transmission not shifting into 3 rd or 4th [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: transmission not shifting into 3 rd or 4th


dfduncan02tb
01-08-2011, 09:20 PM
I have a 2002 trailblazer. The transmission seems to be fine in 1st and 2nd, but won't shift into 3rd or 4th. Today, we pulled the pan and changed the filter. The filter was pretty clogged, but there wasn't any metal in the pan, and the fluid wasn't burned. We also looked at the torque converter through the inspection port, and everything was clean. We are stumped. Any help would be good.

efi-diy
01-09-2011, 12:59 AM
How good are you with transmissions? I could give you advise but need to know your skill level.

christo829
01-09-2011, 09:44 AM
If you've got no warning lights on the dash, you may have a stuck valve/solenoid in the
control body for the transmission. Some of those can get gummed up if there's debris
in the system. From the sound of it, that's a strong possibility, and you can have a valve
get stuck and not generate a failure code.

If you *do* have a "Reduced Engine Power" or SES light on, there are conditions that will
cause the PCM to not allow the transmission to shift beyond 2nd, and you'll need to find out
what is causing that.

How many miles, and how's the maintenance record?

Good Luck!

Chris

dfduncan02tb
01-09-2011, 10:04 AM
I'm not very good with transmissions, but I'm good at figuring things out and at following directions. The trailblazer has around 130,000 mi, and the transmission was rebuilt less than 2 years ago at 110,000 mi. Could one of the shift solenoids need replaced? Also, when you put the shifter in "3", it's the same as when it's in neutral. The rest are fine. Seems plenty strong in reverse, 1st, and 2nd. Thanks for any help you can give.

dfduncan02tb
01-09-2011, 10:06 AM
Also, no codes or lights on the dash.

christo829
01-09-2011, 10:20 AM
Did you have any sort of warranty on that rebuild?

Sure sounds like a stuck valve. When you move the shifter in the D-3-2-1 ranges, you're not
actually putting the transmission in that gear as much as you're "allowing" it to reach that
gear in the normal process of upshifting or downshifting.

The fluid not being burnt is good, as it would tend to indicate that the higher gear
pack is not slipping, just never getting put in to play.

None of this is 100% guaranteed, but it does seem like it's a problem in the
control body. There are some articles in the Transmission Mods area that might give
you a better idea what's involved, and plenty of members who have upgraded
their transmissions, so they ought to be able to help.

If there was that much debris after a rebuild and only 20K, I'd be a bit suspicious of the
quality of the rebuild, but that depends on just how much they rebuilt. I suspect that that
debris is what caused the failure, but it could be that they never replaced some of the
valves/solenoids, and it carried over a problem from the original build of the transmission.

Cheers-

Chris

dfduncan02tb
01-09-2011, 10:02 PM
So am I looking at needing to have my tranny rebuilt? I looked at my paperwork from the last rebuild and the warranty was for 6 months. Not going back to that shop. Salt Lake City, UT is only an hour and a half away, so I may trailer it down there to get it fixed. If anyone knows of a good shop there, let me know.

efi-diy
01-09-2011, 10:38 PM
Consider getting a GM rebuild and do the install.

dfduncan02tb
01-09-2011, 10:55 PM
I'm hoping to save some money on this, and I found a shop in Salt Lake City that will rebuild it for me for an hourly rate plus parts. I'm thinking that there's not very much of the tranny that needs rebuilt, so that may be fairly inexpensive. As for pulling it out and putting it back in, I'm not sure how involved it's going to be. I read one post that gave a step by step on how to do it, and it said that the catalytic converter needs to be removed, and I'm not sure I have the tools to do that. Is it as difficult as it seems to be?

johnnys50stang
01-11-2011, 08:15 PM
just got my 02 trailblazer back 187000 miles rebuilt tranny hopefully make another 187000

bigpimpin571
06-19-2011, 10:51 PM
If you've got no warning lights on the dash, you may have a stuck valve/solenoid in the
control body for the transmission. Some of those can get gummed up if there's debris
in the system. From the sound of it, that's a strong possibility, and you can have a valve
get stuck and not generate a failure code.

