Rock Climb Issue?

[Zen]

So out with the AJOR boys on Sunday and we all climbing a rock that Wes had pointed out just off the main track... All excpt for my JK which seemed to have issues getting any grip

I put it down to the coopers not expelling the mud and leaving the surface of my tyres like slicks but im not so sure... I was in 4WD Low/ 1st gear and had no problems climbing anything else that day until that point!!

Thomo got this video of the struggle >
http://www.youtube.com/watch?v=j8WPh...ature=youtu.be

Wondering if anyone has any thoughts ideas as to why she struggled?
Cheers
Zen

[wes]

You were getting plenty of wheel spin in this vid too - earlier in the day.

I was in front of you in the TJ and just rolled over everything .

http://www.youtube.com/watch?v=UV1Z8...ature=youtu.be

I don't know anything about the systems in a JK. From a laymans perspective, it looked like you weren't in low range.

[Paul-JK]

What size tyres do you have and what tyre pressures were your running? There was some bagging out of the tyres but not a lot. Perhaps the pressures need to be lower. I have 285/70/17's and find that I need to get mine below about 22psi before it really makes a difference, and that's on a 4dr CRD. You would need to be lower again with a 2dr petrol on the same size tyre.

You did also seem to be getting a lot of wheel spin, as Wes mentioned. Difficult for me to compare the engine revs to the wheel spin though as mine's a diesel auto so I'm not comparing apples to apples. It did almost look like you were in 1st high, or maybe 3rd low, rather than 1st low.

[Mudder]

Zen did you air down? to me it looks like just having not enough traction and you carried very little momentum through it. TJ's are lighter so i don't think you have anything to worry about. Coopers are also made of a pretty hard compound rubber it sacrifices grip but gives a much better life span. Looks to me like you are in low range so I'd put it down to you weighed to much for the amount of traction you had (be from too high pressure or a number of other possibilities) good luck with it though hopefully she doesn't struggle too much in the future otherwise it will be time for a locker or different rubber

[Zen]

Now looking at the video it does look like i have plenty of wheel spin but i was defiantly in 4WD Low/ 1st gear, well the leaver was anyway!!

This sounds stupid but just to confirm, when i have selected Low 4WD my leaver is all the way down (pulling down towards me) & the 4WD light is on dash & ESPOFF light is on dash.

I was also running the tyre pressure down at 15, to low for that rock maybe?
Engine rev is anywhere above 3k in 4WD Low/ 1st gear...

[Zen]

Originally Posted by Mudder

Zen did you air down? to me it looks like just having not enough traction and you carried very little momentum through it. TJ's are lighter so i don't think you have anything to worry about. Coopers are also made of a pretty hard compound rubber it sacrifices grip but gives a much better life span. Looks to me like you are in low range so I'd put it down to you weighed to much for the amount of traction you had (be from too high pressure or a number of other possibilities) good luck with it though hopefully she doesn't struggle too much in the future otherwise it will be time for a locker or different rubber

Cheers Mudder makes me feel a bit better 1st time she has failed me and concerned as to why!! The coopers also let me down, punctured the side wall about 10mins after this rock attempt

[JasperJ]

The wheelspin you see is deceptive as you've got open diffs, when one wheel stops the other goes twice the speed. I'll go with tyre pressure as well as the reason for your woes.