Dunlops Flat Spotting?

[claydoctor]

I have 42,000 on my Dunlops and they have been so-so. Recently due to a move, I have been parking on an aggregate driveway instead of inside the garage. Temps at night are in the 50-60's. When I leave in the morning, I'm on the interstate within about 5 minutes. Some mornings I have no problem at all. Other mornings as I accelerate and reach the 60-65 mph range I get considerable vibration which smooths out around 70. Balance and alignment have been checked and are supposedly OK. Can't understand why this is not every morning. Only thing I can think of is flat spots but why not every morning. Could variations in outside nightly temp have an effect. I'm mystified.

 

[Hank]

I put 48k miles on my Dunlops an never experienced any flatspotting with them. Contrary to what most people think, I never had any problems with them, but then again, I've never been out with them in extreme weather conditions. My AT20s wore perfectly even and had enough tread for at least 10k more miles. I rotated them only twice and ran them at 40/35psi front/rear. Btw, I drive relatively aggressive too.

Since then, I've been riding on the Revos and have experienced flatspotting with the Revos if I don't drive my 4R everyday. It's only noticeable within the first few minutes of driving in the morning and at slow speed. I wonder if anyone else are experiencing that with their Revos? I usually run them at 38/35psi.

 

[blkrnnr]

07 v6 SE 4x4 w/steeringvibration

I am having similar issues to yours claydoctor...
Rig only has 2+K on it and I live in moderate climate atl/ga.
I use 4r as secondary/wkend vehicle.
So for eg if I don't drive it few days then take it out, steering wheel starts vibrating @ around 55mph.
Puzzling thing is, it doesn't vibrate all the time. If I have been riding it for a while, it wont do it. I made sure dunlops had 32psi on them all around. I've never taken it off road, in other words it is pretty much the way it came off the factory.
I am planning to take it dealer today.
Did you get yours resolved?
What else do you know about this condition?

 

[wolfgang]

I thought flat spotting was when you locked up the brakes and flatted a portion of the tire(s) - actually removing a large amount of rubber on the road? (Hard to do with ABS). Radial tires' reinforcement go side to side vice diagonally of old bias ply tires - so when they sit over night (especially in cold), the tires are no longer round. It takes a few miles for them to spin back and warm up back to round. That said Dunlops probably aren't as round even when brand new -- they are a low quality tire compared to say the top of the line Michelin (ha, at 3x the cost!). I'd say at 42k miles ya got you $80/tire worth - not even worth rebalancing them. In past some dealers have agreed to replace Dunlops under warranty - assume due to out of round, out of road force balance or slipped threads --- great deal if you can swing. ONly have 26k on my 03's Dunlops - they need balancing but debatting if its worth it as I eye up the new Michelin AT2 and CostCo's $60 off 4!

 

[loudog2]

I get the same thing with mine. I have a work vehicle which I drive all week. Then on the weekends I drive my 4runner. After driving it for a couple minutes that flat spot feeling goes away.

As for the thought that it only happens when braking, not true. If you leave almost anything stationary, with a couple thousand pounds on top of it. You will most likely get a flat spot.

My nieghbors driveway has bumps from his F350 sitting parked in the same spot.

 

[jwyshrek]

The flat spot problem with the Dunlops appears to be a known problem. In Toyota's TSB (sorry don't have the number onhand) for steering wheel flutter/shake...it outlines that the main cause for such symptons is flat spots with Dunlop tires after sitting for a period of time.

But here's the kicker...instead of just replacing the tires with something else, the TSB fix is to install some 'dampening' parts to the steering system...and even adding weight to the steering wheel itself!

Seems like it would be a less of a hassel to just replace the tires and stop using them all together in new trucks. But I guess they figure that other tires may do the same...

 

[fitzt4r]

I thought it was just my truck. I have the same problem. My 4Runner usually sits for a couple days at a time while I drive my Jeep to and from work. After two or three days of sitting, once I get on the highway, I have the steering wheel shutter for a mile or two at speed.

