from your description, it may be a trans issue. check the fluid. when was the last time you service it??

Roy

Answered by ASEMaster6371 (expert)
24,789 answers provided

I just bought the truck it had been setting a few years The trans fluid looks good it shifts fine. I have noticed it seems to do it more around 25mph well today it was doing it around 45mph Would the trany act up just ever now and then like this It could be a week before it does it again, and smoothes out as quickly as it begins

Response from glencroft
1 question asked

sure could. get it checked to be sure by a trans shop to confirm.

Roy

Answered by ASEMaster6371 (expert)
24,789 answers provided

thanks i had an inkling just hoping it's not that

Response from glencroft
1 question asked

It can be the trans but it can be the engine as well. The trans downshifts resulting in the rpm going up but accelerating power is lost then.

Does the rpm shoot up very high or only goes to a certain rpm and holds while the vehicle struggles to gain speed?

Is the MIL indicating and have you checked for trouble codes?
If EGR is used, check that.

Answered by KHLow2008 (expert)
39,806 answers provided