I have a 2003 petrol with the V5A5 transmission (5ST option code). I *think* its a Jatco, but not sure. 300k km mileage and tranny has always been serviced with Diamond SPIII fluid flush and fills every ~50k kms.
Lately Ive been having an intermittent problem when travelling at speed (>80kph) the transmission feels like it "stumbles" or engine misfires. It almost feels like the front axle is trying to engage. Its a very short, momentary bump in the drivetrain. Passengers can feel/hear it as well. The problem is that its so intermittent, I cannot reproduce it and happens fast and infrequently enough I cant debug it. There are no other driveability issues although my wife reports that maybe the transmission is shifting harder, but I havent noticed that.
So Ive tried a few things including - SPIII ATF flush and fill & gear oil change. Made sure level correct. No metal noted in the fluid. I dont believe its a front axle problem. I replaced the front axle solenoid and was able to get the "stumble" while the truck was in all wheel drive mode. I replaced the oxygen sensors because they were original and the voltage response looked odd. I think the truck runs smoother now, and possibly the stumble happens lest frequently, but I cannot be certain. Ive cleaned MAF sensor too.
I am driving now with scantool looking at MAF, throttle position, RPM. I hope that a stumble happens while Im graphing the outputs from scantool to try to capture something. I have generic scan tool so I cannot read any codes from transmission. There is no codes so I not convinced that its misfiring. I am interested in throttle position because Ive read that the TPS may be potential cause. I am also wondering if the stumble happens because the torque converter is locking out. Again it happens in 5th gear at speed when the throttle position is low. Torque converter problem may be consistent with my wife perceiving that its shifting "harder" perhaps...
I am hoping that you guys might have some more ideas. I know the truck is old with lots of mileage. I just dont want to rebuild if its something cheaper like TPS module or something.
Im also considering throwing in a bottle of lubeguard in the transmission just to see if that ends the problem.
Lately Ive been having an intermittent problem when travelling at speed (>80kph) the transmission feels like it "stumbles" or engine misfires. It almost feels like the front axle is trying to engage. Its a very short, momentary bump in the drivetrain. Passengers can feel/hear it as well. The problem is that its so intermittent, I cannot reproduce it and happens fast and infrequently enough I cant debug it. There are no other driveability issues although my wife reports that maybe the transmission is shifting harder, but I havent noticed that.
So Ive tried a few things including - SPIII ATF flush and fill & gear oil change. Made sure level correct. No metal noted in the fluid. I dont believe its a front axle problem. I replaced the front axle solenoid and was able to get the "stumble" while the truck was in all wheel drive mode. I replaced the oxygen sensors because they were original and the voltage response looked odd. I think the truck runs smoother now, and possibly the stumble happens lest frequently, but I cannot be certain. Ive cleaned MAF sensor too.
I am driving now with scantool looking at MAF, throttle position, RPM. I hope that a stumble happens while Im graphing the outputs from scantool to try to capture something. I have generic scan tool so I cannot read any codes from transmission. There is no codes so I not convinced that its misfiring. I am interested in throttle position because Ive read that the TPS may be potential cause. I am also wondering if the stumble happens because the torque converter is locking out. Again it happens in 5th gear at speed when the throttle position is low. Torque converter problem may be consistent with my wife perceiving that its shifting "harder" perhaps...
I am hoping that you guys might have some more ideas. I know the truck is old with lots of mileage. I just dont want to rebuild if its something cheaper like TPS module or something.
Im also considering throwing in a bottle of lubeguard in the transmission just to see if that ends the problem.
