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Chevy Silverado and GMC Sierra Transmission Problems



  • obyoneobyone Posts: 8,065
    You have the 4L-60E. I'd check around and see if you can fit a 6L-60E before looking at a 4L-80E. Just my opinion.
  • hi, if you thought the trans fluid was oil that indicates to me that it is burnt, when a clutch pack burns out it will cook the oil. 35 mph is the usual shift point for 2nd to 3rd at mid throttle, what you can try is to push it to 40 to 45 mph at heavy throttle then let all the way off and see if it shifts into 4th gear that will let you know if you have a pack burnt out. as for being 1 qt low that should not affect the operation there is a built in cushion, even so it is still a good idea to keep the fluid levels in their operating ranges as indicated on the dip sticks. the year and engine displacement would help even further.
  • The 4L60-E is what you have. The 4L80-E will not fit your transfer case,Bolt pattern is different and the 4L80-E has a larger output shaft. It would be easier to build your 4L60-E with heavier upgraded parts to make it beefier. "Good Luck"
  • My 2008 Z71 4wd with 28000 mi tries to shift from 5 to OD at 1200 to 1400 or so but cant seem to make up its mind and goes back and forth from 5 to 6.. Problem started at 26000mi The result is a chug at that rpm range and 40mph. It happens at light throttle. with a load it doesnt do this. Drivability is not a particular problem just annoying. I have had the transmission taken down and checked. no problems found. The conclusion is that the software says shift to 6 to save gas and for better mileage.? Maybe related to 10% ethanol gas? No software change is available says dealer.
  • i have the same issue with my 2010 sierra 2wd. took 1 truck back because of this.
    now with 4800 miles this one is doing it.
    dealer says there is no problem. BS! unfortunately it is intermittent and hard to diagnose but, it definitely is not right. anybody heard of any solutions to this issue?
  • I've got a 6.5 turbo diesel, type "s"; Ext cab; 2wD.

    Got in one morning and no reverse.

    Fluid was burnt.

    Changed fluid and seal -still no reverse -nothing at all!

    All other gears work perfectly.

    I'm told the reverse band is fried, I'm hoping someone gives me a much cheaper solution.

    If it is dead and I need to get a used one, I'm told by the local dealership that ONLY trannys from this list (no exceptions) will fit in my truck:
    -Ext. Cab
    -6.5 Diesel (maybe a different sized diesel, I'm not certain on that)

    From what I understand, it can't come from a suburban, van, or anything other than from above list.

    Can someone confirm this for me?

    Also, I know this is wishful thinking, is there anything in the steering wheel/column that electronically controls reverse. There's something loose, sounds like it's coming from the steering wheel itself, that's rolling around and klunking everytime I turn the wheel.
  • i am having the same problem shifting where is the solenoid they replaced located in the trans or what?
  • gmcustsvcgmcustsvc Posts: 4,001
    Hello Lstrip,
    What problems are you experiencing with your vehicle? How long has the concerns been present? How often do the problems occur? Thank you,
    Mariah GM Customer Service
  • Hi....I began having problems with my automatic transmission in my 1999 GMC Sierra, hitting 25-30 mph and it would not shift....letting the rpm's drop down to under 2 it would sometimes catch...checked the fluid and it was way over...drained it and at first it was fine..that was until I got the engine's temp up..rechecked the fluid level and once again it was way too high. I have read that the radiator has a cooling section for the tranny I figure that there is something going on in there....what is the best test method or fix for this problem? Thanks for any suggestions.
  • So my prndl display went out on my 2003 GMC Sierra 2500 and I thought it was a fuse or a light bulb but the more I search I keep finding information that links it to the transmission!?!?! It's been like this a few months and my tranny is there somewhere I could start with having to pay $125 diagnostic charge?
  • 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?
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