Outer Limits 4x4 Board

Hi,
I'm hoping someone can help me. I have a 99 GU patrol. It's a 4.5l petrol, automatic. I'm running 35's and have changed the diff gears to 4.6.
The problem i'm having is when 4wd'ing I sometime lose power. When I say I lose power, basically I can be trying to climb a rock as an example and I will put my foot flat and I just dont have the power there. It might only rev to 2500 or 3000 rpm as an example. It's not it's even turning the tyres at the time, the tyres aren't spinning, my foot is flat to the floor and the engine is just above idle or there abouts. It's happened to me 4 times so far in the last couple of months. The first 3 times where climbing a rock and was at a 20-30 deg angle nose up, driving very slowly and then put the boot in to get some power and traction and got neither. The last time I was in reverse and was reversing back up a very small hill in some mud and again, foot to the floor and the power just wasn't there.
The car is regularly serviced with engine oil, filters, coolant etc. I was thinking perhaps getting the auto gear box services and replacing the spark plugs, would that help at all?
I'm at a bit of a loss at the moment and need the vehicle in about 2 weeks time for a 1 week trip.
Thanks in advance for your help & sorry of the long post.

Rojer

the auto could be low on ever so low on fluid and the diffrent angel could be causing the auto to slip. defentely get the auto serviced

Jake GQ.. wrote:the auto could be low on ever so low on fluid and the diffrent angel could be causing the auto to slip. defentely get the auto serviced

If the auto is low the motor should rev and you still go nowhere ie no drive. I'm affraid I can't suggest the cause though... but I doubt its low auto fluid... maybe it's hooking up too hard and the motor hasn't got the pills to drive it. Just off idle and a bootful on a steep incline... tho I would have thought in the mud/small hill you describe it should have spun 'em up easily.. sorry that's about it..

your hand break isnt sticking is it. I had this happen on my range rover it was full of mud i only realised after i was on slight decline and it wasnt easing itself foward as autos do.
This also was intermittent.

Cheers Damo

RED60 wrote:

Jake GQ.. wrote:the auto could be low on ever so low on fluid and the diffrent angel could be causing the auto to slip. defentely get the auto serviced

If the auto is low the motor should rev and you still go nowhere ie no drive. I'm affraid I can't suggest the cause though... but I doubt its low auto fluid... maybe it's hooking up too hard and the motor hasn't got the pills to drive it. Just off idle and a bootful on a steep incline... tho I would have thought in the mud/small hill you describe it should have spun 'em up easily.. sorry that's about it..

It should have the guts to drive it though, other times you can put your foot down and the power is there. Thanks for the input anyhow.

UrbanRedneck wrote:your hand break isnt sticking is it. I had this happen on my range rover it was full of mud i only realised after i was on slight decline and it wasnt easing itself foward as autos do.
This also was intermittent.

Cheers Damo

Nope, handbrake isn't stuck on. It does edge itself forward as per normal.

Could the spark plugs make a difference ? I suggested the spark plugs because maybe it's not getting enough spark ? I'm just clutching at straws here.
Thanks for all the help so far.
Rojer.

i got the auto rebuilt in my daily drive and when i got it back it would slip when you turned a corner sharplel the machanic checked the fluid and it only took about 300ml of fluid to fix the problem. i would defently check it anywhay. good luck