I've got a 1994 GMC Sierra 1500 5.7L V8 4x4 with automatic transmission. I have replaced the transmission filter, fluid and the shift valves. Truck still doesn't want to change gears correctly. It go

You are going to think I am crazy! Trust me, 4 months chasing the same issue. When I was blessed by meeting a old mechanic that laughed and shook his head at me. Nevermind all of that, change the ignition module that sits just under the steering wheel. You can actually change it by removing the lower column cover. I believe the part is like 40 bucks, takes like 30 minutes to change out, and your world will go back to awesome, and absolutely no time or money spent at the transmission shop. Hope this helps many many people.

It can be issue with gears or problem with transmission and needs to be rebuilt. Also get the ****** fluid checked. If it's low, then such problems occurs.

To troubleshoot these types of issues, check the actual solved problems with these types of issues.

There are solved help links provided below: -------

Click the link below and go through the details and diagrams to troubleshoot the problem: -----
2003 Lexus RX300: Transmission Fluid Burnt Brown and not Shift to reverse?

http://whatisbyme.blogspot.in/2012/05/2003-lexus-rx300-transmission-fluid.html

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2007 Chrysler 300: Transmission Stuck in Park?

http://repairhelpcenter.blogspot.in/2012/06/2007-chrysler-300-transmission-stuck-in.html

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2000 Toyota Camry: Transmission slipping and Stuck up?

http://whatisbyme.blogspot.in/2012/05/2000-toyota-camry-transmission-slipping.html

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1996 Toyota Corolla: Transmission Shift Interlock will not Release?

http://technoanswers.blogspot.in/2012/04/1996-toyota-corolla-transmission-shift.html

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Lexus LS400: Transmission or Torque Converter?

http://technoanswers.blogspot.in/2012/04/lexus-ls400-transmission-or-torque.html

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CV AXLE stuck in Transmission?

http://technoanswers.blogspot.in/2012/04/cv-axle-stuck-in-transmission.html

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Transmission in reverse, acts like it's in neutral? http://schematicsdiagram.blogspot.in/2012/04/transmission-in-reverse-acts-like-its.html

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Delayed shift and harsh Shifting?

http://schematicsdiagram.blogspot.in/2012/04/delayed-shift-and-harsh-shifting.html

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Dodge neon wont go in reverse?

http://technoanswers.blogspot.in/2012/02/dodge-neon-wont-go-in-reverse.html

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Dodge Automatic transmission will not go into reverse?

http://technoanswers.blogspot.in/2012/02/dodge-automatic-transmission-will-not.html

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Dodge manual transmission will not go in reverse gear?

http://technoanswers.blogspot.in/2012/02/dodge-manual-transmission-will-not-go.html

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Transmission is making buzzing noise?

http://technoanswers.blogspot.in/2012/02/transmission-is-making-buzzing-noise.html

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1998 Dodge Ram: Not Shift To Reverse? http://schematicsdiagram.blogspot.in/2012/06/1998-dodge-ram-not-shift-to-reverse.html

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Transmission leak on Toyota?

http://schematicsdiagram.blogspot.in/2012/02/transmission-leak-on-toyota.html

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Automatic transmission, with no reverse?

http://howtobyme.blogspot.in/2012/02/automatic-transmission-with-no-reverse.html

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No Movement When Transmission is Shifted to Drive or Third?

http://schematicsdiagram.blogspot.in/2012/03/no-movement-when-transmission-is.html

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While going in reverse mode Fuse number 27 blows on Ford Ranger?

http://howtobyme.blogspot.in/2012/02/while-going-in-reverse-mode-fuse-number.html

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These are direct links with appropriate solutions to the specific problems of gear ****.

