New Kumhos tracking badly

Submitted: Tuesday, Feb 26, 2008 at 17:25
ThreadID: 54955 Views:1805 Replies:7 FollowUps:13
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Hi everyone just back from tassie. One problem I encountered going down the hume the new rear kumho(825 road venture) tyres were tracking badly wherever the surface was grooved somewhat from trucks. This ment almost constant correction. The vehicle is a 3.5 Jack and was loaded up with camping gear for a fortnight.
I have never encountered this problem before, and am interested in other peoples experiences
Best fuel economy for those interested was 11.6l100 or 8.6ks per l this was on the hume using cruise at 105
Cheers Pete
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Reply By: Notso - Tuesday, Feb 26, 2008 at 18:34

Tuesday, Feb 26, 2008 at 18:34
Have you got enough pressure in the tyres??

Or have you got too much pressure??
AnswerID: 289514

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 19:31

Tuesday, Feb 26, 2008 at 19:31
have tried from 32psi to 40psi which was what it was on trhe trip. Although I did put more in on the return trip and it seemed worse or was I just a bit tired?
Thanks for for your response cheers Pete
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FollowupID: 554815

Follow Up By: Footloose - Tuesday, Feb 26, 2008 at 20:20

Tuesday, Feb 26, 2008 at 20:20
Check those pressures again. My bet is too much air in at least a couple of tyres.
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FollowupID: 554842

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 20:36

Tuesday, Feb 26, 2008 at 20:36
Will do so tomorrow footie. Thank you Pete
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Follow Up By: Footloose - Tuesday, Feb 26, 2008 at 20:54

Tuesday, Feb 26, 2008 at 20:54
I've overinflated before and experienced exactly the same hassles.
Good luck with it Pete.
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FollowupID: 554855

Follow Up By: Gerhardp1 - Tuesday, Feb 26, 2008 at 20:57

Tuesday, Feb 26, 2008 at 20:57
I run 40psi in the Jack at all times. Have done with 3 tyre brands now, never any tracking problem empty, loaded, or with 22ft caravan at 100kmh.

Maybe there's something else wrong, eg a worn suspension bush or something. Shocker rubbers, shockers.
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Follow Up By: Footloose - Tuesday, Feb 26, 2008 at 21:08

Tuesday, Feb 26, 2008 at 21:08
Pete, you said that the rear ones were new? Does that mean that the front ones are worn?
Differences in rolling diameter would certainly cause tracking problems if that's the case. It would be more evident on unsealed tracks.
Is there a great difference in wear between front and back ?Or have I simply mis read your post ?
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Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 22:19

Tuesday, Feb 26, 2008 at 22:19
Gerhardp I was running 40psi
Footie the fronts still had about 60% thread so being a tight arse I repaced the rear hankooks with the Kumhos which are a more aggresivie thread patern. I was hoping to get a few more ks out of the fronts as the the vehicle is only part time 4wd.
THe problem is not so evident on dirt roads, but on sealed roads where trucks have compressed the surface. Was most evident on tar sections of the Hume, no problem on concrete. It may be just a coincidence and a bush may need replacing.
Thanks Pete
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FollowupID: 554879

Reply By: howesy - Tuesday, Feb 26, 2008 at 19:21

Tuesday, Feb 26, 2008 at 19:21
Have your toe checked. Too much total toe in can cause this also
AnswerID: 289519

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 19:36

Tuesday, Feb 26, 2008 at 19:36
Only fitted 2 new tyres to rear as fronts are still 50%. Could this be the problem two diff threads paterns.
Thanks for your responce cheers Pete
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FollowupID: 554818

Follow Up By: howesy - Tuesday, Feb 26, 2008 at 21:06

Tuesday, Feb 26, 2008 at 21:06
swap front to rear and run 40 front 36rear for a while and seee if there is a difference
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Reply By: pop2jocem - Tuesday, Feb 26, 2008 at 19:37

