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The proper procedure for parking on a hill is to go to neutral, put the parking brake on and then engage park. That way there is no tension on the park rod.

Most of the larger Allison transmissions do not use this type of mechanism, as a matter of fact the Allison’s don’t have park. The reason is this type of mechanism used in the dodge ram has been known to fail. Parked on the hill the vehicle will leave on its own if not properly engaged. On the 48 RE transmission they no longer use shifter rods, they use a shifter cable. The 48 RE ‘s have already experienced the disengaged park mechanism.

I am not trying to scare anyone, but the pocket that the park pawl fits into is a precise fit.


The grinding sound you are hearing is the park pawl tying to engage or fit into the pocket. If the vehicle is in motion or under load it is extremely difficult, hence the resistance or grinding. By slipping into neutral you are relieving the pressure and allowing it to slip into the pocket more easily.

I know the noise is nothing to worry about, however making sure the mechanism is engaged properly is a concern.


This thread just brought to mind when the master builder that trained me Odell had a stuck valve in the governor circuit he would at 50mph try to engage the park mechanism. It would rattle so bad it would unstick the valve. If you had dentures god help you because it would rattle them loose at the same time. I wouldn’t in a million years do that, with my luck it would either engage park or reverse. I still prefer to do it the old fashioned way,take out the valve and clean it. I guess my point is that the grinding is an indication that the vehicle is in motion or the transmission has not fully exhausted all the oil pressure . When we plug the leaks in the transmission it does take a little longer to exhaust the oil.