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Chevy Silverado and GMC Sierra Transmission Problems



  • 99z7199z71 Posts: 1
    My truck has over 180000 miles on it now and recently after driving for a while the transmission shifts real hard from 1 to 2 and to 3. It shifts fine when cool or ran less than 2 hrs. Can anyone tell me what may be going on.
  • Check out Hypertech's Max Energy Programmer. You can increase mileage and power output for either regular or premium fuel, adjust rev limiters, adjust transmission shift points (RPM) and firmness, correct speedometer when changing tire sizes or axle ratio's and more. Go to for details.
  • We have a 2001 Chevy 2500HD that seems to shift hard all the time now. It has 150K miles on it. The check engine light is on.. and sees to always be on. Even when we fix whatever error message comes up. URG! Any ideas as to why it shift so hard? We would love to keep this truck forever but now we are not sure. It has been doing this since spring. It doesn't matter if we are driving on the highway or in town. It doesn't matter if the engine is hot or cold.. same thing. Our tranny sensor does not show the tranny running hot. Its still shows in the normal range. We have already tried the tranny seafoam and that did nothing.
  • gmcproblems2gmcproblems2 Posts: 1
    edited October 2010
    2007 GMC 1500 Z71,,,I've had the same problems.Currently the main issue I have is when slowing down and then accelerating, I hear a clunk sound. It sounds like a driveshaft universal joint. I also hear the same sound but not so pronounced when driving slow and the trans shifting w/o alot of torque. I,ve contacted the customer service complaint line located in the back of the owners manual. Since they refused to fix the problem, I'll make sure it's documented and I'm even going to notify the BBB as the manual suggests. It took the dealerships 5 tries to correct a defective pass door post panel. I'm not even going to mention the improperly rotated tires which caused cuffing. All they say is the problem is normal for this year and transmission. If the Pres of GM had this problem, they would fix it!
  • ricdricd Posts: 1
    Have you found a solution yet, my '01 Sierra just started the same thing.
  • rus8rus8 Posts: 1
    my truck has 130000km on it. when the automatic transmission shifts from 2 to 3rd it makes a really weird sound. Not a clunk but a noise almost like a clutches slipping or somthin
  • bmt884bmt884 Posts: 1
    I have a 2008 Sierra All-Terrain Package Z-71. Last Monday, I began to hear and feel a loud clunking noise when shifting from 2-3, normally from a stop. While this bothered me, I didn't get upset because my truck is still within the bumper to bumper warranty, and obviously also the 5/100k powertrain warranty.

    I took it to the GMC dealership. The service advisor, who has always been very helpful, immediately diagnosed the problem as the "slip yoke". He explained to me GM has been having problems with the slip yoke not being properly lubed and they would lube it for free. If the problem was not solved, they would replace the slip yoke.

    They had it for one day. They returned my vehicle to me, and as I drove away from the dealership after waiting on traffic, the loud clunk noise appeared in the shift from 2nd to 3rd. I immediately turned around and they had the mechanic ride with me. He said "yes that's a problem, and I don't know what it is, but there is something wrong. Bring it back Monday and we'll get our transmission guy to drive it."

    I returned it 2 days ago, and they called me today to pick it up. They told me they couldn't figure it out and contacted Tech Support. Bottom line, they told me GM said it was normal and there is no solution according to the bulletin. Problem is that I bought a $42,000 truck, and I don't want to live with it. And if it is so normal, why hasn't it always done this, and why don't all GMC trucks do it? I asked and received a copy of the bulletin and this is what it said:

    Document ID: 2394678
    #01-07-30-042F: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise- (Feb 5, 2010)

    Subject: Information on 2-3 Upshift or 3-2 Downshift Clunk Noise

    Models: 2010 and Prior GM Passenger Cars and Light Duty Trucks, 2010 and Prior HUMMER H2, H3, 2005-2009 Saab 9-7x with 4L60E, 4L65-E OR 4L70-E Automatic Transmission (RPOs M30, M32, M70)

    This bulletin is being revised to ad the 2010 model year and 4L70E transmission. Please discard Corporate Bulletin Number 01-07-30-042E (Section 07-Transmission/Transaxle).

    Important: For 2005 model year fullsize utilities and pickups, efer to Corporate Bulletin 05-07-30-012.