Tuesday, Feb 26, 2008 at 19:37
Hi Madfisher

Did I read your post correctly "new REAR Kumho,s tracking badly"
Do you have these on the front as well? The reason I,m asking is that I have had certain tyres on the front that behaved in a similar fashion, as you say "tracking" but I have never experienced this from any rear tyre even with different brands on the left and right
I may be wrong but I have always been of the opinion that this problem was caused by the front.
Cheers Pop
AnswerID: 289520

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 20:43

Tuesday, Feb 26, 2008 at 20:43
Hi Pop,
This problem has only risen since I replaced the two rear tyres. The fronts are crap Hankooks ats, good road tyre . Their is no problem on smooth concrete roads, mostly the problem occurs in the left lane where the trucks run. Its like someone with a big hand gives the rear of the car a shake side to side
Thank you Pete
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FollowupID: 554849

Reply By: disco driver - Tuesday, Feb 26, 2008 at 20:10

Tuesday, Feb 26, 2008 at 20:10
Hi Pete,
It's probable that the track of the Jack was just that bit different to the groove spacing on the road, this can cause the vehicle to wander around a bit as it rides on and off the grooves.
Does it do it all the time or just on poor road surfaces as you described?

In all probability it only happens when the road surface is showing signs of heavy traffic. Nothing to worry about.


Must admit that I know SFA about Jack's. Do they have a constant 4wd system?

If so, it's vaguely possible that the difference in tyre diameters (old on front and new on rear) could be winding up the transmission a bit and the resultant stress is causing the problem.

Disco.

AnswerID: 289530

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 20:46

Tuesday, Feb 26, 2008 at 20:46
Hi Disco thank you for your response. The Jack is part time 4wd. It only happens where the trucks have grooved the road.
Cheers Pete
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FollowupID: 554851

Reply By: Member - Lost Dog(WA) - Tuesday, Feb 26, 2008 at 20:25

Tuesday, Feb 26, 2008 at 20:25
If the side-wall on the rears is thicker or thinner than the fronts (different strength) this can make the handling erratic also.
AnswerID: 289537

Follow Up By: madfisher - Tuesday, Feb 26, 2008 at 20:49

Tuesday, Feb 26, 2008 at 20:49
I think you might be on to it lost dog. Hankooks on front seem to have soft walls. Their was no problem when I had hankooks on the back.
Thank YOu Pete
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FollowupID: 554852

Reply By: madfisher - Wednesday, Feb 27, 2008 at 08:46

Wednesday, Feb 27, 2008 at 08:46
Just a thought come to mind, this is the first time I have put new tyres on the rear. I did so because the hankooks are so road orientated and I trhought we might encounter wet slushy conditions in Tassie. Which we did , snow arround Great Lake on sunday and blizzards up behind Augusta.
Thanks everyone for their advice
Cheers Pete
AnswerID: 289606

Reply By: Member - Oldbaz. NSW. - Wednesday, Feb 27, 2008 at 17:06

Wednesday, Feb 27, 2008 at 17:06
G'day Pete, never experienced that with my Jack. Currently running BFG A/T on rear ,new, & nearly worn out Silverstone Highway Pattern on front. Hope you can cure it. Your fuel figures
are good. Have you done the restrictor thing? I can only manage
about 12L/100, driven gently (auto)....oldbaz.
PS...run 40 psi all round, all the time.
AnswerID: 289662

Follow Up By: madfisher - Wednesday, Feb 27, 2008 at 21:51

Wednesday, Feb 27, 2008 at 21:51
Hi Baz,
the problem only surfaced when I replaced the Hankooks on the rear. I was running 40psi as we were heavily loaded.
Yes I had the reststrictors removed some time ago and it isw a manual. 12s are good for an auto. If I had slowed to 90 I am sure it would have got under 11, but 800ks is a fair haul in one go so sat on 105 going down and 110 coming back.
Driving arround town today no problem, but I didnot drive down the highway(truck grooves) either.
Thanks for your response Pete
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FollowupID: 555053

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