2014 gmc 1500 Sierra transmission

Bryan89 · March 3

I have a 2014 gmc sierra 1500. 5.3L. 4x4

Checked the transmission fluid the other day and noticed it has a little burnt smell and a tad brown. Truck has 120,000 miles. I always heard that a vehicle that hasn’t had transmission service regularly, don’t change the fluid bc new fluid and filter will dislodge material and cause more problems. Is that a myth or has someone ran into this problem.

CamGTP · March 3

It still can be somewhat true but on a transmission like yours I wouldn't worry too much about it.

I know on a few older FWD transmission, if the fluid hadn't been touched, you never change it because that is the kiss of death. But those are much older and run different fluids than what is used today.

I'd have no problems dropping the pan, doing a filter and new fluid at 120k. Don't get it flushed, just drop the old fluid and replace with some new fluid to give it more life.

Yotaman · March 4

I would drop pan,change filter , add about 2 gallons and drive a few months then repeat a few times minus the filter each time unless very dirty. Use OEM or REDLINE D6

Yotaman