[willywi]

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[malicem3]

I believe this transmission's downshifts are a bit jerky especially when going downhill. I don't think a transmission service is changing that.

[scostu]

Originally Posted by willywi

Hi eveyone, so I did a adaptive transmission reset yesterday because the car hesitate to downshift in traffic, after I did adaptive reset the transmission start to jerk from first gear to second it feels like a sudden kick from the back other gears shifts fine. The car is at 90K miles should I do a trans service or it's something else?

Thanks

Are you stock or have you Modded the X3?

Also have you done the transmission service and/or differential yet?

It is highly recommended that the ZF8 transmission be done around 70000 miles.

[SilverJoy]

Willywi, did you do the transmission reset on a cold engine? If you did, i would try to do it again after a short trip so that the transmission oil would be at operating temperature.

[TheCoolX3]

Originally Posted by willywi

Right now I have my fluid and transmission filter changed and all transmission adaptation reset done the car is still jerking from first to second. I'm thinking will updating transmission software fix this issue. Anyone updated their transmission before?

Sounds like a transfer case issue

[najnad]

are you positive the jerkiness is from shifting? You can verify by 1) watching the RPMs when the jerking happens, whether or not they drop at the same time indicating shifting gears. or 2) go into M/S mode and manually shift from 1 to 2 and see if the jerkiness happens at the same time you shift or not. If the jerkiness does NOT coincide with the manual shift (or change in rpms) then its something other than the transmission.

[doru]

Originally Posted by willywi

Hi eveyone, so I did a adaptive transmission reset yesterday because the car hesitate to downshift in traffic, after I did adaptive reset the transmission start to jerk from first gear to second it feels like a sudden kick from the back other gears shifts fine. The car is at 90K miles should I do a trans service or it's something else?

Thanks

I had the exact symptom on an older BMW going 10 years back or so. That car had also a ZF transmission, was a different model, but the symptom was the same. Whenever I pressed the gas pedal to take someone over, it was like a sledge hitting the car from behind - felt it really well in the back of the seat.
I changed the transmission oil and the filter and all was good after that. The symptom started at around 65 k miles. After the procedure, the car felt smooth until I totaled it a few years back. The filter I pulled was black/clogged and the oil was also very dark, almost black. The new oil had the olive oil color, and was genuine ZF. I did the oil change in 2 steps. Drained everything I could, used same old filter and drove for about 2 weeks, then did it again and this time I changed the filter.
The biggest thing is to observe the oil temperature when topping up - you need to use either ISTA or a good reliable infrared thermometer. Has to be done at around 40-50°C, with the engine running. Also, prior to topping you need to work the shifter in all drive modes and reverse, and top up.

The reason you have that "sledge" hitting, is because the converter is probably starved of oil/fluid, is slipping, and once the fluid gets in - it does so suddenly - it engages abruptly. The starving occurs either because the oil level is low, or because the filter is clogged. Don't delay to change the oil and top up correctly if you want to have a lasting tranny. Also, make sure you don't overfill. This can happen at a lower or higher temperature of the fluid.
When overfilled, you can also destroy the tranny due to frothing and pulling foam instead of fluid.

0.02

[Wgosma]

Recently had shop drain/fill tranny and Xfer case- at 73K miles - noticeable improvement in shifting, surprised me. At very low speed, like pulling into garage, I could feel car 'creep' a bit- that disappeared completely after new fluids.

[doru]

Originally Posted by willywi

Humm how do I know it's topped off and not overfill?

You need to raise the car, and be sure is perfectly level. The tranny fluid should be around 40-50°C. So if driven before, just raise it, then wait, but you need a good infrared thermometer if you don't have ISTA to check via laptop the real temp of fluids.
Once the temp is what it should be, the car up and engine running, you slowly take off the fill plug. If the fluid is barely leaking out, it's topped off. If it's spurting out - too much fluid, needs to let go until barely flowing out. If nothing comes out, the level is too low and needs topping.

You need a transfer pump for this.

P.S.: you need to be quick, because once the engine is running the tranny fluid warms up pretty quick. So get familiar with environment and have everything planned up before you start. Because if the temp is too high, you can either lose fluid or add more. You need that temp sweet spot.

[Burnaby]

I know many post suggest to reset the transmission adaptations, but I thing this is not very good idea. However over the time it will get better with the new adaptation values.
What was the reason for the reset? If you changed the fluid you need to level it correctly as overfilling symptom with mine was exactly the same. Procedure begin with cold engine. Level the car, place the oil drain pan, start the engine, unscrew the fill plug and top-up to the max until it drips out. Connect the ISTA and start the procedure. As the fluid gets warmer it will slowly drip out. When the 40 degree Celsius is reached (about 10 min after) it will tell you to tighten the plug back. By that time the excess amount would be out.
In addition VTG calibration can make the things smoother.