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hardly worth mentioning
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
66,949 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2003 Chevrolet Trailblazer EXT transmission problems

transmission problem

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2003 Chevrolet Trailblazer EXT Owner Comments (Page 1 of 2)

problem #29

Aug 302010

Trailblazer EXT

  • 122,455 miles


2003 Chevrolet Trailblazer ext, failure of transmission fluid cooling lines due to corrosion. Loss of transmission fluid and possible transmission failure due to loss. Replace all transmission cooling lines (4 sections).

- Natick, MA, USA

problem #28

Jan 052010

Trailblazer EXT

  • 65,828 miles
The contact owns a 2003 Chevrolet trailblazer. The contact stated that while driving approximately 40 mph. The vehicle completely stopped. The tachometer began to rise but the vehicle would not move forward or reverse. He took the vehicle to a repair shop and was told that the sun gear failed and the entire transmission needed to be replaced. He called the dealer and was told that they could not offer any assistance. The manufacturer was not notified. The vehicle was being repaired at the time of the complaint. The current and failure mileages were 65,828.

- Liberty, NY, USA

problem #27

Nov 022009

Trailblazer EXT

  • 92,000 miles
Transmission fluid leak caused by corrosion similar to tsb #pit-4722. Fluid seen on driveway when car parked. Fluid on undercarriage. Transmission oil coolant lines will have to be replaced at approximately $500 cost. Design issue for part to corrode after only 6 years.

- Nashua, NH, USA

problem #26

Sep 182009

Trailblazer EXT

  • 71,590 miles


While driving on a interstate at highway speed. My vehicle had a sudden decrease in forward momentum. The engine RPM's increased dramatically and the vehicle had unpredictable surges and loss of ability to maintain speed. After driving down the berm to the interstate exit, I noted a burning smell. The smell was that of transmission fluid that had leaked out from a corroded transmission cooling line.

- Waterford, PA, USA

problem #25

Aug 012009

Trailblazer EXT

  • 53,200 miles
Transmission cooling line corrosion and leak.

- New City, NY, USA

problem #24

May 012009

Trailblazer EXT

  • 63,798 miles
2003 trailblazer transmission gone bad (@63,000miles) while driving. Car stalled in the middle of the street, lucky no other car was behind.

- Cheshire , CT, USA

problem #23

Feb 112009

Trailblazer EXT

  • 82,000 miles


No warning lights, no warning sounds. While crossing an intersection, transmission went out. 0 forward gears, reverse works. Vehicle just reached 82,000 miles. Serviced regularly.

- Chesterfield, MI, USA

problem #22

Aug 102008

Trailblazer EXT

  • 95,000 miles
The transmission cooling lines corroded which caused the transmission fluid to leak out while on a 20 mile round trip from our house. The truck started to run rough as we pulled in the driveway and there it died. I had it towed to a local transmission repair shop where they confirmed the transmission was dead, rebuild or replace. I paid to tow it to the GM dealership where I bought the truck and they confirmed the tranny was dead. Aluminum cooling lines rotted out, drained the fluid and the unit fried. There are no warning lights or monitoring of this fluid level per GM. This truck had been serviced by this dealership. The service mechanic told me that this is not a common occurrence but this is not rare either. He said GM will not help with the repairs and he was right. I had the local tranney shop do the repairs for $2500, less than GM's $4500. There have been many problems with this truck, I will do another report regarding the failed door latches, and I gave GM the time to repair their problems and then they tell you to "stuff it" when their bad designs get real costly. Last GM in my driveway.

- Honeoye Falls, NY, USA

problem #21

Dec 202008

Trailblazer EXT

  • 65,471 miles
My 03 ext first transmission went out with just over 65K and then 16mo. Later at 80K went out again. No help from GM. I have owned a 99 Blazer and 02 trailblazer with no real issues however this 03 has had numerous from cracked gas tank to catalytic converter going out as well as now having loud engine noise!

- Crestview, FL, USA

problem #20

Nov 302008

Trailblazer EXT

  • 45,201 miles
I own a 2003 Chevy Trailblazer ext with 4WD. On several occasions the vehicle has rolled away while in park. Also, the vehicle on 2 separate occasions went forward when the gear select was in reverse. Finally, on 4 occasions the vehicle put itself in neutral. Twice at speed and twice while waiting at traffic lights. This vehicle nearly ran over my 3-year-old child and the dealer claims all of these instances have been driver error. I've had it with GM and their unwillingness to see any urgency with this huge safety related issue.

