Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Silverado and GMC Sierra Transmission Problems



  • catamcatam Posts: 331
    Most likely it's the NSBU switch. (Neutral Safety Back up).
    Its an electrical switch mounted on the drivers side of your tranny. In earlier Allison trannys it was poorly shielded from the elements and prone to failure. I'd start there.
  • Hi im new to this forum. I have a 2005 GMC Sierra. the transfer case slips into neutral when taking off from a stop sign or when throttling in to it. the transmission was replaced about 2 years ago. i was thinking the encoder motor? what do you guys think.
  • smg78smg78 Posts: 1
    I am looking to buy a good condition input gear for my 261xhd, why used? its simple cause I’m broke. But not having one keeps me from fixing my truck, not having my truck keeps me from making money, No money means I cant pay retail prices and the circle keeps going. If you have one that’s new or dealer or whatnot feel free to email, but my preference is used.

    If you have one let me know price, your location and if you accept paypal or how you would like paid. I live in Maryland(20832) my email is
  • I just bought a 2001 chevy 2500hd 4x4 with the 6.0 and auto trans. most of the time it ran at about 100 - 110 temp then it hit 210 and blew the external cooler out. I replaced the cooler and added the new dex 6 fluid to refill it. it ran at about 50 deg running 70 in 60 deg temp after that and for the last week, today while pulling into the drive the motor stalled out several times and the trans temp hit right at 200 deg, any ideas? It also shifts hard into 1st but shifts fin after that.

    I unhooked the egr valve elect. when it begain to act up to see if it would change the running of the truck, it didnt. after the truck sat turned off for a min i re started it and it ran fine. but the trans temp stayed up around 200.

    Anyone have any isdea or help?
  • chevy did redesign those hoses, and they still leak. there is a really great fix available at
  • jonmic1jonmic1 Posts: 1
    My problem is with my 2001 Silverado. I've had it for about 6 months and recentley it has been hard to shift (auto) from 1st to 2nd. Not all the time just somtimes. Also while driving my power seat starts moving, until I hit the control. And lastly sometimes i get in the truck and I notice the time on my dashboard has changed, but not the presets. Otherwise it has been a great truck. It was previously used as a 5th wheel. Any thoughts would be appreciated
  • Hi,

    I parked my truck for 2 weeks and come back home. When i started it up and put the trans in overdrive it don't want to shift right. It takes it awhile to shift from first to second and takes awhile to pickup speed. When u let off the gas it shifts fine, but if u get on it, with the pedal mashed down it wont shift right. ANY HELP WOULD BE APPRECIATED.

  • I need to install a trans cooler for towing approx 4000lb trailer for now, anybody have some pics on the install???
  • Forgot to mention 2001 Silverado 1500 4.8L
  • Hello everyone I have a 2000 GMC sierra 1500 5.3 lt that backfires and misses while going down the road at low RPMs when it is high Rpms it cleans out or runs better changed maf sensor and didn't seem to help runs better with it unplugged has anyone else had this problem? I have thought of everything and can't seem to figure out what it might be. Thanks!
  • I have a 2000 1500 sierra 5.3 3.73 gears, with a cat back exhaust, throttle boby spacer, and a cold air intake system. I' m thinking of adding a programmer for more power when towing. I tow a 31 foot travel trailer weighing about 7500 lbs loaded. I'm looking for input for the best programmer, for the most power. Thanks, Marc
  • mike480mike480 Posts: 2
    I have a 99 Chevy 2500 4wd, that locked up today, but not in reverse. I backed out of my driveway and when I shifted into drive, it would not move. You could tell it was the front diferential that was stopping it from moving. I tried several times going into reverse and forward and it would not budge. I assumed it was screwed. I called a tow truck and we had they had to drag it onto the bed, with some type of sliders they put under the front tires. About 3/4 of the way up the truck, a loud bang happened and one of the front tires started to turn. Ok, got to the shop and unloaded it, Checked to see if it would move forward, and it then worked fine. Any suggestions?
  • obyoneobyone Posts: 8,065
    Which trans cooler is that? Factory? Aftermarket? Checker's special?
  • I am looking for a good quality trans cooler, trans shop said an LPD style that is good for the winter--any suggestions???? There are so many to pic from on EBay. Would I be best to get an OEM trans cooler from the dealer that includes the lines etc. What part number would I get??? The OEM style I saw on EBay looks like you just hook up directly to the trans and then to the cooler--does this mean you are to plug of the ports at the RAD and just use the Trans Cooler only as a means of cooling?? I have a 2001 Silverado 1500 4x4 4.8L--does not have the towing package--it's a base model.
    This is the info I saw on EBay:

    2000-2007 Chevy Silverado 1500 Transmission Cooler
    Genuine GM Part Number: 12497071

    Recommended for trailer towing upgrade w/ 4.3L (LU3, L35), 4.8L (LRV), 5.3L (L59) and 5.7L (LM7) engines. Helps prevent transmission overheating.
  • obyoneobyone Posts: 8,065
    I ran that part no. at The small radiator is installed in front of the factory radiator. It plugs into the return line from the radiator. It's a simple install once you see the directions that come with that unit. BTW, I'd order it using that part no. as it is OEM and should plug and play with no problems.
  • If you notice when you look at the lines that come with it, they look pretty long as if they are meant to go to the Trans itself???
  • obyoneobyone Posts: 8,065
    edited April 2010
    The lines aren't that long. If it's to scale with the trans cooler the lines won't be more than a couple of feet as they connect near the radiator to the "out" line from the radiator that returns the fluid back to the trans. The hardest part of the install will be to strap the cooler to the front side of the truck in front of the radiator. Shouldn't take more than 45 minutes to install.
Sign In or Register to comment.