Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 1999 GMC Sierra owners, lightly cleaned up (personal details are redacted by NHTSA).
While attempting a three point turn across a road the automatic transmission began grinding after putting the vechile in reverse. I was in the lane facing oncoming traffic when this occurred. The reverse gear no longer functioned. Fortunetly there was no oncoming traffic and I was able to put the vechile in drive and straighten it out, getting back to the parking lane. The vecile only has 49,000 miles. In the research I have done on the problem so far I have discovered that the automatic transmission failing is a common problem. For example, a man named chuck who works at all-world transmission [phone]) says these vechiles come in all the time with the same trasnmission problem. GMC claims it is a not a safety issue and will not issue a recall. I beg to differ. I had my wife and 5 month old daughter in the truck. If there had been a car coming, I might have been in trouble.
ABS system fails on panic stops. Suddenly applied pedal presseur locks brake pedal and provides little or no braking for approximately 1 second. I have been told by the dealership's service department that this is typical of all ABS and that I need to train myself not to jam the brakes in an emergency. Vehicle was in shop in dec. 1999 for transmission repair and brakes were supposed to be checked. No check was noted on repair order, but service manager assured me that the mechanic had test driven the vehicle and it was OK. This problem seems to be a result of ABS pump overreacting to suddenly applied pedal pressure and locking the pedal with back pressure before braking actually starts. I feel that the brakes should at least chirp the tires first. Currently vehicle is under repair from accident, but it will be taken to another dealership upon completion of this repair.
Dt: 1999 GMC Sierra 1500. While driving the truck for about 45 minutes to an hour and if stopping at a stop sign or red light the truck will not shift from first gear to second gear properly. Once the truck does shift it is a very hard shift, and if on wet or slippery surfaces the truck will squall the tire. This started around 60, 000 miles. This does not happen every time, it is hit or miss. While pulling across three lanes of traffic the truck shifted properly and was almost hit by on coming cars. Took vehicle to the dealership, and they said it was the transmission. It was a common problem with GMC trucks. There is a kit that is made to fix this problem, but transmission must be replaced and the repair cost is between $700 - $1,800. This happens 4 to 5 times a week.
Today while trying to park my truck, I pulled into a parking spot and was going to back up, when I heard a whirring noise. I put the truck back in neutral,noise was gone, back in reverse noise has returned. No reverse. I abandoned parking and drove home. I had all forward gears. When I returned home, I put the truck in park..... No park the truck rolled ahead and almost hit another vehicle. Called GMC, was told to take to dealer. Service manager said the problem was the reaction sun gear and shell internal in transmission. Very common problem. This is more than just a failed transmission, its a safety issue with no park in transmission. GMC basically told me I am s.o.l., and would not acknowledge the problem with no park and that safety issue.
Gas tank gauge works once in a while. Our mechanic said it was probably due to moisture. Also, the rear differential cover is either cracking or rusting through. I put a new gasket on it and the next day it was leaking again but not at the gasket. About 1/3 up from the bottom, you can see where fluid is leaking through the cover. I called 2 dealers (1 Chevrolet, 1 GMC). They both gave me numbers to other dealers (1 in pa., 1 in ia., 1 in upper mi.). The two out of state dealers told me that the part was for a customer and would not sell it. The one in mi. Also said that, in addition to "that must be a popular part, because I've had every dealer in the country call me." is this part a defective piece?
Brake fluid leaking all over bottom of truck spraying out I took to a mechanic and had 1000 dollar brake line job done got truck back and ABS brakes worked like manual brakes had a sensor and 2 ball joints replaced im being ripped of from a GMC loyal customer I was I guess back to Ford or Toyota for my next new trucks I had warranty issues you cheap [redacted] wouldnt pay for a waterpump that was leaking only a 7 dollar gasket also had a transmission on my work van repair and then replaced after a month of run around.
Went to dealership talk about techical service bulliten #86-74-03 clunk upon acceleration(replace transfer case fluid). Dealer changed transfer case fluid, but glunk noise is still there. The service bulletin states cause maybe to slip-stick condition between the rear propeller shaft slip yoke and the transfer case output shaft. The correction, drain the transfer case fluid and refill with fluid. This fluid contains a friction modifier thar should eliminate the slip-stick condtion. I feel that this service bulliten procedure did not correct the cluck problem. I said, to the technical manager that there is excess backlash between the crown-wheel and pinion in the diff. Pull it out and adjust it, as it will shorten the lfe of diff. He stated that there is no room to adjust it. I have a 1992 model that makes a clunk noise. I think my ujoints are being effected because of the backlash. …
GMC Sierra has been in shop to many times to keep track of. Truck also has a problem with sticky throttle body which has been dangerous.GMC gave extended warranty in 2000 bacause of problems also issued customer appreciation certificate if I wanted to buy new GM product.service manager told me to cut my losses and but a new one.GMC will not do a thing for me. Contacted nys attn. General about problems.GMC now has their legal core calling me at home . I have asked them to buy vehicle back research the parts and assembly to protect other owners. GMC says sorry . I asked them how they could warranty rust thru for 100,000 but could not protect ABS from corrosion, GMC response was hey you live in new york state. And they are under no financial obligation what so ever
When attempting to pass another vehicle on an incline at speeds of 55mph to 65mph the transmission shifts into second gear and revs the engine up to 4500 rpms and doesn't increase the speed because it is running at its peak speed in second gear causing me to have to let up on the accelerator and try to get back behind the vehicle I was trying to pass.this same downshifting also occurs when using the cruise control.the dealer did not want to test drive the vehicle on a similarly inclined road to duplicate the problem because he didn't have another vehicle like mine to compare it to.the defect in this transmission could easily put me in a head accident situation and needs to be addressed immediately.
Truck was drove about 300 miles at highway speed , shut off for 1 hour and drove thru town , stopped at a red light ,proceeded to take off when light turned green, engine reved up but the truck just sat there and did not move.,I verified truck was in drive snd shifted thru the gears d,3,2,1,2,3,d,n,r,p,r,n ,d engine reved but truck would not move. I turned off engine and restarted ,put it in gear engine reved then the truck started to move as if everything was normal. Truck now has 13K miles and the problem has not repeated,bet I have heard of several other 1999 & 2000 Chevy and GMC trucks with the same problem.I beleve this could be a serious defect that could cause injury to occupants or others.
Transmission complaints in other Sierra years
Frequently asked questions
How common are transmission problems on the 1999 GMC Sierra?
NHTSA has 37 complaints about the transmission & drivetrain of the 1999 GMC Sierra, 6% of the model year's 600 complaints. The component named most often is automatic transmission (19 mentions).
Is there a recall for 1999 GMC Sierra transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 1999 GMC Sierra, though it has 5 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 1999 GMC Sierra transmission problems start?
Half of the complaints with a recorded mileage happened before about 79,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 3 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.