4L60e not shifting past 2nd gear

Trips2Florida · March 8, 2020

Ok guys, fully aware that this topic has been beat to death online but I am at this point just asking if there is a step in the flow chart that I have missed and quite frankly, if I just have a junk transmission here.

Story:

Picked up 02 Suburban, 5.3, 4L60e for $600 dollars (prolly should've been my first clue). As advertised the seller stated he had a shift solenoid problem and this was why the vehicle wouldn't shift out of 2nd gear. Test drive verified that the vehicle would go from 1-2 but nothing after that. I thought after researching the issue and how common this was and how easy the fix is let's roll the dice. I got it home and immediately went to G.M. and got two A.C. Delco shift solenoids (24230298). The the needed pan gasket/filter/fluid and complete the job. Job done and as you guessed it, no change in condition. I continued to research the issue and look to see if there were any other issues that would cause the condition. I performed them all, they were as follows:

Throttle Position Sensor

Vehicle Speed Sensor

Disconnect battery terminal

Checked all fuses

Verified no frayed wiring

Verified power at the transmission (pink wire in harness to port "E" on the plug

These are the things that I have done and there was no change in vehicle condition. The ONLY other things that I have yet to do to this vehicle we're change the ABS control module and change the PCM. But power is coming out of the PCM to the transmission. Other factors that may need to be considered:

Transmission pan was clean and not full of any significant debris besides normal.

Speedometer works while driving.

No codes generated in the OBDII

With everything that I've done I am not sure if there is anything else that I can do from a diagnostic standpoint that could point me towards any sort of answer other than I have a junk transmission. The truck has been treated very poorly by its previous owners. Dirty, rear doors don't open, etc. So for all I know someone may have drove it to the point they had mechanical failure and parked it. Anyone out there that has any ideas, I'm all ears. Just may have to source a transmission. Which is fine. But I want to verify that I am not missing something before I lay the money down.

carkhz316 · March 8, 2020

What does it too when you try to drive casually when the 2-3 shift would occur? Does it not shift, or does it seemingly rev into what feels like neutral? If the latter, your 3/4 clutch pack is most certainly burnt. The fluid was probably dark and burnt when you dropped the pan, I presume?

sefiroxx · March 8, 2020

3/4 clutches are probably shot. PO might have flushed the debris it before selling.

Trips2Florida · March 8, 2020

2 hours ago, carkhz316 said:

What does it too when you try to drive casually when the 2-3 shift would occur? Does it not shift, or does it seemingly rev into what feels like neutral? If the latter, your 3/4 clutch pack is most certainly burnt. The fluid was probably dark and burnt when you dropped the pan, I presume?

Whenever it gets to the shift point where 3rd would engage it continues to rev. That was exactly the condition of the fluid when the pan dropped. Added to that there wasn't much fluid in the pan. You can see fluid dripping out of the cooler in front of the radiator.