Grandtrak A/T 1 failed miserably

Submitted: Monday, Jan 26, 2004 at 20:00
ThreadID: 10033 Views:2149 Replies:4 FollowUps:8
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Here is some feedback on my experience with this tyres, for the benefit of the forum members. I had Grandtraks AT1 for 4 years, 40.000k with only one puncture and excellent wear. I always run correct pressures (depending on the terain) and rotated them every 10.000 k. At 40.000 i had 40% tread left. I just got home from Broome (1200k round trip from Port Hedland) and had 3 Grandtraks from my set FAIL. The tread separation fairlures on all of them (34psi press).
They where failing fo bits all over the tarmac. My recomendation to people here is to stay clear of Dunlops AT1 and AT2.
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Reply By: Diesel1 - Monday, Jan 26, 2004 at 20:42

Monday, Jan 26, 2004 at 20:42
Gday Goran,

I'm currently running a set of Grandtrek AT2's on my Troopy - they looked pretty good on the rack and seemed to be what I wanted for mainly highway use during the Wet. I've only clocked up 25,000 clicks on them and already they are showing a rapid wear rate - I haven't seen any signs of separation yet, but your warning has been noted. I was running BFG muddies before the Dunlops and I had a good run - 90,000 k's.

AnswerID: 44395

Follow Up By: Ridgy - Tuesday, Jan 27, 2004 at 09:17

Tuesday, Jan 27, 2004 at 09:17
Diesel1.....How did you find the noise on the BFG Muddies ? I am about to quit a set of BFG At's - 80000 on a Jack and not even a flat..... will go AT again, but thinking about Mud Pattern.... are they a good idea for 90% bitumen use ?Drag me away from this keyboard.
FollowupID: 306641

Follow Up By: Diesel1 - Tuesday, Jan 27, 2004 at 20:57

Tuesday, Jan 27, 2004 at 20:57
G'day Ridgy,

One of the problems with any big lug mud tyres is excessive road noise on the bitumen. You can eliminate some of it by rotating your tyres about every 5,000 k's, but you will always have a lot of noise. I will be going to BFG AT's next, had em on a previous vehicle when I lived down south and like you, got around 80,000 with no problems. I only went to muddies after moving up to the Top End.

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Reply By: Member- Rox - Monday, Jan 26, 2004 at 23:59

Monday, Jan 26, 2004 at 23:59
Goran, 34psi sounds low I run my tyres to the max (55psi) when on long hiway trips to decrese roll resistance. Think a Bike tyre, flat = hard to push, Hard = easy to push.1991 80Series Std Diesel
2003 Down Under Camper
AnswerID: 44430

Follow Up By: Goran - Tuesday, Jan 27, 2004 at 02:10

Tuesday, Jan 27, 2004 at 02:10
You must be wearing the centre of your tyres really badly or you are driving a dump truck mate. I think the trick is to get even wear on your tyres. Beside, such hi pressures wouldn't do you any good if you had to brake in a hurry.....less contact surface.
FollowupID: 306631

Follow Up By: Member - Eskimo - Tuesday, Jan 27, 2004 at 08:13

Tuesday, Jan 27, 2004 at 08:13
55 does sound a bit high
the original grandtrek were miserable only 30000 and dunlop gave a pro-rata rebate on new .

Wow, am I cute! The extra long legs are built-in prevention against ducks disease. Great looks and a real goer. Doesnt waddle along like some.
FollowupID: 306639

Reply By: Aandy(WA) - Tuesday, Jan 27, 2004 at 00:00

Tuesday, Jan 27, 2004 at 00:00
Helo Goran I have had 3 sets of Grandtreks and averaged 110,000km for each. Never had a puncture or a problem. Mind you I think driving technique and proper care are two keys to long and reliable tyre life. I am always mindful that my tyres are the link between the road and my vehicle. One could have a "Top of the Range" vehicle (which I do have incidentally) and lose all of the benefits through tyre abuse. Read up or talk to others about tyre care and I'm sure you'll get better service from yours in future.
AnswerID: 44431

Follow Up By: Goran - Tuesday, Jan 27, 2004 at 02:21

Tuesday, Jan 27, 2004 at 02:21
I think you must be refering to hiway model of Grandtrak. If you are getting 110.000 from Grantrak AT1 your speedo is faulty or you need to be in the Guiness book of record. Andy, i know a bit about tyres and i assure you that this set of Grandtrak AT1 have been looked after. They have been used off road but not abused in any way. I dont' have "Top of the range" vehicle but mine sees regular off road action. If that qualifies as an abuse than i am glad i am getting BFG AT. I am sure i will be getting better service from my tyres in the future. I will not be buying Dunlop anymore.
FollowupID: 306632

Follow Up By: Member - Bob - Tuesday, Jan 27, 2004 at 09:58

Tuesday, Jan 27, 2004 at 09:58
My LX470 started life with GRANDTREKS. they lasted about 20,000 KM. Then I got Pirellis, they were a bit better. Now I have BFG A/Ts. Very happy so far.Bob
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Reply By: chrisfrd - Tuesday, Jan 27, 2004 at 10:11

Tuesday, Jan 27, 2004 at 10:11
bleep ! 34PSI is very low. Are you American?

The wanker-Yankers love to run very low tyre (tire) pressures like that. I had a trip in the US a few years back and they thought that their tyres were over-inflated at 34PSI!

I pressurise my tyres to 45PSI in a 3.0TDI GU 2 Patrol running 275/70 ish Bridgestones. I've done about 45000K's so far and they haven't been a problem. The idea with tyre pressures is to get the best COMPROMISE. Don't over-inflate, otherwise you will have poor tyre wear (the centres will go out of the tyre) poor wet weather performance. Braking won't be and issue, as the contact patch only varies by about 15% on even the best tyres. (unless they are totally flat)

If you under-inflate, you will have exactly the same problems as the wanker-yankers over in America. Which you did!

Also, remember that inflation pressures and vehicle weights have a bearing on vehicle speed. If you were doing 100Km/h on tyres at 45PSI, expect to only travel at 60-80Km/h at 35PSI and so on, for the same weight and terrain.
AnswerID: 44448

Follow Up By: Goran - Wednesday, Jan 28, 2004 at 00:16

Wednesday, Jan 28, 2004 at 00:16
No, i am not an American. I ran my tyres at 40psi when i first got them, but even at that pressure centres where wearing out fast. That is why i dropped the pressure to 34psi. Wear on this Grantraks is perfectly even across the thread which to me means tyres where not underinflated. I could be wrong about this but in my opinion poor tyre construction is to blame. Consider this, Dunlop Grantrak AT1 Max recomended pressure is 50psi at max load of 1420kg. GVM of my 4x4 is 2200kg.
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Follow Up By: David N. - Wednesday, Jan 28, 2004 at 10:36

Wednesday, Jan 28, 2004 at 10:36
I would tend to agree it's poor tyre construction to blame- that was also indicated by your tyres wearing in the centre at 40 psi.
I also agree 34 psi is LOWWW!
Many people in all sorts of vehicles from small four cyl Front wheel drives up run tyre pressures much too low.
Leaving out soft surfaces such as sand, your tyres will at HIGHER pressures.....
1. hold the road better,
2. handle and stop better
3. last longer
4. handle better in the wet (aquaplaning speed is directly proportional to inflation pressure)
5. run cooler
6. save fuel
The only disadvantage is rougher ride. That is one major reason the yanks run such low pressures.
This all assumes the tyres are built properly in the first place.
FollowupID: 306753

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