[Zed Ed]

Anybody had trouble getting Reverse gear from standstill, whilst on a slope?

Needed to reverse a short distance on a friends , steepish, drive this weekend, and despite, several attempts couldn't get reverse to work.

R showing as engaged on the dash each time.

Observations

a) hill start assist didn't seem to operate to stop the car rolling forward and downhill.
b) because of this, and because of a wall in front of the car, I had to come off the gas quickly, to hit the brake pedal,to stop the vehicle rolling

net result of this is that I very nearly got wedged in the drive, unable to reverse uphill into space needed to get out.

What I think is happening.

- Hill start assist failed or doesn't operate in this scenario.
- Because the car rolled forward and I had little space in front, I came off the gas very quickly, and because of known gearbox hesitation, R didn't have time to engage ( we have all pressed the throttle and seen no response when pulling away from junctions; such that it is possible to press and release the throttle without moving!)

Although I did try and hold the car on the handbrake, with throttle, but it still rolled forward on release, so not sure on the second point!

Assuming there is nothing wrong with my car, then there is a risk, that in a certain scenario you could get stuck

 

[charles charlie]

Possibly you need your clutch settings altered?

I've never had a problem like you describe and my GTR will creep forward in either R or D if I lift off the brake.

 

[LK Drifter]

I had the same thing happen to me just after 1200 mile service. Useing the hand brake made it worse, as it seemed to stop the hill assist working.
I found by putting it back into park keeping foot on the brake, then re-selecting reverse, the hill assist worked as it should by keeping the brakes on for a couple of seconds while reverse is engaged.

 

[henrygggibson]

Hello Ed,

Having to reverse up my steep drive to get car in garage I must say I have
experienced the same problem. I did mention this in a thread back in April.
Having been driving a Mercedes shed on wheels(ML 320) for the last couple of
years I was disappointed that the GTR gearbox did not have anti roll back or anti creep forward. I do not regard a couple of seconds as good enough.
Not so long ago parked in a space which sloped forward towards the kerb.
Trying to get out using reverse and handbrake as soon as traffic had cleared
was a nightmare. Car kept rolling forward towards kerb which would have mullered front skirt. Its bad enogh that it scrapes evertime I reverse up drive as so steep. So Ed, you are not alone! I do not think it is a problem with your car,just one of the GTR gearbox quirks(I know there are many) Hesitation does not only occurr going forwards but backwards.I just wait till it does engage then ride the throtle like a manual clutch for slow manouvres.
Hope this helps. CC should be able to compare as he has ML?:thumbsup:

 

[cracker]

Exactly the same problem. Stuck facing forward on a step downward slope. car would not engage reverse, not matter what i tried it kept edging forward. gave up when i was 12 inches away from the wall at the bottom - absolute shocker!

called the RAC they towed me out, guy said, becasue it was stuck on a steep gradient all the transmission fluid had run to one part of the box, and automatic cut out had engaged!

Still to have my HPC look at the issue, but it is a potential nightmare, let alone very embarrassing!!!

 

[charles charlie]

. CC should be able to compare as he has ML?:thumbsup:

My ML tractor behaves like every other auto except that the car remains stationary for a second or two before creeping forwards/backwards.

That said, my GTR on the same slight incline exhibits the same thing as far as I can tell.

I have read elsewhere that this amount of creep can be adjusted by the HPCs using the clutch settings.

I'd be interested to see if anyone having these issues was to have their settings changed, so we can see if they affect the amount of creep.

 

[henrygggibson]

I can remember sitting at T lights on steep slope in ML. No handbrake on, in D and no roll back at all. Not aware of any time limit such as the GTR.
I was under the impression that the Merc gearbox had an anti-roll back system? Worked for me anyway.
Better than looking a tosspot to passers by thinking you can`t handle the car
cos you are unable to get out of steep parking space.It was embarrsing too, as the car attracts enough attention as it is. By the way CC I got a Laser tester from USA to test that Laser Pro Park instead of Lidar Gun.Seems to work OK.
There was one for hire on E Bay @ £80 a week. When I looked again it was gone!:thumbsup:

 

[mickv]

I've not actually got stuck as yet with the steep incline problem, but on the odd occasion I've had to start on a steep uphill I have found that first tends to engage with a thump and the car lurches forward a bit. That's not a problem if you're just sat at traffic lights but would be a mare if sat in a tight parking spot. I keep intending to go out and practice on some deserted hill like a learner, but keep forgetting to do it. Caretainly, using the handbrake like you would a manual and trying to feel for the box engaging doesn't guarantee a smooth getaway.

 

[charles charlie]

By the way CC I got a Laser tester from USA to test that Laser Pro Park instead of Lidar Gun.Seems to work OK.

Those testers are good for checking head connections but sadly wont tell you whether your setup will resist a rozzer's gun.

Where are you based, as I may be able to meet half way and do some testing.

 

[Rich001]

Just incase it helps when I park facing uphill I find when I restart the car hillstart does not work. I use the handbrake and a few revs as im never too close to another car though.

 

[Zed Ed]

Interesting this has happened elsewhere.

I think I'd accept limitations on low speed / hill manoeuvrability given what GTR is about.

But it ought to be clear what the limitations are.

I'll be avoiding sloping sites for parking and manoeuvres!




.

 

[henrygggibson]

Near Heathrow would be easiest landmark so that would make it about Brummy or Leicester?
Better wait until I bump in to you at a meet(not literally though) as we both have parking sensors now!!
Thanks
H

 

[pimlico]

had the same thing- tried to reverse up a steep driveway and it started to roll forward down the hill.

Only way I could get it to work was to hold it on the handbrake and give it some welly in reverse. Shot out like a rabbit out of a hole - funnily enough my gearbox seems worse after the 1200 service than before.