LOFTY

hello, from over the pond, in the UK.
Just got my unlimited Sahara, 2.8 diesel auto, but two things,

1. in the manual under the towing section, its says "if you use your auto for towing for more than 45 min continuously, then you must change the gearbox oil and filter", is this a printing error???

2. when i put it into low box, the engine speed goes up to 900rpm, so when you put it into drive, i have to put serious pressure on the brake pedal to stop it driving of. My dealer says thats normal, and wouldnt listen to me, so anybody else have this problem???

Cant really ask any UK users, as i am not suppose to have the JK yet, as not for sale until the 4th july, but am doing the Eurojeep camp, so they let me have it early.

Any comments please.

Have a good one.

b1pig

hello lofty..... welcome to the forum.

1- sounds kind of screwey to me. i cant think of many situations where towing would be less than 45 minutes. i'm pretty certain that this is primarily geared towards the auto tranny.... a good look at the tranny fluid would be a good indicatior if it needs to be changed. (burnt fluid)

while i cant speculate on the effects the 2.8 has with transmission options... or capabilities... i cna only guess that it would be similar to what we have here in the U.S.

2- if you are refering to the transfer case... putting it into Low Range, increases the mechanical advantage of the engine. it is easier for the engine to turn the tires... and therefore, it requires more force to counter that improved mechanical advantage.

LOFTY

Thanks for the warm welcome, the main thing that worrys me is the low range.
I realise the gearing will amplify the turning force produced by the torque converter when in low range, but the point i am making is,
Tickover normally 750 rpm, but when you put lever into low range, the tickover increase to 900, and its the extra 150 rpm thats causing the excessive drive.

I believe i have read somewhere, the ecu has 2 throttle maps, one for high, and one for low, so ibelieve the low map is incorrect.

Any thoughts.

Lofty

b1pig

ok, i get what youre saying.

engine idle in gear, in hi range is 750 rpm...
in lo range, it increases?

yea. I'd guess that would be a progamming issue. Since rumor has it that the ECU "learns" as you drive it, I'd give it some time before I went to the dealership over it. It may correct itself. then again, a reflash might resolve it. Not sure how it reflects to deisels.... my only experience with deisel is older Military stuff. you can fix them with bailing wire and a hammer

merfsiu

from a car and driver article:
When you shift into low range, the V-6’s electronic throttle switches onto a more progressive throttle curve. Combined with the 4.00:1 low range, the engine will simply idle up and down astonishingly steep terrain.