After I rebuilt my 4L60 in my '99 K1500 I originally had a Hughes TC with no lockup capability (guy at Summit steered me wrong). I ended up getting an AC Delco S-10 TC and got it installed with no issues so I was looking forward to having lockup again.
The first couple of times I drove it everything seemed to work well. Then the issues started. At first it was driving at highway speeds. The TCC would seem confused as it would lock up and then unlock. At least I assumed that's what was happening as I watched the RPMs jump between 1900-2200. It did this with increasing regularity over the next couple of days going back and forth to work when, finally, it just stopped locking up altogether. After I stopped having the TCC engage two things happened: 1) I got the P1870 code and 2) driving more than 15 miles at highway speeds would cause the transmission to seemingly overheat and go to full pressure with the 1-2 shift.
Here's where I'm at right now:
- Dropped the pan and pulled the TCC solenoid to test it. It engages and disengages just fine with 12V applied.
- The fluid looked slightly burned. Still red, but with a tinge of brown. It was also about a quart low, but I don't know where the fluid went since there are no leaks. On a side note, after the rebuild I switched to Dex VI from Dex III since everything I had read said it's a better option.
- Still have the P1870 code.
- I ordered the TCC isolator valve, but I received the wrong one (got the '00-'03 one and just waiting on @rhino to get back to me about returning it).
Questions:
- What is the likelihood that the isolator valve with fix this problem?
- What is the chance that my new (well, remanned) TC is bad already?
- If not the isolator valve or TC where else could the problem lie?
The first couple of times I drove it everything seemed to work well. Then the issues started. At first it was driving at highway speeds. The TCC would seem confused as it would lock up and then unlock. At least I assumed that's what was happening as I watched the RPMs jump between 1900-2200. It did this with increasing regularity over the next couple of days going back and forth to work when, finally, it just stopped locking up altogether. After I stopped having the TCC engage two things happened: 1) I got the P1870 code and 2) driving more than 15 miles at highway speeds would cause the transmission to seemingly overheat and go to full pressure with the 1-2 shift.
Here's where I'm at right now:
- Dropped the pan and pulled the TCC solenoid to test it. It engages and disengages just fine with 12V applied.
- The fluid looked slightly burned. Still red, but with a tinge of brown. It was also about a quart low, but I don't know where the fluid went since there are no leaks. On a side note, after the rebuild I switched to Dex VI from Dex III since everything I had read said it's a better option.
- Still have the P1870 code.
- I ordered the TCC isolator valve, but I received the wrong one (got the '00-'03 one and just waiting on @rhino to get back to me about returning it).
Questions:
- What is the likelihood that the isolator valve with fix this problem?
- What is the chance that my new (well, remanned) TC is bad already?
- If not the isolator valve or TC where else could the problem lie?