    Some vehicles may exhibit a clunk noise that can be heard on a 2-3 upshift or 3-2 downshift.

    During a 2-3 upshift, the 2-4 band is released and the 3-4 clutch is applied. The timing of this shift can cause a momentary torque reversal of the output shaft that results in a clunk noise. This same torque reversal can also occur on a 3-2 downshift when the 3-4 clutch is released and the 2-4 band applied. This condition may be worse on a 4-wheel drive vehicle due to the additional tolerances in the transfer case.

    This is a normal condition. No repairs should be attempted.

    Why not just fix the problem??? I am very upset and feel cheated because I actually switched back to GMC from a Ford that gave me zero problems.
  • Good luck! I have a 2001 2500HD that has been having this hard shifting issues since spring. No one has been able to fix it. The last guy put Tranny Seaform in... and that did NOTHING! Our tranny fluid is clear. Is yours? We were told if its not clear then you might have a serious problem.. but who knows if that is true or not (clear meaning w/o chunks in it).
  • I have a 2010 GMC Sierra Crew Cab 1500 pickup with a 6 speed transmission. The transmission has selections for Park, Reverse, Neutral, Drive and (M) M allows you to select from all 6 speeds. 6, 5, 4, 3, 2, & 1. You can use Drive only or move the gearshift into (M) that should first go to 6th gear at top so the transmission does not tear itself apart by dropping down into a much lower gear such as Low (1). Well my problem is when I select (M) it first shifts down into Low (1) which could destroy the tranny and who knows what else. Has anyone who owns the 2010 (or other years) GMC Sierra 1500 pickup had this happen?

    Help me please. CAH
  • I have a 2008 Sierra 4x4 with automatic transmission. On drive home the transmission would go into a free wheel type of activity. When I would hit a certain speed, the RPM's would keep going but the transmission would not keep up. Almost acting like truck is in neutral.
    But when back to around 20 MPH it would catch again. Did it in Drive and 3rd, eventually got down to 2nd gear and was able to limp home.

    Any ideas on why the transmission would not keep up with speed and disengage? Is whole transmission shot?
  • Check your "Heat Temp Sensor", this will cause the hesitation going into gear ! I know it sounds crazy, but the "Heat Temp Sensor" tells the computer the engine is still cold and it keeps dumping more fuel , causes hesitation on take off! Just something to check !!!
  • gmcustsvcgmcustsvc Posts: 4,251
    I would definitely recommend taking your vehicle in to be diagnosed. Please keep me updated on your progress.
    GM Customer Service
  • 89 GMC Sierra K2500-
    I was accelerating from a stop sign and suddenly lost drive in all ranges plus no 4wd. When I inspected underneath the truck I noticed that wire harness that holds the switches for the transmisson and and transfer case had somehow come loose and all of the wires got riped by the one of the drivelines. I also had a blown fuse on the 4wd fuse. Long story short, I fixed the wiring, replaced blown fuse and ended up replacing torque converter and put the transmission back in the truck. Now when I start it up (with the rear axle jacked up) the rear axle does not spin unless I rev it up. Now the weird thing is that it spins the same way in drive than it does in reverse. Do I have some wires crossed here or what? Im stumped! Any insight to this matter would be greatly appreciated. Thanks,
  • AHA !!!!!!!!!!!!!
    I have a 2003 1/2 ton extended cab that sometimes feels like it is slipping out of gear (only for about a 1/2 second at a time) The odd thing is that I noticed that when it happened, the temp gauge would drop to the coolest !!!
    I could not think why the two things would be related, but maybe that is the problem.

