98 Silverado Shift Issues - Stuck in 3rd

I recently changed the transmission (4L60E) in my Z71 after burning out the 3-4 clutch. Now, the truck starts off in 3rd gear from a dead stop unless I manually shift it into 1st or 2nd. I haven't gone fast enough with it to know if OD is working or not. I'm assuming I missed something but have no idea where to look. If anyone can offer some insight I would greatly appreciate it.

Thanks,

Darrin

I recently changed the transmission (4L60E) in my Z71 after burning out the 3-4 clutch. Now, the truck starts off in 3rd gear from a dead stop unless I manually shift it into 1st or 2nd. I haven't gone fast enough with it to know if OD is working or not. I'm assuming I missed something but have no idea where to look. If anyone can offer some insight I would greatly appreciate it.

Thanks,

Darrin

It may be in fail safe mode.

You will need a transmission/engine capable scanner to get codes and test it out and clear codes and drive it to see if it works OK and get any codes that comes back.
Post back any codes that you have now and if any come back after code clear.

Also check both sides of all power feed fuses to transmisson computer.
Let us know how it goes.

I agree with MT here - sounds like 'fail safe mode'. I'd like to throw something in from personal experience - there are two solenoids on the valve body at the back, side by side, right at the pan rail and it is real easy to knock one of the leads off to one. If this happens, you'll get a check engine light and it will start in 3rd. Just some food for thought.

Thanks for the responses.

I got 7 codes although some are duplicates and I got the same codes both before and after clearing the computer.
P0740
P0785
P1860
P0740
P0785
P1810
P1860
I also have some more info on the symptoms. I can manually shift between 1st and 3rd gears but neither 2nd nor 4th will engage. If I select 2nd or 4th the truck remains in whatever gear it was in last.

Darrin

Thanks for the responses.

I got 7 codes although some are duplicates and I got the same codes both before and after clearing the computer.
P0740
P0785
P1860
P0740
P0785
P1810
P1860
I also have some more info on the symptoms. I can manually shift between 1st and 3rd gears but neither 2nd nor 4th will engage. If I select 2nd or 4th the truck remains in whatever gear it was in last.

Darrin

Codes should be cleared and see what comes back first.
The codes you have lock transmission in 2 gear fail safe mode.
You have a wiring or ground or power feed problem with them codes.

With a code 740 and also 785 and 1860
The first step is to check the ign feed fuse and wiring to TCC wiring and TCC solenoid.

Code 785 with other codes check the ign feed fuse and wiring circuit to 3-2 shift solenoid.

Same thing on 1860 code with code 740 and 785 check wiring and fuse feed circuit.

Also not condition of transmission wiring plug-in.

Code 1810 deals with transmission fluid pressure switches.

Check all wiring and 12 volt feed to it for that code.

Thanks for all your help. I figured it out. The 20-pin plug had pushed into the tranny a little and hadn't locked on. I assume there were some pins not making contact. Once I got the plug locked in place and cleared the codes the tranny shifted fine and none of the codes have returned so far.

You are welcome and thanks for posting back how it went and the fix.
Good Luck

I'm having the same problem w/ the same codes but my truck drives fine until the tranny warms up and then it happens.I've also noticed the tach and drive indicator light stops working not sure if they have something in common.

I have a '96 Z71 with the same exact problem, goes straight to 3rd gear and stays there, have to manually shift but even then I only get 2nd and 3rd. Reverse works fine, but nearly every time it acts up the gauges die on me, too. Just started happening yesterday. Only happens at operating temp, and even then not all the time. Definitely some sort of electrical prob, but can't get under the truck now and test all the connections, much less access the many solenoids and actuators out of reach. Anyone have this issue before and discover some sort of chronic fix for it?

I have a '96 Z71 with the same exact problem, goes straight to 3rd gear and stays there, have to manually shift but even then I only get 2nd and 3rd. Reverse works fine, but nearly every time it acts up the gauges die on me, too. Just started happening yesterday. Only happens at operating temp, and even then not all the time. Definitely some sort of electrical prob, but can't get under the truck now and test all the connections, much less access the many solenoids and actuators out of reach. Anyone have this issue before and discover some sort of chronic fix for it?
Welcome to AF
With your own problem.
Best to start a new thread with it.
Saves on hijacking fees.
It is hard to match other peoples problem with yours.

The only way to test check computer controlled transmission shifting problems is with a transmission/engine capable scanner.

Get it on a good transmission scanner and check transmission data and for transmission/engine codes.
Post Back codes with a new thread .

Usually no shifting and no tach indicates a problem with the ignition switch, check for power at the trans fuse when the problem occurs