2005 Trailblazer Transmission

The 2005 Chevrolet Trailblazer is the 4’th model year for this SUV.  Like the 02-04 Trailblazer’s that came before it, the 05 model comes equipped with the 4L60E transmission regardless of which engine it was equipped with.  Though, there are some unique changes to the 4l60E to accommodate the I6 motor these trucks came with.


2005 Trailblazer Transmission

Transmission Compatibility Issues for the Inline 6 Engine

The 2005 Chevy Trailblazer came with a few different types of engines.  Most of the came with the LL8 inline six engine, or the LH6 5.3L V8.  The LH6 was an aluminum blocked version of the common iron block LM7 engine that was common in the Silverado/Sierra twins at the time.

The LL8 engine used  a different bellhousing than the V8 model.    Be aware of this if you are looking for one in the salvage yard.  Or at least make sure you switch your bellhousing out so that it’ll bolt up right.


2005 Trailblazer Transmission Identification

For the entire run of the Chevrolet Trailblazer it came exclusively with the 4L60E.  The exception to this would be the Trailblazer SS, which was equipped with the performance oriented 4L70E.  The SS would not be available until the 2006 model year, so it needn’t concern you i you are looking to ID a 2005 Transmission.

20050Trailblazer Transmission
You can see the RPO code M30 clearly in this picture. This is proof positive that this vehicle is equipped with a 4L60E

The easiest way to determine what kind of transmission is in any GM vehicle is to use the RPO codes.  RPO codes are a series of unique identifiers that GM uses to show what kind of options were installed in each particular vehicle.  The RPO code for the 4L60E is M30.  It is usually stamped on the case itself.

As long as the transmission is still in the car in question, you can just take a look inside the glove compartment.  There’s a handy list of all the important RPO codes right there.  Once you see the M30 code, it’s proof positive that the transmission that came in the vehicle is a 4L60E.  If you are trying to figure out exactly what make and model that a 4L60E came out of, it is possible.  For more on that check out 4L60E identification.


2005 Trailblazer Transmission Problems.

There aren’t a lot of Trailblazer specific problems for the 4L60E.  We’ll try and cover the common issues with the 4L60E for this model year and touch on any know problems with the 2005 Trailblazer Transmission.

The section below is presented in a troubleshooting fashion to help you assuming that you are having problems right now.  If you don’t see what you are looking for you may wish to go ahead and take a look at the page 4L60E Transmission Problems.  It is more technical and in depth than what is presented below.


Won’t Go into Gear

If your 2005 Trailblazer won’t go into gear, there’s a good chance that the safety switch that keeps the linkage from engaging has gone bad.  What happens is that the vehicle no longer detects that you have applied the brake before you shift.  Alternatively, the linkage may very well be stuck.  This is significantly less likely than the first situation.

If you believe this may be the problem with your trailblazer you should check out:  Automatic Transmission Won’t Go in Gear- Troubleshooting

Only One Forward Gear And Reverse

With the 4L60E that is equipped with the 2005 Trailblazer, it’ll do this when it believes that there is a potentially fatal problem.  It then activates “limp mode” to keep you from getting stranded and potentially saving the transmission from more costly repairs until a professional can take a look at it.  For more on limp mode check out:  Limp Mode Causes and Solutions


Slipping is a serious problem and can cover a number of transmission issues.  Typically it’s going to be low transmission fluid or the transmission beginning to fail.  Now matter how well maintained, at a certain point there’s going to come a time when the 4L60E is going to need rebuilt.  Automatic transmissions are complex machines and break down like anything else.  You should check the transmission fluid and then take it in to a shop for a professional to take a look at it.  Here’s way more on slipping transmissions:  Transmission Slipping Diagnosis


2005 Trailblazer Transmission Rebuild Cost

Rebuilding a transmission is probably more difficult than rebuilding a motor.  If you think you can handle it, rebuilding a Trailblazer’s 4L60E will only cost a couple hundred bucks.  If you take it to a mechanic, a good price to expect to pay would be somewhere around $2000 for the whole thing.  This is going to fluctuate depending on what region of the country that you live in thought.

For more info check out:  4L60E Rebuild Kit4L60E Rebuild Cost


Wrapping Up

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