If you *do* have a "Reduced Engine Power" or SES light on, there are conditions that will
cause the PCM to not allow the transmission to shift beyond 2nd, and you'll need to find out
what is causing that.

How many miles, and how's the maintenance record?

Good Luck!

Chris

Hi I got an 02 trailblazer and over the weekend my wife went to a store and she start the car she puts in reverse and in drive and the cuts off. And won't start , we were able to push the car to the side but on the dash it says transmission is in reverse but it won't crank to start

christo829
06-19-2011, 10:58 PM
If the shift indicator says it's still in gear, you won't be able to start it. There's a safety
lockout so you can't accidentally start the vehicle in gear.

If you never see the shift indicator change, check your shift linkage cable. I suspect
the small connector bushing has broken. If that's OK, from your description, the
park/neutral/backup switch may be malfunctioning.

Good Luck!

Chris

VConrad607
08-11-2011, 12:51 AM
We have this same problem with the TB shifting from 1st to 2nd fine, even reverse is strong.

We had a slow leak in one of the lines from the cooler, and replaced a section of metal line with black rubber trans cooler hose. All was fine until two days later (today) I went out to drive and it wasn't shifting into ANY gears at all. No reverse, 1st, 2nd at all, and the check engine light was on. So I had someone bring me some Dexron VI and I put all 5 quarts before it finally shifted to reverse. On my way to the store one of the hoses blew and spewed trans fluid all over the road. Not sure how much I lost, but I stopped and repaired the hose. I limped over to auto parts store for more fluid. Again, I'm not sure how much I lost on the road, but I put back in another 7 quarts before it started shifting into D or R. Once back on the road it shifted from 1st to 2nd no problem, but when it came to shift into 3rd it would slip like as it was in neutral. I checked he fluid hot and in park, and it looked over filled. Could it be that I'm just still low on fluid and the dipstick is picking up residual fluid making it difficult to read? Is there any sort of overflow for the TB trans? Could it be electrical safety since the check engine light has been on? Also any word on how much these systems take for fluid? I heard it was around 11 quarts. I'm tempted to put in some more fluid, but don't want to compound the problem. Thanks for any help!

efi-diy
08-11-2011, 01:05 PM
If the hot fluid level checks good on a level surface and its slipping in 3&4 better than even chance you toasted the 3-4 clutches. If this the case - its overhaul time.

If you were in 3/4 when it puked the fluid on the road then the cluches took the hit.

Without having a ridge on the cooler line to help keep the hose clamps on they will slip off. Rubber hose is an emergency fix. Want to improve your odds.... put mutiple hose clamps on.

VConrad607
08-11-2011, 05:03 PM
I brought it in to the familys shop today to read the code which was p1870 slippage. I also sucked out about 2.5 quarts since it was indeed over filled. Took it for a drive and still slipping as it shifts to 3rd. I believe it was 3rd or 4th when the hose blew, so it's probably toast. Looks like I'll be shopping for a tranny. Thanks for the reply. I don't think changing the valve body would fix this, as I have read in other threads. Thanks again!

VConrad607
08-12-2011, 07:42 PM
Ok, this might sound like a silly question, but what's the difference between a tranny that's 4x2 and one that's 4x4? I have the selector switch on our EXT for 2WD, AWD, or 4WD Hi and Lo, would that mean it's a 4x2 or a 4x4?

efi-diy
08-12-2011, 07:49 PM
On a 4wd vehicle this switch determines which wheels get power.

4x2 - rear wheels
4x4 - all wheels

The difference between a 2wd and 4wd transmission is the 2wd has a longer output shaft and a tail shaft housing to hold the rear driveshaft.
A 4wd trans has a short output shaft and no housing as the transfer case bolts to the back of the trans.

Changing the output shafts is possible. Its about 2 hours work.