I have a 2000 sierra 2500 4x4 with a 6.0L and an automatic. The truck is relatively new to me but does have just over 107,000 miles on it. My question for all the wise ones out there is .........I can't seem to feel the lockup convertor locking up on the highway. Is there one in this truck?? It does have the tow package with the 4.10 gears and the rpms aren't too high (2200 or so @ 60 mph) so I was just wondering if this was normal. I don't know much of the history on the truck. Will I be able to tell with a scan tool???

Great thanks to any and all in advance

 

It most likely is locking,or you'd get a check engine light...they are awful smooth nowdays