Transmission delayed shifting

[Travis Crawford]

Best example, I accelerate to 60mph, set cruise, and the truck will remain in 5th gear u till I reduce my cruise a couple miles per hour. Then it will finally shift to od. 

 

What actions would everyone recommend? No trans dipstick.

[m3n00b]

My 8spd has done this since new.  Even moreso after lift and tires. 

[Travis Crawford]

Yes! I recently installed a 3.5" lift and 33s but I had the truck a very short time before that. 

 

Thanks for your feedback. Makes me think a lewtune will fix my issue. I was concerned it could be a trans issue. 

[Bobaloo22]

I got the Lew’s tune on mine and it made a world of difference, so much better in every way.

[Bobaloo22]

I would also see about a fluid change if you’re over 60 k

[Z45]

Your transmission still thinks it running oem tires.  A truck that has different tires and wheels will have Engine power/performance concerns, Transmission shift concerns, Speedometer registered speed concerns, and Cruise Control concerns.

The Engine Control Unit (ECM) and Transmission Control Module (TCM) use (RPM) and (VSS) inputs as operational parameters for engine torque, transmission shifting, cruise control operation and speedometer indicated vehicle speed.

 

Edited January 23, 2025 by Z45