[peterbilt376x]

hey everybody im new here and new to havin a cummins, ive had some idi turbos but never a DIT. i noticed that when im goin down the highway at 65 it seems like my truck is screemin, it seems like the tc isnt locking in to overdrive but the trans shifts into o/d, i was wondering how i can make a switch for this? its got a new trans and tc, they guy i bought it from did it but im not sure what model trans it is, any thoughts will be appreciated thanks!!

 

[peterbilt376x]

so is it normal for it to seem like its revin high when im goin 65-70 down the highway? i never knew there were od trans w/o lockup. it just seems like if i were to drive this back home(new york) from ohio id go through 200 gallons of fuel

 

[peterbilt376x]

well the sticker under the hood says its got 3.55 rear end