    Will it get worse if not addressed, and about how much would the dealer charge to fix/replace the "Heat Temp Sensor"??
    THANKS !!!
  • I actually have my 2010 GMC Sierra at the dealership now, although we have different issues with the truck it is also with the transmission and the dealer's mechanic drove it and noticed the problem. They are saying that we have a lazy transmission, the mechanic said that it has a learning transmission, but they are baffled why it does not know why it does not know when to shift.... I kind of feel in the same boat that we bought a 44,000 dollar truck and don't know what the problem is or how they can fix it. We had a 2005 Chevy Hybrid before this and had no problems until the 5 years were up. Then the big problems set in. Since it was electronic in certain areas such as steering we lost sterring going down the road and the truck was running, but we also had shifting issues with that truck as well, this is a first year for this transmission so if you find out anything before we do PLEASE let us know what your issue is, we already asked the dealer to see what the trade in value for this truck will be so that we are not getting another lemon. Good luck with your issue glad to see that we are not the only ones that are dreaming that this is happening,
  • gmcustsvcgmcustsvc Posts: 4,251
    Was the dealer about to fix your concerns? Please e-mail me and keep me updated on your situation. Thank you!
    GM Customer Service
  • last year my truck would not accelerate over 45mph, rpm's kept rising but mph would not ,two months ago did it again exact same problem...only did it for a minute or two each time, other than those two times truck has not acted up...........any ideas on what could cause this problem
  • Hey guys ! New to site need to locate speed sensor to hook up new speedometer cable . can you help me please ? old cable was unplugged before I bought it by previous owner .
  • I have a 1996 chevy 1500 pickup. I had problems with my transmission slipping in second to third gear. So I just changed the Transmission yesterday 11/18/10 with Another Transmission and Guess what, I have the SAME EXACT PROBLEM. Can anyone with knowledge about this problem PLEASE help me?
  • guitarmnguitarmn Posts: 3
    edited November 2010

    has anyone experienced a whining after shifting from 4x4 to 2x4? This has been happening since I got the truck and no one at the dealer seems to know why. We've taken out other trucks and they don't make the noise. We've had the transaxles apart and no sign of wear. It drives me nuts as it gets worse in the colder weather. If you move the 4x4 shifter back and forth just a little sometimes it will stop. It sounds like the front axles haven't fully disengaged.

    Thanks for any help
  • You most likely have the classic brake fluid leak from the bottom (at the sensor) of the brake fluid reservoir

    The fluid leaks down into the wiring that impacts the CC and other electronics.
  • This is a brand new truck, no leaks just one really irritating noise. I've hit a wall with the dealership as they can't find anything wrong. They can hear it, they can go out with me and we can make it happen and then like I said you move the 4x4 shifter just a bit back and forth and it's gone. Till the truck sits and then its back again.
  • I too have a 2000 Sierra 4x4 that did exactly the same thing. It seems Sierra problems are the same across the board. I also have the same problem as someone else noted about when the tranny gets heated up, approx. 100 miles, the upshifts hit very hard. I now have 208,000 and something that just started the other day; when I accelerated to pass someone, the rpm's went soaring up, but the truck wouldn't do a thing. I'm suspecting the tranny is shot unless someone tells me otherwise. Thought about upgrading to a newer GMC, but the problem blogs scare me. Maybe I should just keep replacing parts. It's still cheaper than a new truck payment. Be prepared!
  • It could be forward clutch piston, also check and make sure you are not leaking brake fluid from the master brake cyl. on to the wiring , if so you will need to repair the brake cyl. and use electrical cleaner to clean off the brake fluid !!!
  • gmcustsvcgmcustsvc Posts: 4,251
    Can you please e-mail me with your VIN, current mileage, involved dealer, and complete contact information including a good number to reach you at? Please also include a summary of your situation including how many times you have been to the dealer. I look forward to hearing from you!
    GM Customer Service
  • Check to make sure your truck is not leaking brake fluid onto the wiring below your master brake cyl. ! Might be causing problems with the CC !!! Good Luck !
  • It's not a rare truck at all, the 5 speed nv4500 was offered in all GM 3/4 and full tons from 04-07(classic). And in all GM full tons from 92-02.

    As well as the same transmission being offered in a number of dodge pickups
  • Could be a fractured SUNSHELL ,or the splines are sheared off !
    Don't drive or you could do more damage to transmission ! Just something to look at ! GoodLuck
  • When you apply the brakes it sounds like the converter unlocks,verify line pressure!
    Torque Converter Control hydraulic circuit could be worn. You might need to replace the Torque Converter !
  • I have a 2010 2x4 1500. 6cyl. Have noticed when slowing and the vehicle approaches a shift point it bucks.Also, when vehicle is almost at an upshift point at a slower speed I hear a vibration in the rear half of the vehicle. anyone have those kind of issues?

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