Transmission shifting erratically
06-24-2017, 07:57 PM
#1
Junior Member
Thread Starter
Join Date: Jun 2017
Location: Lynchburg, Va
Posts: 1
Transmission shifting erratically
Hi everyone. I have a 2009 xB with an automatic transmission. I bought the car used with 60K miles on it. I changed the transmission fluid when I purchased it with Redline D4 ATF. The car now has 90K miles on it. It have recently begun to have a shifting problem around 35mph. It's like it can't decide what gear to be in. The RPMs will drop about 500 and then jump back up 500 a second later. I changed the ATF again and that didn't solve the problem. I also just changed the transmission speed/revolution sensor because I though if it wasn't getting a completely accurate speed reading then that could obviously cause shifting issues. I just took the car for a test drive after replacing the sensor and it is still has the shifting issue at around 35 mph. I have no idea what this could be. Can anyone help me diagnose this issue?
Last edited by MR_LUV; 10-05-2017 at 08:41 AM. Reason: typo
07-02-2017, 02:45 PM
#2
Senior Member
SL Member
Join Date: Mar 2009
Location: Mesa, AZ USA
Posts: 706
When you say changed the fluid with xxx fluid, did you do a complete change or just drop the sump and put about 3 or so quarts back in?
The complete change is quite difficult to do and requires a machine be connected to the oil cooler lines and the engine run so that the original fluid can be pumped out of the torque converter while the new fluid is put back into the system.
For this reason I have always only used the recommended fluid - in this case toyota fluid. When we had a honda we used their stuff (tranny eventually failed thru a design flaw).
There are materials in the transmission that can be affected by some fluids - O-rings, gaskets, fiber clutch discs (if they still use them) and that can stuff things up as well as changes in viscosity. So using the recommended fluid in the tranny is usually a good idea - specially now that we are seeing more and more CVT's. (They are sealing these up now to stop people changing the fluid!!! I wonder why???)
Having said all that, this could be caused by something as simple as a bad ground or an electrical connection that is starting to corrode. Best bet is to see if autozone can get any codes out of the computer (free)
Beyond that, can't really help.
The complete change is quite difficult to do and requires a machine be connected to the oil cooler lines and the engine run so that the original fluid can be pumped out of the torque converter while the new fluid is put back into the system.
For this reason I have always only used the recommended fluid - in this case toyota fluid. When we had a honda we used their stuff (tranny eventually failed thru a design flaw).
There are materials in the transmission that can be affected by some fluids - O-rings, gaskets, fiber clutch discs (if they still use them) and that can stuff things up as well as changes in viscosity. So using the recommended fluid in the tranny is usually a good idea - specially now that we are seeing more and more CVT's. (They are sealing these up now to stop people changing the fluid!!! I wonder why???)
Having said all that, this could be caused by something as simple as a bad ground or an electrical connection that is starting to corrode. Best bet is to see if autozone can get any codes out of the computer (free)
Beyond that, can't really help.
07-09-2017, 08:30 PM
#3
Junior Member
Join Date: Jul 2017
Posts: 10
When you say changed the fluid with xxx fluid, did you do a complete change or just drop the sump and put about 3 or so quarts back in?
The complete change is quite difficult to do and requires a machine be connected to the oil cooler lines and the engine run so that the original fluid can be pumped out of the torque converter while the new fluid is put back into the system.
For this reason I have always only used the recommended fluid - in this case toyota fluid. When we had a honda we used their stuff (tranny eventually failed thru a design flaw).
There are materials in the transmission that can be affected by some fluids - O-rings, gaskets, fiber clutch discs (if they still use them) and that can stuff things up as well as changes in viscosity. So using the recommended fluid in the tranny is usually a good idea - specially now that we are seeing more and more CVT's. (They are sealing these up now to stop people changing the fluid!!! I wonder why???)
Having said all that, this could be caused by something as simple as a bad ground or an electrical connection that is starting to corrode. Best bet is to see if autozone can get any codes out of the computer (free)
Beyond that, can't really help.
The complete change is quite difficult to do and requires a machine be connected to the oil cooler lines and the engine run so that the original fluid can be pumped out of the torque converter while the new fluid is put back into the system.
For this reason I have always only used the recommended fluid - in this case toyota fluid. When we had a honda we used their stuff (tranny eventually failed thru a design flaw).
There are materials in the transmission that can be affected by some fluids - O-rings, gaskets, fiber clutch discs (if they still use them) and that can stuff things up as well as changes in viscosity. So using the recommended fluid in the tranny is usually a good idea - specially now that we are seeing more and more CVT's. (They are sealing these up now to stop people changing the fluid!!! I wonder why???)
Having said all that, this could be caused by something as simple as a bad ground or an electrical connection that is starting to corrode. Best bet is to see if autozone can get any codes out of the computer (free)
Beyond that, can't really help.
Honestly it sounds like one of the clutch packs gave out. And being that this model has a 4 speed automatic that is about the speed it would typically shift into second gear. Had this problem with one of my previous vehicles where it would do the exact same thing. Chances are that it might not be throwing an error code as well which can make it even more difficult to diagnose so autozone might not be able to read the code. Typically you would need one of the expensive scanners that can also read the transmission pressures while hooked up to the OBDII port.
I've seen people go about this a few ways.
1. Replace the part that has given out (usually the solenoid and/or clutch packs to "refresh" the transmission).
2. Rebuild it with all new parts.
3. Replace the transmission with one from Jasper.
I know that none of this is probably not what you wanted to read, but it's something you are going to need to consider especially if you want to keep the car instead of just letting it sit and rot somewhere or selling it.
Feel free to PM me if you need any help.
10-05-2017, 01:33 AM
#4
Junior Member
Join Date: Oct 2017
Posts: 2
Transmission speed sensor caused this on mine tho it also had a error code. Tried cheap $30 speed sensor from Amazon and it was worse. Got a $80 for Intermotor Transmission Input / Output Sensor / Vehicle Speed Sensor Part No SN7138 from advance auto, 10 mins to replace, and xB started shifting normal again.
Last edited by MR_LUV; 10-05-2017 at 08:40 AM. Reason: typo