Engine/Transmission (1998.5 - 2002) 2000 Dodge 2500

[Brando55]

Recently picked up a 2000 club cab 2500 cummins automatic. I noticed while cruising between 50-60 km/h the trans always seems to be switching between two gears. Just wondering if this is normal for these trucks or do I have some trans troubles on my hands?

 

[JR]

Sounds like the torque convertor may be cycling back and forth between lock and unlock. There are a few causes of this but the most commons I've seen is from AC noise being put out by the altenator causes dirty voltage and the TCC to continuously lock/unlock. You need a multi meter that reads AC voltage and take a reading right off the altenator with the truck running. Anything above around 0.1 Volts AC you have failed diodied(s) and a new altenator will solve the problem. This is assuming all your pos and neg cables are corrosion free and ends are clean and tight and good battery voltage. Any of the above can cause random driving issues as well.

 

[Brando55]

Positive cable from the alternator fuse to the battery was in rough shape. Cleaned it up and put on a new battery terminal connector and the problem seems to be fixed. Thanks for the advice