Ok here it is,Just perchased the truck 1,500 miles ago....
It has been single digits to neg temps her lately and when I start the Blazer(95 LS,4.3 ,auto,163k miles)to warm it up it moves forward slightly?? Doesnt even roll the tires just a little surge ,enough for me to notice standing beside the thing when I start it. Once I have driven it ,stop, restart ,it wont do it again. Only first thing in the morning on really cold mornings??? My girlfriend doesnt even notice it...
The trans up shifts and down shifts fine no surging no hesitations, I dont see any wettness under the truck...No spots, no puddles....
Any ideas on why this happens?Is it a sign of something to come or maybeneeding a service??? The fluid was a quart low but smelled good and was clean...
Any Ideas???
Thanks in advance..

 

This slight movement is due to the residual transmission fluid in the clutch packs that creates a partial apply on start up. This movement is stopped by the parking pawl and/or transmission fluid exhausting completely from the clutch packs.
This slight movement has no adverse affects on the transmission and no repair should be attempted. This condition is normal. This can be verified by comparing with another identically built vehicle under the same cold conditions.
To prevent this condition from occurring, the parking brake should be utilized as per Owner's Manual recommendations anytime the vehicle is parked.

 

Yup, mine does it too. Only when cold out, but it's not only when the trans is cold... Had it do it the other day when I had just gotten home and had to leave on a fire call.

 

Kyle, What FD? I am on the City of Delavan FD, in SE Wisc. Been 10 yrs now. But yes everyone is correct. Heck I cannot even leave a newer Chevy truck/ suv in N while it is running in my bay at work without it creepping forward. What happens is there is always a clutch pack engaged, I believe it is the 1st/ rev clutch pack. That way when you put it into R or D it only needs to engage 1 clutch, not 2. So while the engine is running, ex specially when cold and the fluid is thicker, this will occur, due to the rotational forces from the torque convertor. Korey.

 

Thanks for the information,I feel a little better...
I didnt want to do any damage if it was something I could repair...
As far as the E brake I try not to use it when it is -4 out as I have had brake shoes freeze to the drum before...
Thanks again....

 

Yeah, I came to the conclusion that it wasn't anything to be too concerned about.

I'm in the Fayette Volunteer FD in Fayette, NY (Finger Lakes area). I've been in the fire service for 3 years now consistent. I was always going to calls with my dad when I was a younger though.