97, automatic, 165k miles
Transmission issue.. on a cold start, not every time - but the colder it is the more likely it happens- until the trans fluid is warmed up a bit (put it in gear but don't drive for a minute- not just the engine idle warm up in park) it will "slip into neutral" briefly, esp if on an incline, or if the fluids are sloshing from coming to a stop. Most times it will find the gear in a few seconds without me doing anything, but sometimes i need to shift it a few times in and out of gears for it to catch up. Will generally only slip the one time as the truck warms up pretty quick. Or as stated before, if i put it in drive (without actually driving) and sit a good 2+ minutes if it's really cold, then it won't happen. Thankfully i live in the south! I'd say if the temp is above 55 i don't have any issues, and temps below 40 i let things warm up long as i can before driving. Really no other symptoms or issues related to this. Going on maybe 4-5 years, it happened once in a while at first, now more often on days below 45 degrees or so. Fluid is clean and at the proper level. My guess is the seals, o-rings, gaskets etc are old and worn out. To tear it open for proper diagnosis is not really feasible as i don't think the transmission needs to be opened unless having a complete overhaul, and apparently the parts are getting difficult to find.. and not too many shops are willing to do it. Thoughts or suggestions?

 

FYI: The "Technical Forum"...then select "Drivetrain Tech", might yield more answers.
When was the last time you had the pan off for inspection?
Members who've decided to go the rebuild route often can't find a shop willing to work on ~28MY old units.

Try a bottle of LubeGard (red). The stuff is cheap, cannot hurt and has helped many.

 

Yeah i figured there might be a better place to post, i wasn't sure.. i changed about half the fluid and filter maybe 4 years ago, and had another complete fluid change (at dealer) maybe 2 years ago. There was another reason for all that at the time, operator error-i thought i ruined the overdrive while towing.. When i did change the filter there was just the sludge on the pan magnet but everything looked okay otherwise. I've considered the additives - but have yet to add any. Not super concerned with the "slip" right now as this is no longer my daily driver.. i figure when the transmission does start to go, just ride till it dies then replace. Not having issues in reverse or after warmed up- once that changes i might begin to worry though!

 

With 'noting to lose', this would be a great time to give it a try.

 

Not a bad idea. I might give it a try. Could be a while before i notice any changes, but I'll come back and update for future readers if anything happens.

 

Update:
I added Lubegard ATF conditioner, and so far it seems to have helped my situation. No slippage in the past couple drives!