Auto Gearbox Issues

[pavloh]

Was driving offroad a couple of weeks back at Bendathra Valley in NSW. Some very steep hills in and out of there and had some odd experiences with the auto gearbox. Having never driven an auto offroad before I wanted to see if this was normal.

* In Low Range in 1st gear, just letting the car drive itself down a steep hill with some help from the brakes, as the car gained speed and the revs raised I had a few times where it just poped itself back into 2nd gear even though I had the selector set the tiptronic in first gear,

I found this quite disturbing as if not concentrating the gear change caused a big increase in speed going down hill, which is bad news depending on how steep the hill is and not being able to then stop safely...

My question is, is this normal behavior or is this something I should be taking back to be fixed?

Cheers

[drof]

My 'limited' understanding of the Sport Select mode is that it should hold the gear you've selected, unless you are into the red, and it will then change up to prevent engine damage (excessive revs).

I don't imgine you would have been in the red going down hill though?

[Marty V]

I think you'll find that if you go over a certain amount of revs it'll up change...i think its around 3200rpm so you need to manage your speed carefully with your brakes...

[pavloh]

That is very disappointing not having control of the gearbox in situations where it is very critical to maintaining a low speed.

[Ranger J]

That is very disappointing not having control of the gearbox in situations where it is very critical to maintaining a low speed.

Learn to left foot brake, and 'drive' through the brakes on downhill sections. It's a tricky one to master as you want to avoid overheating the brakes by applying too much brake pressure.

[carl burgess]

Yes i have noticed that with the auto, which is another thing they dont tell you, if you put it in manual mode and drive you will notice it changes gear if you rev it hard enough. Also if in manual mode and you try to change down it wont let you go into 2nd untill your engine speed drops, so realy you dont have full control in manual mode, idiot proof i supose but annoying if you are off roading

[Cadddyman]

* In Low Range in 1st gear, just letting the car drive itself down a steep hill with some help from the brakes, as the car gained speed and the revs raised I had a few times where it just poped itself back into 2nd gear even though I had the selector set the tiptronic in first gear

This is normal and is a disappointment for this gearbox. You do need to manage it with the brakes.

[LukeS]

This is normal and is a disappointment for this gearbox. You do need to manage it with the brakes.

Strange, I have done a fair bit of off roading now in the challenger and have not noticed this.. maybe its my driving style using the brakes more the normal..

[Ranger J]

Yes i have noticed that with the auto, which is another thing they dont tell you, if you put it in manual mode and drive you will notice it changes gear if you rev it hard enough. Also if in manual mode and you try to change down it wont let you go into 2nd untill your engine speed drops, so realy you dont have full control in manual mode, idiot proof i supose but annoying if you are off roading

Guys, these measures are in place so that you don't destroy the gearbox. They are really not that interfering if you drive the car correctly.

-You shouldn't be revving the crap out of a diesel anyway (no power in the top end)
-You will have to use the brakes more downhill to ensure the vehicle doesn't run away - all automatics do this.

[wasarangie]

all automatics do this.

I agree with this comment. All autos I have driven do this, some more exotic "sports" cars hold a gear but in general autos "Know better". The
Manufacturers need to get them to survive the warranty.