guess.

 

[Dirtman]

Might JB weld that back on for the weight. Couldn't hurt I guess.

It could if you don't put it back in exactly the right spot. New drums are like 40 bucks a set, why bother trying to glue them back together...

 

[BlueNostromo]

It could if you don't put it back in exactly the right spot. New drums are like 40 bucks a set, why bother trying to glue them back together...

I'm not talking about a weight on the drums or anything. Literally a part of the edge of the drum. It would fit back just like a puzzle piece. Unfortunately I don't think this little guy is the culprit for everything though.

I went under my truck and shook around the driveshaft all that I could again and didn't notice any movement/play from the u-joints. I didn't bother jacking up the rear end and putting it in neutral to twist it back and forth though.

 

[sgtsandman]

It sounds like a tire issue. Try rotating the tires as suggested above so you can isolate the culprit.

 

[BlueNostromo]

It sounds like a tire issue. Try rotating the tires as suggested above so you can isolate the culprit.

Yeah, really seems like a RoadForce balance would do it for me.

 

[Uncle Gump]

did you look for a wheel that had more weight then the others?

being that it comes in at 55 mph I'm going to say balance is the issue.

Take a drive and get in tune with the vehicle and drive it at speed until you determine where it's coming from. Then rotate that tire to a different corner of the car. Repeat the test drive and see if it moves to that spot.

 

[BlueNostromo]

did you look for a wheel that had more weight then the others?

being that it comes in at 55 mph I'm going to say balance is the issue.

Take a drive and get in tune with the vehicle and drive it at speed until you determine where it's coming from. Then rotate that tire to a different corner of the car. Repeat the test drive and see if it moves to that spot.

Well these tires/wheels have been rebalanced twice so I'd need to check again. I'll definitely see about rotating the worst offender to the front when I figure it out

 

[pjtoledo]

what kind of wheels? steel or aluminum? center cap installs from the rear?

 

[BlueNostromo]

what kind of wheels? steel or aluminum? center cap installs from the rear?

Barts wheels steelies, no center caps, just using stock hub caps

 

[Dirtman]

 

[pjtoledo]

steel wheels aren't exactly flat on the mounting surface.
how you mount the wheel and tighten the lugnuts can distort the wheel.

this is a new Cragar 15 x 8. the outer ring contacts the hub first, there is a gap everywhere else.
at the inner edge is .050", at the bolt hole its .062 (1/16). when the nuts are tightened it pulls the metal in. (duh!)

how carefully the wheel is centered, and how the nuts are torqued in several steps determines
how true the wheel stays.
if you hold the wheel up and crank the first nut to final torque you're likely distorting the wheel too much.

as usual, YMMV