vibes at 80+ mph, are my expectations off? Tire balance question

[bdog1]

Really. Sell the truck 'cause of the tires?

Get a force balance. It will tell you the tire build quality. (Over 25# is not going to meet you expectations.) Check the radial run-out. You can do this yourself. Basically how round is your new tire? You CAN balance an egg shaped tire, but it won't ride well!

How's you rim offset? All tire issues are amplified by giving them leverage against the suspension. You want the center of your rim to be the same as the center of the stock rim.


Sent by wing, prayer & ATT

 

[mapper]

Really. Sell the truck 'cause of the tires?

Get a force balance. It will tell you the tire build quality. (Over 25# is not going to meet you expectations.) Check the radial run-out. You can do this yourself. Basically how round is your new tire? You CAN balance an egg shaped tire, but it won't ride well!

How's you rim offset? All tire issues are amplified by giving them leverage against the suspension. You want the center of your rim to be the same as the center of the stock rim.


Sent by wing, prayer & ATT

The tires were force balanced. I have stock rims.

No, not sell the truck because of the tires. I bought the thing on a whim and in many ways it doesn't meet my needs very well. I'm speaking along the lines of not digging deeper only to sell it anyway. I really, really get irritated by shimmies on the freeway...If I can't drive it over 70 it's pretty much useless to me as I have a nice commuter car for the in town stuff, and two other good travel vehicles. I need to sell at least one anyway. At the moment, given my general mis-givings about the usefulness of the platform (for my personal needs, not others) I'm not that keen on rebuilding the the drivetrain...as I very well may end up selling it anyway.

 

[bdog1]

There 31x10.50 right? How wide are those stock rims? Original tires are 255? 265? You may need to experiment with (less) air pressure. How much of a "bow" is in the tread area? Does the tread contact all the way across? This is a common issue for Wrangler guys.

When you do the brakes, before you pull the wheels, spin the tire just slightly off the ground and measure the run-out.

Just taking a WAG... Wobble, low speed, is out of round front tire. (You say it's better now, so it may have been moved to the rear on that second visit?) Vibration is coming from rear. As a rule if you can"drive through it" it's balance, if it stays it's out of round. I don't know much about that tire, but I'm skeptical (by nature).


Sent by wing, prayer & ATT

 

[mapper]

Yes,
31x10.5 on 15x7" wheels. Stockers were 265/70 15s, I believe.



I've tried running at 35 and 38 psi. 35 is what the charts tell them at Discount. I haven't googled charts on my own yet but I imagine they've got proper charts. Tread contacts all the way across while sitting still (static). Not sure about while rolling.

I had a slight wobble (I'm pretty picky) at 40-45 mph earlier in the week. That went away after I tightened up front bearings (last night) and BEFORE the most recent rebalance (today) .

The LF tire had the obscene weighting, they did move it to LR and it sports something like 25g (total) now vs 70-90g (previous) on both inside and outside.

Good idea on checking for egginess when I jack it up for brakes. I'll probably put the whole truck on stands tonight so it will be a good time to do that. I did ask them on each previous visit to let me know if they suspected the tire...I did NOT buy the tires from them. So, I'd guess they would happily tell me it was a bad tire if they really thought that was the case. It's kind of funny I've been almost hoping my mechanics would tell me suspension shot or these guys would tell me the tires are shot...BUT instead they all say they can't find anything to sell me.

I know my rotors are warped/not smooth all around...probably most in the rear. Hence my feeling that maybe they are inconsistently dragging a bit and it becomes most apparent at high speed. Seems a long shot, but possible.

I'll try harder to pinpoint vibration but if I have to choose an axle I'm inclined to say rear as I feel it as much in the butt as the steering wheel. That said the whole truck seems to shudder which has me all worked up about u-joints, driveshafts, bearings...etc. etc. etc. Hence my previous comments about throwing in the towel on this one

Brake job will take a bit as I'm waiting on rear parts that I thought I had ordered but apparently forgot to hit "submit order"..so I just ordered all that kit today.

 

[mapper]

Per my commute home:
Definitely worse now than it was at any other point in this process. Messing with tires is changing the situation' but not for the better at this point. Going above 70 is no fun at all. Definitely more in the butt/whole vehicle than the steering.

 

[mapper]

When you do the brakes, before you pull the wheels, spin the tire just slightly off the ground and measure the run-out.

Did this after work. One rear tire (the one with all the weights on it previously on the front) had a "high" spot (tread further out from the center) for almost 90 degrees of rotation. The other 3 were fairly consistent except a small "low" spot in each that could correspond to where it had been parked. I marked the spots, put the truck back down, and drove it to take dogs out for a run.

After dinner I jacked up all four corners again, using same procedure. The one tire with the "high" spot still indicated a high spot in the same location. The other 3 each still had a "low" spot, but it had moved....suggesting my previous theory of that "low" spot being where it sat before I jacked it up.

I think we may be on to something with this one "high" spot tire. The guys at discount had marked that tire already...their mark was exactly opposite where I measured the spot.

 

[All-Terrain]

Can they not balance the tires for a specific speed? In other words, maybe your tires are only balanced to 75mph, when they should be balanced to 90mph, for example?

I have 31x10.5x15 BFGoodrich All Terrain T/A KO's on my Montero that I bought about 4-5 months ago... purchased from Discount Tire... they definitely used more weight on them than I thought should be necessary. I also bought 265/75/16 Yokohama Geolandar AT-S's for my other big SUV, from Discount Tire, and the kid (yes, kid) who did the balancing just kept adding stick-on weights to the point where I started to wonder if my brake rotors were going to fit behind the wheels...

