Transmission Shifting Concern When Cold On A 1999 Silverado Z71

famouslee99gt · January 12, 2009

I have a '99 Silverado Z71, 5.3L AT, and it seems that in the winter, when the truck is cold, the shifting pattern is different. It will shift into 2nd ok, but it will rev out pretty far for 3rd. It seems that it only does it when real cold and doesn't do it when the truck is warmed up. Are these trucks set up for the transmission shift pattern to assist in warming up the motor quicker. I know of some Fords that are set up that way. I talked to my local tranny shop and he wants me to drop it off for him to take it for a test drive sometime. Oh, this is my 3rd winter with the truck and it has done it ever since I got it during the winter. During the summer it is normal.

Thanks

jrrod2004 · January 12, 2009

I have a '99 Silverado Z71, 5.3L AT, and it seems that in the winter, when the truck is cold, the shifting pattern is different. It will shift into 2nd ok, but it will rev out pretty far for 3rd. It seems that it only does it when real cold and doesn't do it when the truck is warmed up. Are these trucks set up for the transmission shift pattern to assist in warming up the motor quicker. I know of some Fords that are set up that way. I talked to my local tranny shop and he wants me to drop it off for him to take it for a test drive sometime. Oh, this is my 3rd winter with the truck and it has done it ever since I got it during the winter. During the summer it is normal.

Thanks

GM's Delayed Shifting that is built into the trans program when it is a certain temp. Allows the engine to reach operating temp alot quicker.

jrrod2004 · January 12, 2009

I would have him drop the pan just to make sure, but it should not be anything major - based on your description

famouslee99gt · January 12, 2009

About 2 yrs & 2 mons ago I had the transmission serviced, which was about 15k miles ago. I actually had them do a service, install a Corvette Servo, and also turn up the pressure solenoid? inside the transmission to increase some line pressure and make shifts a little bit firmer. I pulled some trailers occasionally and also plow snow. I don't plow snow hardcore. The truck has 123k miles on it and I was hoping that it wasn't something terrible because I really don't want to have the thing rebuilt

jrrod2004 · January 12, 2009

About 2 yrs & 2 mons ago I had the transmission serviced, which was about 15k miles ago. I actually had them do a service, install a Corvette Servo, and also turn up the pressure solenoid? inside the transmission to increase some line pressure and make shifts a little bit firmer. I pulled some trailers occasionally and also plow snow. I don't plow snow hardcore. The truck has 123k miles on it and I was hoping that it wasn't something terrible because I really don't want to have the thing rebuilt

transmissions can be tricky to diagnose over the net, but if it does not exhibit the condition any other time out of the year, then typically this is what the 'problem' is. I know because we have had two really cold days out of the year last year and my truck did the same thing until it was at operating temp. I only recommend to have him pull the pan to make sure there is not alot of shavings, of which can indicate a bigger problem.

famouslee99gt · January 12, 2009

Thanks. That makes me feel a little better. I figured if it's been doing it for 3 yrs now and old when it's really cold, then it must be ok and just how they are designed.

dlstewart01 · January 12, 2009

About 2 yrs & 2 mons ago I had the transmission serviced, which was about 15k miles ago. I actually had them do a service, install a Corvette Servo, and also turn up the pressure solenoid? inside the transmission to increase some line pressure and make shifts a little bit firmer. I pulled some trailers occasionally and also plow snow. I don't plow snow hardcore. The truck has 123k miles on it and I was hoping that it wasn't something terrible because I really don't want to have the thing rebuilt

I have been running a Corvette servo for 3 years with no problems. When you crank up the line pressure you should just turn it up in small increments.. If it has been doing this for 3 years I wouldn't worry about it.

Don

99silveradoz71 · January 12, 2009

My 99 worked the same way- delayed shifts when cold until warmed up.

irengineer · January 12, 2009

I have a '99 Silverado Z71, 5.3L AT, and it seems that in the winter, when the truck is cold, the shifting pattern is different. It will shift into 2nd ok, but it will rev out pretty far for 3rd. It seems that it only does it when real cold and doesn't do it when the truck is warmed up. Are these trucks set up for the transmission shift pattern to assist in warming up the motor quicker. I know of some Fords that are set up that way. I talked to my local tranny shop and he wants me to drop it off for him to take it for a test drive sometime. Oh, this is my 3rd winter with the truck and it has done it ever since I got it during the winter. During the summer it is normal.

Thanks

Lee,

It absolutely is designed to operate in this manor. Your description is on the money and I wouldn't feel a need to any further diagnosis.

IRE

seadoons · January 12, 2009

One more response to make you feel better - my 2002 does the same thing. When it is really cold it will delay the shift points until it has warmed up.

Frank S · January 13, 2009

Not meaning to intrude or go off topic here guys but can anyone explain to me why someone named "BEEF" reported this post to the staff with "faefadfadflhadlfjadlfjal;dfkuaweporfjnal;dfadfadf" as the reason for reporting it?

BuckFeverZ · January 13, 2009

Not meaning to intrude or go off topic here guys but can anyone explain to me why someone named "BEEF" reported this post to the staff with "faefadfadflhadlfjadlfjal;dfkuaweporfjnal;dfadfadf" as the reason for reporting it?

I thought it was obvious :dunno

txab · January 13, 2009

Not meaning to intrude or go off topic here guys but can anyone explain to me why someone named "BEEF" reported this post to the staff with "faefadfadflhadlfjadlfjal;dfkuaweporfjnal;dfadfadf" as the reason for reporting it?

Lack of English skills?