View Single Post
Old 02-03-2002, 04:22 PM
stevebfl stevebfl is offline
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Don't know a thing about mopar but the front pump on all trannies Ihave ever seen including MB is turned by the torque convertor which is spinning every time the engine is.

As Mike says park is just like neutral with the added locking feature.

I suppose that reving the trans in either neutral or park could eventually do damage from reving as the gears are always engaged in an automatic (except Hondas). They use planetary gears which involve three gear groups which are attached to the clutches and drums that are locked in the application of clutches or bands (clutches make two pieces rotate at the same speed - coupled, band stop members relative to the case). Since a reved motor will have clutches spinning in oil against themselves; some plates moving and the others not, they will be wearing some and overheating. At some point the oil left between them acts sort of like the lock-up feature of the torque convertor.

I have never seen any of this do anything to an MB but BMW had a real problem with their mid-80's ZF trannie. Due to internal leakage theforward clutch always had a small amount of pressure on it. I think it was Texas that first found out about this in emissions testing. They were doing in park testing under part throttle conditions. The partially applied clutches burned and wouldn't pull the car out of the stall after the test.

I had the same thing happen on a 86 735 after charging the A/C at 2000rpm in park. We now do this in neutral with the cars wheels off the ground on those models.
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote