Auto boxes & P/N

There have been cases of autos that have been held at high revs for a prolonged period in N or D, sustaining damage.

This can happen without warning, I have heard about complete loss of drive after stationery high revs after a rolling road session.

I think that going between drive and neutral can cause damage due to the ball that seals an orifice being belted against the end of it's travel, so it's recommended to remain in drive when at traffic lights etc.

I feel guilty sometimes sitting with my foot on the brake pedal, as it upsets the driver behind, but you it's better than the car pulling itself down on the suspension with the handbrake hard on.

Andy   West Midlands

Only experience I have had of a gearbox problem relating to leaving it in drive whilst idling but stationary was my Turbo Supra.  It used to be very bad when cold, start the car put into drive and wait anything up to 5 mins for it to engage and when it did engage, the differential got one almighty kick.  The car wasn't too high miles, 160k on a 1991 reg.  After many months of this problem that had stumped everybody, I did eventually find out what the problem was. 

Not sure how the BMW autobox is set up like but the Toyota autobox has a double cooler/intercooler.  Seems the system is at fault.  The fluid overheats when the engine is warm, then overcools when stood overnight.  This in turn messes up the autobox ECU and things start to argue and you don't get to move very quickly til the autobox warms to normal temp.

That is the only problem I have ever come across concerning an autobox.  I can't see how leaving an autobox in drive whilst idling in traffic would do any harm to it, apart from overheat the oil, which would happen anyway regardless of which gear was selected.

Seems far fetched but then, like most things, I guess it is possible that an autobox could have wear problems just like everything else on the car.

If that was the case then surely every time you took the car to the garage for an MOT, the box would suffer cos of the amount of time it remains in park or neutral while emissions are done and all the other checks needed for MOT are carried out with the engine running.

Seems very weird, but then I spose alot also depends on the condition of the box and how well its been cared for in respect to service intervals etc.

-yuk! No wonder it broke....... I bet the filter was clogged too.

-did your car have an FSH? If so, please let us know who the 'servicing' was done by, so we can add them to the list.....

cheers