ZF8HP45 Trans temp/ troubleshooting

MattGu40

Private
Jan 29, 2018
36
14
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Ride
335xi FBO
Hi all,

On the wife xhp/mhd flashed x5 N55EWG i started to see some higher Transmission temperature.
on hot days on about 1 hour of spirited driving i can get up to 189F. seems pretty high to me.

i also suspect somme slippage but only in reverse gear which seems strange. when reversing in the quite steep driveway over that little ledge to enter the garage need to rev it quite high.

I have looked at Auto stop and HDC maybe the car was activating brake to prevent rolling away on reverse but i cannot find anything suspicious.

Do all 8hp behave like this?
normal temps ?

Picked up this 2016 CPO at 15k miles and i just keep finding shady repairs done to it. dealer never gave the requested official service history.

Thanks