- Roseville, MI, USA

problem #19

Jul 142008

Trailblazer EXT

  • 51,000 miles


Driving on vacation towing camper. Tried to accelerate and nothing. Got to gas station. No trans fluid. Got it to dealership. They said trans blown due to water in trans. Dipstick rusted inhalf. Leak with hose caused problem. Got fixed GM only paid 1/2 because we fought. Had extended warranty they said manufacturer defect. Found service bulletin on internet. Still fighting to get our money back.only 51,000 miles.

- Clementon, NJ, USA

problem #18

Aug 242008

Trailblazer EXT

  • 60,000 miles
Transmission lines rotted out. Lost fluid and tranny went South!. 1400 for repairs!. thanks alot GM. Junk!

- Ashland, OH, USA

problem #17

Aug 142008

Trailblazer EXT

  • 71,000 miles
Automatic transmission fails to shift into second. Loud revving noise, failure to shift.

- Simsbury, CT, USA

problem #16

May 132008

Trailblazer EXT 6-cyl

  • 62,440 miles
2003 trailblazer transmission failure. Driving in the neighborhood (25 mph) heard a load clunk ( like something either hit or fell of the vehicle), then a high pitched whining sound, got the vehicle home (11pm). In the morning, to take the vehicle to be looked at found that I had no reverse, had to push it out of the garage. I have a extended warranty, but have given Firestone permission to replace with a rebuild unit from GM. I do not know what my warranty will cover, but believe that GM should foot the bill, since this had been a reported problem for this transmission for years.

- Charlotte, NC, USA

problem #15

Mar 242008

Trailblazer EXT 6-cyl

  • Automatic transmission
  • miles
I was driving home to Texas from a vacation to visit family in Oklahoma. All of a sudden without warning vehicle's transmission got stuck in 3rd gear. Then the transmission failed altogether. Vehicle left me stranded in the middle of nowhere with my four children. They are telling me that there are alot of problems with the trailblazer transmissions.

- El Paso, TX, USA

problem #14

Mar 212008

Trailblazer EXT 4-cyl

  • Automatic transmission
  • 44,000 miles
My Chevrolet Trailblazer ext, that I purchased 4 1/2 years ago and it has 44,000 miles on it, has a transmission problem. The Chevrolet dealership tells me that it is a 2000 fix. I am angry and disappointed that a vehicle with relatively few miles on it is having such a major problem.

- Zanesville, OH, USA

problem #13

Nov 302007

Trailblazer EXT 6-cyl

  • Automatic transmission
  • 42,000 miles
I bought a used 2003 trailblazer. I took it in because it was having issues with the engine light coming on. The engine light no longer comes on but the problem has gotten worse. The transmission slips constantly, I have only had this vehicle for 4 months. I am afraid this is going to happen when I am in the middle of traffic and my children and I will be in serious trouble.

- Pittsburgh, PA, USA

problem #12

Sep 122007

Trailblazer EXT 4WD 6-cyl

  • Automatic transmission
  • 66,000 miles
Transmission went out at 63,000 miles -- clutch fan went out along with transmission. No warning -- nothing. This seems to be a common problem with trailblazers. GM should order a recall --overall expense is over $2000

- St. Joseph, MI, USA

problem #11

Sep 122007

Trailblazer EXT 4WD 6-cyl

  • Automatic transmission
  • 71,700 miles
My 2003 Chevy trailblazer has a third brake light across the top hatch.while driving down a busy highway it was flying like a wing on the back of my vehicle luckily dot falling completely off but when I stopped it came crashing down onto my window of hatch luckily not breaking all I could do is break it completely off so it would not fly into someone's windshield behind me I work with a lady with the same make and model and hers flew right off her latch causing it to smash luckily no one was behind her. I also have it in the shop due to rusty corroded hoses that went to transmission causing all fluid to drain almost burning up my transmission no indication lights ever came on other than it skipping a little luckily a service engine light came on a week later I took it to garage and just in time. Unfortunately even with power train warranty this problem is costing me $500 out of my pocket no fault of mine wheel wells and brake drums have been beaten due to lots of rust build up and doors that were recalled and fixed three times still not working right also front headlight replaced twice in two years causing me to be pulled over twice as I did not realize the problem of my lights going out frequently.

- Carthage, NY, USA

problem #10

Jun 072007

Trailblazer EXT 6-cyl

  • Automatic transmission
  • 53,000 miles
The automobile starts out in 2nd gear and at highway speed the transmission hunts for the correct gear shifting back and forth.

- Mt Pleasant, SC, USA

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