Put car in park take foot off brake and the car leaps forward a couple of inches. I thought this was typical but not so sure anymore. It's actually kind of dangerous and caused me to tap into a few things. Anyone else experience this?

Thanks

 

No, this is incorrect and your dealer should fix it. Park means park, when the selector illuminates the P then the internal brake pawl is supposed to have engaged immediately locking the transmission mechanically. Also, the transmission should come out of gear the instant you pass through neutral so even if the internal brake pawl is not engaged there should be zero drive force. I suspect your shift selector may be defective.

 

I don't have any experience with new-ish Jags so what follows is more of a broad observation to be taken on a FWIW basis.

The amount of "free play", so to speak, in the parking pawl mechanism varies from design to design. In rough terms think of a ratchet with "fine" versus "coarse" teeth.

On my old XJR, for instance, there's enough slack to allow a solid 4"-5" of roll before the pawl engages. Once engaged I can still roll the car forward and back 2"-3". Some time ago I has Subaru customers complaining of nearly twice those amounts....a perfectly normal but perhaps undesirable characteristic of the particular transmission.

My habit, again FWIW, is to always set the parking brake before engaging "P". This prevents any roll and, additionally, always allows easy shifting *out* of "P"...as the weight of the car is being held by the brakes rather than the parking pawl. It also keeps the parking brake mechanism exercised.

More worrisome, to me at least, is your description of "...leaps forward", as "leaps" suggests something other than the car simply rolling until the pawl engages. Are you saying that the the car is still being pushed forward by the drive wheels after "P" is engaged? That certainly wouldn't be normal.


Cheers
DD

 

Doug is right on the money. And i just went and duplicated this in the parking lot by coming to a stop and popping it into park. The faster i did it and the quicker i came to a stop the more it moved after i took my foot off the brake in park. Ide say normal operation, try a differant style of coming to a stop and putting into park and see if you can change the operation

 

If the issue is free roll after selecting P then some movement is normal unless you set the EPB before lifting pressure from the foot brake. Unless parking on the level it is good practice to set the EPB before selecting P both to avoid free roll and to ease release from P when getting going again. The ZF can ping fairly alarmingly if the load is taken by the park pawl in the transmission rather than the EPB. Setting the EPB first before releasing the footbrake is the key to preventing that ping. It is releasing the footbrake that allows the roll rather than simply selecting P so setting the EPB before or after selecting P isn't the key, setting the EPB before lifting your foot off the foot brake is the key.

It's not a bad idea to set the EPB routinely before selecting P. In some countries this is mandatory.

 

Had the same problem when i had my foot on the brake, car lunged forward. Jaguar did not find anything wrong with the car.

 

Any update on 'Leaps'?

On a personal note I always prefer to have the weight of my vehicles held by the reasonably robust brakes, rather than an expensive breakable in the transmission.

Man or Auto, set the parking brake.