I personally have had no problems with these tires. They have 22k miles on them and are wearing good. I have noticed some cracks developing between the tread.

 

[claydoctor]

I never had the problem while the car was parked in the garage on concrete, only on aggregate when the car is left out overnight.

 

[blkrnnr]

@ 3K I took it in and dealer said they balanced the tires. And it was fine.
@ 7K same issue again.
Took it in. At first with out driving they checked the balance and said it was fine.
I took it back next day asking them to test drive. They admitted the issue.
It's been two days now truck's in the shop. They said they replaced the front tires and vibration didn't go away.
They were waiting on new set to replace the rears as well.
I am told tires will be comparable to the ones it had originally.
Also paid by service.
I will post what comes next.

 

[olsen_karl]

I noticed the flat-spotting too: 2008 4R, 4WD SR5, 265/65/17 Dunlop AT20s. About 5K miles on the tires.

These are bad, cheap tires. Scary traction in snow, and while they're acceptable for highway cruising in dry conditions, even there the handling is only marginal.

I'll run them in summer until they die (I bought a set of snow tires & had them mounted on a set of Toyota truck wheels I bought off craigslist), but from the looks of them so far, it'll be at around 10-15K miles. The tread on the front tires, at the outer edge, is noticeably worn down -- maybe 1/3 less tread depth than on the outer edge on the rear tires. I haven't rotated them yet, but will do so this weekend.

My wife & I usually seem to get around 40K out of a set of tires, but the roads & conditions where we live also seem to wear the tires faster (winter, rough roads, concrete all-weather highways, twisty mountain roads). It seems that the only way people get 60-80K out of a set of tires is if they live somewhere in year-round warm weather, where they drive a lot of smooth highway.

 

[claydoctor]

I ended up replacing the Dulops after almost 60K miles with BF Goodrich Long Trail raised white letters. Just couldn't see spending extra for the Cross Terrains, particularly, as their raised white letters look dumb and I couldn't go for blackwalls. I have about 5000 miles on them and so far, I am completely satisfied.

 

[blkrnnr]

I got the dealer replace all four tires.
They removed Japanese made Dunlops and replaced with USA made Dunlops.
No white letter walls.
I am not feeling steering wheel vibration, for now.
(I am suspecting they also replaced rims but i can't prove it.)
It's is annoying to have this problem on brand new vehicles. Once dealer service shop starts working on cars no telling what kind of damage they will do.
I have slight markings on the rims now.
And some how my steering wheel is not true any more. I have to hold it may be a couple of degrees to the right to go on a straight line.

Voice in me telling me this is not the end of the story and I will be going back there with the same problem.

 

[wolfgang]

If steering wheel is off center then they messed with the tie rods ends and tow-in/tow-out. Take it back - they can either readjust them both to center steering wheel or pull the wheel and move it on the splined steering column. Some states (PA for one) have hightly crowned roads and to go straight the wheel is probably turned to left slightly. My white lettered Dunlops were made in USA - honestly I don't think replacing them with different country of origin will help for long. Did they replace the spare too - or do you now have non-matching tires? The AT20's are just cheap tires ($90 or so at TireRack vice double that for Michelins).

 

[blkrnnr]

Wolfgang,
Not trying to be nitpicker but yes, I feel they've done smthg w/tie-rod ends and/or as you suggested toe-in/out.
My service paper only tells about replacing four tires. Nothing else.
I don't think it'll warrant pulling steering wheel out though.

No, spare has not been replaced. I've read little about the Dunlop AT20 reviews @ tirerack. Mostly pathetic.
I should have insisted on something different, may be shoulda offered to pay difference for a michelin?
My ignorance in dealing w/dealer I guess
And it took three days for them to get tires replaced.

When I decided on shelling out 35K on a 4R, I thought I was never going to see dealer for anything but required maintenance stuff like oil change.
shame

 

[blkrnnr]

vibration is back

I am taking it back to dealer next week.
Any suggestions to rule out the rim/tire/balance as the culprits?