Hard Shifting 2-3, no-shift 3-4

[Geo99M6z]

Hi all.

Hopefully someone can shed some light on this for me instead of the dealer saying "we'll have to replace the clutches in the tranny"

1999 Tahoe (5.7L V8) 4WD is having difficulty shifting out of 2nd gear. Will finally shift at a constant rpm (2000) or at 3500 RPM or if I take my foot off the gas and then tap the gas pedal again it will shift into 3rd

Also, on the highway, it will not shift into 4th gear. If you take your foot off the gas it will go into 4th gear but as soon as you tap the gas the transmission downshifts into 3rd and will stay there until you take your foot off the gas

It started this Wednesday. It is the g/f truck, and she said that she went over a small hill in the road, kind of took it too fast and right after that it shifted into second and started the problem of not shifting from 2-3 until about 3500 rpm.

Could this be an electrical problem? Maybe a ground wire or something came loose? Where would i look?

To me it doesn't seem like a transmission problem, but an electrical problem.

Any ideas?

[Geo99M6z]

anybody with some thoughts on this?

[Mattdmann]

Originally Posted by Geo99M6z

Hi all.

Hopefully someone can shed some light on this for me instead of the dealer saying "we'll have to replace the clutches in the tranny"

1999 Tahoe (5.7L V8) 4WD is having difficulty shifting out of 2nd gear. Will finally shift at a constant rpm (2000) or at 3500 RPM or if I take my foot off the gas and then tap the gas pedal again it will shift into 3rd

Also, on the highway, it will not shift into 4th gear. If you take your foot off the gas it will go into 4th gear but as soon as you tap the gas the transmission downshifts into 3rd and will stay there until you take your foot off the gas

It started this Wednesday. It is the g/f truck, and she said that she went over a small hill in the road, kind of took it too fast and right after that it shifted into second and started the problem of not shifting from 2-3 until about 3500 rpm.

Could this be an electrical problem? Maybe a ground wire or something came loose? Where would i look?

To me it doesn't seem like a transmission problem, but an electrical problem.

Any ideas?

I had something like that happen to my 98 tahoe, My engine warning light came on; I had it checked and it was the 3-2 downshift solenoid. I replaced it, then it was fine.

[Geo99M6z]

Darn... I saw this too late.

I had two place tell me that they would have to rebuild the transmisison and it would cost me $1500.

So I bought one in AZ for $600 and will be replacing it next week.

interestingly enough the tahoe threw a code P0751 - Shift Solenoid A Performance or Stuck Off

So this is probably the only thing wrong with it.

Too late now though, the tranny is already ordered .

Thank you for the info, I wish I would have checked this board sooner.

[jackbrandon]

Originally Posted by Mattdmann

I had something like that happen to my 98 tahoe, My engine warning light came on; I had it checked and it was the 3-2 downshift solenoid. I replaced it, then it was fine.

If not this it may be the speed sensor ($99)

[99ssconv]

interestingly enough the tahoe threw a code P0751 - Shift Solenoid A Performance or Stuck Off

sounds like the stator support bearing was coming apart and binding the clutches in the input housing. the code would have set from debris sticking the solenoid. make sure you flush the cooler well after repairs to prevent repeat failures.

[Hillbilly Deluxe]

Hey guys!

I have a 99 Sierra new style with a 4L60E tranny that started doing the exact same thing .
I was tokd the tranny was done so i replaced it with 1 from the wreckers and it lasted 1 day and started doing the same. So the wreckers gave me another tranny.
This one lasted about 2 months and again same thing.
I bought another 1 thinking i have the worst luck in the world and sure enough after installing it i took the truck to the most reputable shops around.
They put it on there comp. and test drove it and said that i couldint ask for better.
The next morning i got in the truck and same thing again.

Different shops said it could be a faulty PCM,another said the MAFS could be the colperate,and another said a faulty ignition could cause this tranny problem.
So over 2 months i sank roughly 2 grand and a whole lot of time changing all the above and still the F...ing truck is still a lawn ornament.
Ive had it @ the dealership,and everywere else possible and still nothing.
So if u or anyone else may have some answers for me please!!!

And i hope ur luck may b a little better than mine.
GOOD LUCK CHARLIE!!!!

[j cAT]

with lots of ignition switch useage / high miles the ignition switch may be the problem. I would just replace the switch as a start point.

also check the fusebox fuses/sockets/wiring to from the transmission/pcm/connectors etc.

wires do get damaged on these vehicles as the protective loom covering fails with age . also sloppy repair work .abusing the wiring with non OEM routing and security.