This Isn't making sense if the damn things are in gear there's really no way they should move. The only reason to apply the brake is to take load off the gear. Is it possible the thing's pop out of gear just sitting there?

 

i always put the wheel hard over on an incline so that if something like this happens it rolls up against the curb.

havent had this happen yet tho

 

OK, you did not mention if you had a manuel or auto trans.

At this point i'm assuming a manuel. When just left in gear you are depending on the engine compression to hold you in place. This is why you have a parking brake, adjust it and use it. Unless you are on a extreme incline the motor compression should hold it, if you are on a slight incline you have issues internal the motor, meaning a compression leak... head gasket, piston rings, valve seats.

With an auto trans there is a parking shaft that engages a parking collar on the transmission output shaft. So in this case if the engine compression is lost it will be very difficult to move shifter from P to D. Because of the pressure on the parking shaft/collar. Also you are suppose to set parking brake first, then put trans in Park, along with turning tires into the curb or uphill.

One more thing, with a manuel park in the lowest gear. If you use a higher gear with the mechanical leverage of the jeep weight it will turn the motor over even with a perfect motor.

 

Everything you wrote is true, and well written.
This is basic stuff. I hope your answer gets a lot of exposure.

 

lolz

 

I had the same problem. I need to make sure I leave it in 1st gear when parking on an incline.

 

....and set the brake, too.

 

My parking brake just broke over the weekend! I went to pull up on the level and then a loud slam and the level dropped down. Other then screaming and swearing, I thought a cable snapped. After looking at the under side and finding nothing wrong, I took apart the entire console. Ended up being a metal coil then runs into a bracket that is riveted that runs along the parking brake lever. Called the dealer, and they replaced the entire unit under warranty. Took them 2 days to do the work, they had to order a new unit for me.

I'm looking forward to having to have it adjusted in a few months so my jk doesn't roll like yours

 

Bringing back an old thread.

My e-brake snapped last night and while in 1st gear, (manual trans). the Jeep started to roll back down the driveway. like the OP said, every 30 seconds or so, it would jump (or roll) back more. tried reverse also and the same thing.

My driveway is not that much of a slope, I would have assumed the engine could hold it in place????? It's at the dealer now for the e-brake (warranty) I asked them to look into why the engine would not hold. (only 2K KM left for the warranty).

 

I'll agree to the above as well..
And add a story...
My old 86 F150, 4x4 was parked on a very,very, very... I mean 1% grade... Front end facing down hill... I parked it, put it in gear, and hit the parking brake... Ran in side to grab something, ran back out (maybe 3-5 minutes max) and my truck was gone... I must have had one of those looks on my face because this old lady that was on the porch across the street asked if that was my red pick up. I said YES (Exasperated) and she just pointed down the street...I ran probably a football field away to find it's driver side wheel sitting on the passanger seat of a Dodge Daytona... The driver was inside looking a little freaked out. I checked to see if he was ok, then went over to my truck and unlocked it... got it... everything was in it's right place... In gear, braked... everything... It turned out after a little investigation by the police, that the parking brake was not connected. So, when I pushed it in nothing was happening to the breaks... I had just come from Pep-Boy's, had the reciept to prove it. They had just serviced the brakes and didn't re-connect them correctly. The engine had a slow compression leak... most of the trucks of that day do... So, end of story, I didn't get a ticket, and learned about brakes, compression, and that service shops are legally bound to inspect brakes prior to them leaving the shop...