2003 GMC Sierra 1500 - shifting problem

2003 GMC Sierra 1500, 5.3L, auto, 4wd - freshly complete and upgraded transmission and transfer case

1) last year - revving between 2nd and 3rd gear when accelerating COLD, revving when turning 90deg. corner at 20-30mph, when warm shifts perfect

2) 2 weeks ago - revved between 2nd-3rd, upshifted, then downshifted, revved to the limiter and shortly after ( 20km) lost OD, than shortly (10km) lost 3rd, transmission fluid blowing out rear vent hose

3) today - $2500 rebuilt and upgraded transmission, was rough idle when shifting between gears and even stalling, most of that is gone after several very short drives around block and transmission warmed up

Problem - transmission still revs between 2nd-3rd when cold, give it 5 minutes, shifts good, but will do it very odd time. Turn TOW MODE "on" and try it COLD, transmission shifts good

Thoughts

GM programming problem
"The automatic transmission slipped alarmingly when shifting from 2nd to 3rd and the truck seemed to lurch when accelerating moderately after making a right turn. The dealer reprogrammed the truck's computer with new codes issued on a GM Service Bulletin"

Rebuilt transmission and throttle position not relearned itself
"There is a GM bulliten that was issued for this complaint,it usually happened after a trans repair or replacement a few things can cause this problem but ill outline what the GM document says,it is up to you whether to attempt this yourself or have the dealer do it for you,ill give you the Doc number so you can present it to the dealership so they can refer to it,the GM doc number is 1351952.What may be happening is that the throttle position sensor was not relearned and causing the downshift and delayed shift to 4th"

PLEASE HELP, have no $$$ left and need this truck, last resort is to buy programmer and increase shift points to bypass this problem.

THNX in advance.

2003 GMC Sierra 1500, 5.3L, auto, 4wd - freshly complete and upgraded transmission and transfer case

1) last year - revving between 2nd and 3rd gear when accelerating COLD, revving when turning 90deg. corner at 20-30mph, when warm shifts perfect

2) 2 weeks ago - revved between 2nd-3rd, upshifted, then downshifted, revved to the limiter and shortly after ( 20km) lost OD, than shortly (10km) lost 3rd, transmission fluid blowing out rear vent hose

3) today - $2500 rebuilt and upgraded transmission, was rough idle when shifting between gears and even stalling, most of that is gone after several very short drives around block and transmission warmed up

Problem - transmission still revs between 2nd-3rd when cold, give it 5 minutes, shifts good, but will do it very odd time. Turn TOW MODE "on" and try it COLD, transmission shifts good

Thoughts

GM programming problem
"The automatic transmission slipped alarmingly when shifting from 2nd to 3rd and the truck seemed to lurch when accelerating moderately after making a right turn. The dealer reprogrammed the truck's computer with new codes issued on a GM Service Bulletin"

Rebuilt transmission and throttle position not relearned itself
"There is a GM bulliten that was issued for this complaint,it usually happened after a trans repair or replacement a few things can cause this problem but ill outline what the GM document says,it is up to you whether to attempt this yourself or have the dealer do it for you,ill give you the Doc number so you can present it to the dealership so they can refer to it,the GM doc number is 1351952.What may be happening is that the throttle position sensor was not relearned and causing the downshift and delayed shift to 4th"

PLEASE HELP, have no $$$ left and need this truck, last resort is to buy programmer and increase shift points to bypass this problem.

THNX in advance.

How many miles is on it?
Who rebuilt and installed the transmission?
Has it been checked with a good transmission and engine capable scanner?
Any codes or problems with engine running or transmission?
Have you drove it long enough for a relearn on transmission?
If you have no money left what are you going to by a reprogrammer with?:grinyes: :grinno: :lol:

How many miles is on it? Truck - 60,000, transmission now - 20

Who rebuilt and installed the transmission?
rebuild - local rebuilder I have dealt with and working with (does all local GM and other dealers) not a backyard fix-up kit
install - myself, as I own a small shop with hoist

Has it been checked with a good transmission and engine capable scanner?

Have not installed another transmission, would cost $1200 to borrow one
Scanner - no codes have came up

Any codes or problems with engine running or transmission? as above

Have you drove it long enough for a relearn on transmission? 20 not sure is enough, do not want to cause any damage, did make positive difference in feel of loading motor and stalling

If you have no money left what are you going to by a reprogrammer with? try to hit on the cutiest autoparts girl I can find :naughty:

How many miles is on it? Truck - 60,000, transmission now - 20

Who rebuilt and installed the transmission?
rebuild - local rebuilder I have dealt with and working with (does all local GM and other dealers) not a backyard fix-up kit
install - myself, as I own a small shop with hoist

Has it been checked with a good transmission and engine capable scanner?

Have not installed another transmission, would cost $1200 to borrow one
Scanner - no codes have came up

Any codes or problems with engine running or transmission? as above

Have you drove it long enough for a relearn on transmission? 20 not sure is enough, do not want to cause any damage, did make positive difference in feel of loading motor and stalling

If you have no money left what are you going to by a reprogrammer with? try to hit on the cutiest autoparts girl I can find :naughty:


Check with your re builder and see if he has any ideas.
I would suggest you get it on a good scanner and read out all transmission and engine data.
And remember a engine has to be running good for the transmission to work good.
Also check the dealer for updates on the computer.