Transmission Jerk

RuskiE39 · #1 06-20-2021, 11:21 PM

2011 X5 35d, recently got it tuned/deleted and just got around to trying it out in the sport mode (2 weeks later). I noticed that under light acceleration the shift from 1st to second is rough. It’s hard to explain because it doesn’t make a sound or feel like it’s doing any damage, it just doesn’t feel smooth. Doesn’t seem to do it if I do a hard acceleration.

Mileage is 117k and i know the PO had the tranny fluid replaced before I bought it by his indie/dealer. Is this something that would be remedied by a transmission tune or something else?

TIA

andrewwynn · #2 06-21-2021, 12:47 AM

What scanner are you using? Real-time solenoid pressures/mA current can be compared.

RuskiE39 · #3 06-21-2021, 01:12 PM

Quote:

Originally Posted by andrewwynn

What scanner are you using? Real-time solenoid pressures/mA current can be compared.

No scanner / monitoring equipment.

andrewwynn · #4 06-21-2021, 01:59 PM

Time to get one. I use foxwell nt510. You're literally driving blind without the needed feedback.

aureliusmax · #5 06-22-2021, 04:35 AM

Quote:

Originally Posted by RuskiE39

2011 X5 35d, recently got it tuned/deleted and just got around to trying it out in the sport mode (2 weeks later). I noticed that under light acceleration the shift from 1st to second is rough. It’s hard to explain because it doesn’t make a sound or feel like it’s doing any damage, it just doesn’t feel smooth. Doesn’t seem to do it if I do a hard acceleration.

Mileage is 117k and i know the PO had the tranny fluid replaced before I bought it by his indie/dealer. Is this something that would be remedied by a transmission tune or something else?

TIA

To me sounds like the tune included transmission software to increase the transmission line pressure to maximum. This increases line pressure on the clutch apply and release so they don't slip as much when changing gear, making the clutches last longer and be able to accommodate the increase engine torque.

Myself I prefer the feel of maximum line pressure.

ard · #6 06-23-2021, 02:29 PM

Quote:

Originally Posted by aureliusmax

To me sounds like the tune included transmission software to increase the transmission line pressure to maximum. This increases line pressure on the clutch apply and release so they don't slip as much when changing gear, making the clutches last longer and be able to accommodate the increase engine torque.

Myself I prefer the feel of maximum line pressure.

lol

thats what it sounds like???