GEAR SHIFT ISSUES

Gear indicator Shows "3" Instead Of "D"? http://whoisbyme.blogspot.in/2012/07/gear-indicator-shows-3-instead-of-d.html --------- 2006 Chrysler 300c: Shifter Stuck in Park? http://technoanswers.blogspot.in/2012/06/2006-chrysler-300c-shifter-stuck-in.html ---------- 1998 Ford Expedition: Will not Shift Out of Park? http://schematicsdiagram.blogspot.in/2012/06/1998-ford-expedition-will-not-shift-out.html --------- Car will not move when in gear? http://repairhelpcenter.blogspot.in/2012/02/car-will-not-move-when-in-gear.html ----------- Mercedes-Benz transmission sticks in first gear? http://technoanswers.blogspot.com/2012/01/mercedes-benz-transmission-sticks-in.html ---------- Mercedes Benz not engaging in first gear? http://technoanswers.blogspot.com/2012/01/mercedes-benz-not-engaging-in-first.html ---------- Chrysler PT Cruiser only goes in First gear?

http://howtobyme.blogspot.com/2011/11/chrysler-pt-cruiser-only-goes-in-first.html

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Car is stuck in park and the shift will not move?

http://howtobyme.blogspot.com/2011/08/car-is-stuck-in-park-and-shift-will-not.html
------- 2007 Ford Expedition: How to shift car in neutral with Dead Battery http://www.howtorepairguide.com/2012/11/2007-ford-expedition-how-to-shift-car.html -------- 2002 Nissan sentra will not go out of park mode? http://technoanswers.blogspot.in/2012/02/2002-nissan-sentra-will-not-go-out-of.html -------- Nissan Sentra stuck in park? http://technoanswers.blogspot.in/2012/02/nissan-sentra-stuck-in-park.html --------- Car will not come out of Park?

http://howtobyme.blogspot.com/2011/11/car-will-not-come-out-of-park.html
----------- Automatic transmission will not go into high gear?

http://howtobyme.blogspot.com/2011/11/automatic-transmission-will-not-go-into.html

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Car won't downshift sometimes?

http://schematicsdiagram.blogspot.com/2011/12/car-wont-downshift-sometimes.html
-------- Buick Park Avenue: Transmission will Not shift into drive?

http://schematicsdiagram.blogspot.com/2011/12/buick-park-avenuetransmission-will.html
------------ No First gear Starts In Second Gear http://www.howtobyme.blogspot.com/2012/07/no-first-gear-starts-in-second-gear.html ------- Ford Taurus won't shift from park? http://schematicsdiagram.blogspot.com/2011/12/ford-taurus-wont-shift-from-park.html --------- 2006 Ford F150: Will Not Shift out Of Park? http://technoanswers.blogspot.in/2012/06/2006-ford-f150-will-not-shift-out-of.html -------- Car Transmission will not go into Park mode?

http://schematicsdiagram.blogspot.com/2011/12/car-transmission-will-no-go-into-park.html
---------- 1998 Chrysler Voyager: Transmission Problem? http://howtobyme.blogspot.in/2012/06/1998-chrysler-voyager-transmission.html ------ Shift indicator directly goes to 2nd when key is turned ON?

http://schematicsdiagram.blogspot.com/2011/12/shift-indicator-directly-goes-to-2nd.html
-------- Third gear missing and engine losing power?

http://schematicsdiagram.blogspot.com/2012/01/third-gear-missing-and-engine-losing.html
-------- Chevrolet silverado has whining sound in gear?

http://technoanswers.blogspot.com/2012/01/chevrolet-silverado-has-whining-sound.html
---------- 2002 Chevrolet Avalanche Z71: Gear shift Issue? http://whoisbyme.blogspot.in/2012/06/2002-chevrolet-avalanche-z71-gear-shift.html ---------- Hard to shift gears on Manual transmission?

http://technoanswers.blogspot.com/2012/01/hard-to-shift-gears-on-manual.html
-------- Car hard shift at slow speeds?

http://technoanswers.blogspot.com/2012/01/car-hard-shift-at-slow-speeds.html
--------- Transmission-Hard To Down Shift http://technoanswers.blogspot.in/2012/07/transmission-hard-to-down-shift.html --------- Automatic transmission shift lever hard to move on cold mornings?

http://technoanswers.blogspot.com/2012/01/automatic-transmission-shift-lever-hard.html
------------ 2000 Nissan maxima shifts hard?

http://schematicsdiagram.blogspot.in/2012/02/2000-nissan-maxima-shifts-hard.html

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Vehicle noticed sluggish delayed shifts while driving?

http://schematicsdiagram.blogspot.in/2012/03/vehicle-noticed-sluggish-delayed-shifts.html

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2007 Hyundai Santa Fe: Will not Shift out of Park Mode?

http://schematicsdiagram.blogspot.in/2012/06/2007-hyundai-santa-fe-will-not-shift.html

These details will help.

Thanks.