2001 X5 After trans flush has shudder symptoms and torque converter not locking up

[vtyagi]

There really is no good answer that I can find about this issue:

1) I changed my Trans oil (purchase the new oil from the BMW dealer based on VIN#)
2) Followed the correct procedure of draining, warming up the engine, revving up the RPM with AC running, filling the trans fluid

Symptoms:

1) No issues when the vehicle has not warmed up.
2) No issues during hard acceleration
3) No OBD Codes
4) RPMs are bouncing up and down about +-50 RPM at any speed
5) Random and intermittent slight shudder which goes away if I accelerate of decelerate

Potential Diagnosis:

1) Could be not enough Transmission Oil? (Added more oil which did not help)
2) Torque converter lock-up solenoid is not locking up because the viscosity of the new fluid is different than the old fluid?
3) Transmission torque/pressure sensor?

Solution:

1) No one has figure it out on the forums. Seems like people are stabbing in the dark with random guesstimates.

Anyone have any suggestions?

Thanks,
Vic

[RRPhil]

Originally Posted by vtyagi

4) RPMs are bouncing up and down about +-50 RPM at any speed

Even if you're driving at a steady speed in 5th gear above 60mph?

Phil

[tmv]

Did you replace the filter as well? ATF needs to be filled in between 35C-55C, IIRC. Warm up engine is too vague for that. I did it on the old 3.0 following GT1/DIS procedure. Car needs to be leveled.
1. Fill the pan until ATF drip out.
2. Close fill-plug temporarily.
3. Start engine and run through each gears, with a few second in each.
4. Measure the ATF temp.
5. Open fill-plug and pump more ATF in (when it's in correct temp range)
6. When it drip out, let it does so for at least 60 sec.
7. Close fill-plug.
8. Turn off engine.

You might not have the correct amount of ATF in there if you didn't fill it at the correct temp. More or less than correct amount is NOT good.

[upallnight]

Sounds like the TCC solenoid in the trans is not working properly.

The purpose of the Transmission Converter Clutch (TCC) feature is to eliminate the power loss of the torque converter stage when the vehicle is in a cruise mode. The TCC System uses a solenoid-operated valve to couple the engine flywheel to the output shaft of the transmission through the torque converter. Lockup reduces slippage in the converter increasing fuel economy. For the converter clutch to apply, two conditions must be met:

Internal transmission fluid pressure must be correct.
The ECM must complete a ground circuit to energize the TCC solenoid that moves a check ball in the fluid line. This allows the converter clutch to apply, when hydraulic pressure is correct.
The TCC is very similar to the clutch in a manual transmission. When engaged, it makes a direct physical connection between the engine and transmission. Generally the TCC will engage at about 50 mph and disengage at about 45 mph.

[SlickGT1]

Sounds like it wasn't filled up properly.

[vtyagi]

Thanks for the replys.

A questions comes to mind:
1) Why did this symptom appear after the drain/fill? I had absolutely *no* issues with my transmission prior to the tranny drain/fill. (now I'm regretting I did it)

As for the amount of fluid in the case, I filled the tranny until it was overflowing and I had to take the tube out quickly and put that nut on it all while the hot transmission fluid was burning my hand. What a lame process.

This has been a very very frustrating ordeal indeed. Somthing as simple as a tranny drain/fill has turned into a freakn' nightmare.

[upallnight]

Originally Posted by vtyagi

Thanks for the replys.

A questions comes to mind:
1) Why did this symptom appear after the drain/fill? I had absolutely *no* issues with my transmission prior to the tranny drain/fill. (now I'm regretting I did it)

As for the amount of fluid in the case, I filled the tranny until it was overflowing and I had to take the tube out quickly and put that nut on it all while the hot transmission fluid was burning my hand. What a lame process.

This has been a very very frustrating ordeal indeed. Somthing as simple as a tranny drain/fill has turned into a freakn' nightmare.

Originally Posted by SlickGT1

Sounds like it wasn't filled up properly.

If you got the transmission that hot that it was burning your hand then the trans was too HOT. If I was to do the trans drain and fill I would drain the trans the day before, let it sit over night and fill it the next day after running the engine for about 5 minutes.

Remember High School Physic things expand when they are heated. So if the ATF in the trans was that hot it has already expanded that you actually refill with less ATF so you are LOW on ATF.

Also what type of ATF did you use? Was it the same as what came with the truck or was it a different brand such as Mobil 1 or Castrol?

[JCL]

Start off by getting the proper amount of transmission fluid in there, when the temperature is as per the spec.

[bcredliner]

This link should help you check your work.
http://www.xoutpost.com/bmw-sav-foru...y-02-4-4i.html

[JCL]

Originally Posted by upallnight

If you got the transmission that hot that it was burning your hand then the trans was too HOT. If I was to do the trans drain and fill I would drain the trans the day before, let it sit over night and fill it the next day after running the engine for about 5 minutes.

Remember High School Physic things expand when they are heated. So if the ATF in the trans was that hot it has already expanded that you actually refill with less ATF so you are LOW on ATF.

Also what type of ATF did you use? Was it the same as what came with the truck or was it a different brand such as Mobil 1 or Castrol?

Agree it was too hot by the OPs description.

If it was low on ATF, then it would be more likely to have a problem when cold. It appears to be OK when cold, but have a problem when hot. That suggests too much fluid, or the transmission being sensitive to the fluid viscosity (lower when hot), or a problem in a circuit that isn't in play when cold.

OP said fluid from dealer.