Discount Tire has never damaged a wheel, after buying many sets of tires from them over the years... and they have always beaten everyone else's prices, including Tire Rack.... so I keep going back to them. However... their balancing sometimes leaves a lot to be desired. I really wish they would make an effort to spin the tire itself around on the wheel to help balance out the tire/wheel combo, rather than using so much weight. It has a lot to do with the person/kid/gorilla doing the work.

But then, that's why I do so much of my own car maintenance. I don't trust a soul.

 

[Sabre]

I've had very similar symptoms when a u-joint was installed out of phase. Warped rotors could certainly be contributing to the problem. High spot on a tire amplified by bad shocks? Simple stuff but very frustrating!

 

[rxinhed]

Ever consider that Monteros weren't supposed to be an 80 mph vehicle? I know they'll do that, but still.

If you want to maintain the high speed driving, consider a street tire rather than all-terrain. The Michelin tires are generally a high quality product.

Try lowering the air pressure in your existing tires?

The high 30s inflation may simply be picking up mechanical erosion of the road bed itself. Asphalt overlays on most highways are either 1/2" or 3/4" aggregate, base courses can be 1". As the emulsion (bituminous asphalt) wears away, there are voids in the tire / road surface that you can feel transmitted through the steering.

 

[mapper]

Ever consider that Monteros weren't supposed to be an 80 mph vehicle? I know they'll do that, but still.

Yes, In fact that was the initial question I posed in this thread. Hence the title about my expectation.

If you want to maintain the high speed driving, consider a street tire rather than all-terrain. The Michelin tires are generally a high quality product.

Again, part of my original question. Most people seem to think an A/T can handle this speed fine. I have a smaller A/T on my Astro, a Cooper, also drives great. But Michelin definitely has a reputation for quality. I usually run Nokian tires, never had a bad tire from them. If I decide to get a whole new set I'll probably get some Rotiivas

Try lowering the air pressure in your existing tires?

Definitely a consideration though I don't like the thought of running an underinflated tire. I hate vibrations but I hate blowouts even more.

The high 30s inflation may simply be picking up mechanical erosion of the road bed itself. Asphalt overlays on most highways are either 1/2" or 3/4" aggregate, base courses can be 1". As the emulsion (bituminous asphalt) wears away, there are voids in the tire / road surface that you can feel transmitted through the steering.

Definitely good consideration but this goes well beyond transmitting road imperfections. Per the last balance, the minute I tick over 65 the truck starts shaking. Above 70 the windows, if down, are rattling in their tracks, by 75-80 I was actually concerned the windows might break. Definitely the balance plays a role and this this last balance I got was, by far, the worst. Sadly they had put their "best guy" on it.

After I'm done with the brakes and sway bar links I'll give the Discount guys another shot and I'll consider buying another tire...and transferring, the one troublesome tire, to the spare.

 

[mapper]

I've had very similar symptoms when a u-joint was installed out of phase. Warped rotors could certainly be contributing to the problem. High spot on a tire amplified by bad shocks? Simple stuff but very frustrating!

I've definitely considered pulling the driveshaft to get it balanced and have new u-joints installed...Would first like to rule out tires/brakes. Trying to deal with one component at a time so I can see where the problem actually was.

 

[mapper]

Can they not balance the tires for a specific speed? In other words, maybe your tires are only balanced to 75mph, when they should be balanced to 90mph, for example?

I have 31x10.5x15 BFGoodrich All Terrain T/A KO's on my Montero that I bought about 4-5 months ago... purchased from Discount Tire... they definitely used more weight on them than I thought should be necessary. I also bought 265/75/16 Yokohama Geolandar AT-S's for my other big SUV, from Discount Tire, and the kid (yes, kid) who did the balancing just kept adding stick-on weights to the point where I started to wonder if my brake rotors were going to fit behind the wheels...

Discount Tire has never damaged a wheel, after buying many sets of tires from them over the years... and they have always beaten everyone else's prices, including Tire Rack.... so I keep going back to them. However... their balancing sometimes leaves a lot to be desired. I really wish they would make an effort to spin the tire itself around on the wheel to help balance out the tire/wheel combo, rather than using so much weight. It has a lot to do with the person/kid/gorilla doing the work.

But then, that's why I do so much of my own car maintenance. I don't trust a soul.

This is my concern. While I've generally had very positive experiences with discount, I've recently had problems with them getting balances right on other cars. I've had 6 different cars (between me and GF) in for tires/balancing in the recent past. At least they keep trying, I give them a lot of business.

 

[FordGuy1]

You would be better served by finding a competent tech who can diagnosis a vibration. It's fairly easy to tell based on rotational speed if its tires or u-joint issues, just as a good tech can tell you if a engine knock is crankshaft or camshaft speed.

 

[mapper]

You would be better served by finding a competent tech who can diagnosis a vibration. It's fairly easy to tell based on rotational speed if its tires or u-joint issues, just as a good tech can tell you if a engine knock is crankshaft or camshaft speed.

Quite right. This started as trying to see if tires needed to be rebalanced and is snowballing. I'd like to get the tires situated before getting further in. My gut and/or butt, I suppose, tells me the tires are a major issue. Got it all apart for brakes at the moment (needed regardless) and I'm still waiting on parts.

 

[PirateMcGee]

Going to go a bit against the grain and actually suggest selling the truck. While it is perfectly capable of 80mph+ it's really not a vehicle best suited to the job as you already know. Plus "pretty much useless to me as I have a nice commuter car for the in town stuff, and two other good travel vehicles". From that I am assuming the Montero is a 4th vehicle. That's too many in my opinion. 1 commuter and 1 4wd/fun rig is plenty enough work/money pit. I would sell the Montero and your other least favorite.