Reverse to Drive whilst moving - Damage?

Iamzod

Iamzod

Iamzod

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A quick question really, will shifting from reverse to drive in an automatic whilst still moving potentially cause any gearbox/torque converter damage?
I know stuff all about auto boxes.

This is a shift where you get an audible clunk and a slight jolt by the way.

I have been googling but get mixed answers.
 
It would depend on the box, but usually there's a torque/speed limiter that will keep it from engaging. Usually you'd have to be pretty determined to engage reverse in an auto - it isn't like you're always changing gear and just hit the wrong cog?!
 
It's when backing out of the drive, we live on a busy road so the GF always backs out, sticks it in drive whilst moving backwards still & accelerates off.

She went out this morning & came back as the EML light came on when she pulled away & it's stuck in 1st gear, I know it won't fix it but if it's a possible cause for the problem then she really needs to stop doing it.
 
People do that in manual boxes - it is not going to help the box, but at a low speed it won't instantly kill it.

Autoboxes are designed to change between forward (auto), reverse, neutral and park only when the car is immobile. Anything aside from that won't be too good for the internals.
 
Believe it or not she is actually a decent driver, better than half the men I know, she just some has bad habits and drives with no mechanical sympathy whatsoever, probably as she has nil interest in cars & knows nothing about how they work.
 
Ive known a few females treat autos like that. They just dont care.

What car is it? My dad's Mercedes had an engine sensor related issue that stopped the car shifting out of 1st, so its not necessarily a mechanical gearbox issue
 
Matt82 said:
Ive known a few females treat autos like that. They just dont care.

What car is it? My dad's Mercedes had an engine sensor related issue that stopped the car shifting out of 1st, so its not necessarily a mechanical gearbox issue
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It's a Jeep Grand Cherokee which funnily enough has a Mercedes 2.7 5 Cyl Diesel in it, what sensor was it?
 
The worst thing I have done is forgetting to put it in P and putting the handbrake on, and then realising and putting it into P. Then I hear a horrid crunch and some noises like a submarine going too low, it feels like the car is being stretched.

Thankfully only done it about 2 times in 2 years!
 
Well I just found out how to get the dash to display error codes and it showed two - P0703 which I think is related to the brake light fault we had a few months ago which required a new switch this stopped the brake lights & cruise control working.

And P0700 which appears to be commonly caused by a faulty speed sensor on the side of the gearbox, fingers crossed it's just this.
 
I like that my car has syncro-mesh in reverse so I can move forwards, stick it in reverse spin the clutch up a bit and go from moving forwards to backwards, then stick it in 1st and start going forwards again. It's quite fun.
 
FWIW re the shifting while moving thing, I have always done this and I have not had any auto gearbox faults in around 150-160k miles of doing it. I noticed my "father in law" doing this also in his 10 year old (but owned from new) auto too.
 
Can't see it being an issue, the torque converter will take up the slip. If the speed is too much then most box electronics wouldn't allow the shift anyway.
 
Clarkey said:
Can't see it being an issue, the torque converter will take up the slip. If the speed is too much then most box electronics wouldn't allow the shift anyway.
Click to expand...

Certainly with merc boxes (OP says his is a merc engine too, so perhaps a merc box?) the mechanical lockout operates over 5mph anyway, if it was an issue I am sure the lockout would be set even lower.
 
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