Truck Rolls Forward When Facing Downhill in Reverse

Alright, I have a 2009 DCLB 4x4 that has 120k on it. Today, I was going to back up my driveway and I put it in reverse and went to hit the gas, and before I hit the gas, it began rolling forward. It's never done that before. After backing up the drive, I pulled back down and was able to recreate the same scenario with the same outcome.

Transmission hasn't been serviced, ironically, I have an appointment Monday to have that completed.

What could the issue be here? Thanks

 

Wait. You mean, gravity still works?

Could be low on fluid however, if it's never been serviced, might consider doing a full proper fluid change

 

Maybe the earthquake shifted your driveway to a steeper angle.

 

Previously, it's always stopped itself, probably due the pressure that the torque converter is/was able to build.

 

I don't think I've ever owned a vehicle that didn't do that.

 

Same, seems normal OP.

Hell, my subaru with electronic parking brake has a mode for stop and go driving on a steep hill where it'll reapply the parking brake every time you stop, so you don't roll backwards (very specific feature I might add).

 

Check to see what the rpm's are supposed to be when it is in gear. Then check to see what your rpm's actually are when in gear. That is a starting point.

 

Sounds normal to me...

 

Sounds normal 2 me too. When in that situation I always use foot on brake and foot on gas to prevent rolling. My wife always does this in her car and then when I drive it I do the same thing she does without rolling. She just can’t understand why it rolls with her and not me.

 

When you reverse out of a parking space (or drive way, etc) and then shift into (D), do you stop fully or let the truck roll back WHILE you're shifting it into D?

 

Every vehicle l have ever owned has done the same thing.

 

Facing down hill, putting it into reverse and then rolling foward is the same as.. facing uphill, being in drive and then rolling backwards

Happens to a lot of people including me, try the brake thing @maxtherat suggested.

 

I really can't believe anyone would think this is even a problem. Do they not teach gravity in school anymore?

I find this as silly as those clutch switches in order to run the starter.

Or in a manual transmission that has a brake that holds the truck when starting from a stop. Hill Start Assist I think.

Learn to drive and none of these are an issue.

 

My truck has always rolled on incline like that. Gravity is a bitch sometimes.

 

Point being is the OP said that it has never done this before meaning that he believes something is amiss because it is doing it now. My ford will hold its own in the same situation on a 30 degree downhill slope when in reverse. It might slowly creep forward but it willl not just "roll" foward. Low transmission fluid will cause it to go into gear slower. Maybe it didn't engage quick enough before he took his foot off of the brake. Low RPM's can cause this too.

 

Leaning towards normal too. These truck don't hold their position on inclines/declines.

 

You're supposed to use the brakes to hold a vehicle on an incline or decline. If the transmission is doing it while in Drive. It's building up a lot of heat, as it's the fluid pressure doing it.

 

Right. But we are only talking a few seconds in this situation.

 

A few seconds won't matter. l just mean if people do it too long because they become used to it. l had a friend that always did it. He'd let the vehicle hold itself on slight inclines for a whole traffic light, or if stuck in traffic.

 

Yeah, that ain't good.