Harsh transmission shifting

[raedalwan]

Hi All
I have replaced the transmission recently by another used one but with low mileage.
Sometimes I feel harsh shifting. For example while at first gear and RPM raising and for some reason I left the gas pedal I feel harsh shifting to second gear.
What could be the reason

BMW x5 e70 n55
Transmission ZF 8HP45

[yco]

transmission reset may solve the problem or even throttle adaptation reset can help maybe since it wont hurt to try but otherwise it can be a problem in some parts of the mechatronic.. clutch, solenoid etc..

[raedalwan]

Already did the throttle and transmission adaptation reset and am doubt about anything wrong with the new transmission as the millage is less than 10,000Km. Could be the issue related to low transmission oil even very small than normal level?

[Bengineer330]

Had the same issue with my 8 Speed, harsh shifts and jerky acceleration. I thought it was the transmission. Did a fluid/filter change and reset adaptations with no real improvement. Turned out to be the transfer case. I changed the oil and reset the transfer case adaptations. Car is buttery smooth now, 134K on the clock. I used RedLine MT-LV and have about 5k miles on the new fluid.

[raedalwan]

Originally Posted by Bengineer330

Had the same issue with my 8 Speed, harsh shifts and jerky acceleration. I thought it was the transmission. Did a fluid/filter change and reset adaptations with no real improvement. Turned out to be the transfer case. I changed the oil and reset the transfer case adaptations. Car is buttery smooth now, 134K on the clock. I used RedLine MT-LV and have about 5k miles on the new fluid.

Thanks Bengineer330, can you explain more about harsh and jerky shifting like at what speed and gears you are faced such issues and how many liters of oils used for the transfer case?

[Bengineer330]

Originally Posted by raedalwan

Thanks Bengineer330, can you explain more about harsh and jerky shifting like at what speed and gears you are faced such issues and how many liters of oils used for the transfer case?

When accelerating from a stop there was a noticeable clunk between gears and accelerating at any speed it would be jerky as if a clutch was shifting. I did all the transmission work first thinking it was that. When I changed the transfer case oil I honestly didn’t think it would make the difference that it did. HUGE improvement. No more harsh shifts

1-Liter of fluid. I got the special tool from ECS. Took under an hour to do.