Engine/Transmission (1998.5 - 2002) ? Trany

[TY584]

I have a 99 with 68,000 miles on it and just recentally it has started acting funny. The problem is when i am going along at say 1200 RPM and holding it steady the Tach jumps up about 2 to 4 hundred RPM. I feel the truck acting like it is going in and out of overdrive. Doe's this sound familiar to any of you? Thanks for any sugestions.

TY

 

[TY584]

It is not just at 1200 RPM. It is at all RPM's

 

[TY584]

Nobody has heard of this?????????????????????????????????????

 

[rblomquist]

Sounds like the torque converter is locking and unlocking. This is a very common problem if you haven't seen those threads yet. I would start by recalibrating the APPS, it's free and easy to try.



Disconnect batteries for at least 1/2 hour



Reconnect and turn key to on (do not crank over the engine)



Slowly depress the go-petal to the floor and then slowly bring it up to the idle position (do this a few times).



Turn key off.



Start up truck and drive around.



Good luck.

 

[TY584]

Thanks alot i will try that tomarrow.

 

[ToolManTimTaylor]

Could also be:





TSB 18-02-99



Erratic torque converter clutch (TCC) operation.

This information applies to vehicles equipped with a 5. 9L 24-valve diesel engine and automatic transmission built between January 1, 1998 and December 18, 1998. Some vehicles may exhibit a surge-like condition while in fourth gear. This may be caused by the TTC unlocking and locking when it should be consistently locked. The cause of this erratic operation has been identified as electrical noise from the Throttle Position Sensor (TPS) or Alternator. This bulletin involves selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (calibration changes 98cal12 and 99cal14).



Many if not all get the best results from The Happi Box



Simple kit (DIY but you get the idea)



Or DTT's

NOISE FILTER Part # KW5535

 

[Charliegeis]

I took mine to a dealer in Rochester MN. (5 star rated). They put scanner on it and said it needed a new torque converter at $2300 installed. After I read all the info on the problems with torque converters locking and unlocking I cleaned the battery terminals, added a ground wire to the PCM, and wiggled the connectors. I didn't know how to unplug these connectors to clean the contacts. I drove the truck 1500 miles home and had no problems. After reading all the info posted on the TDR web site it left me conviced it was an electrical problem. It saved me $2300.