Allison 5sp: TC or F Solenoid?

[dist3allaround]

SO I had some issues with my TC a couple weeks ago. TC would not lock up and had a P0741 code. Took truck to dealer to have a diagnostic ran on it to verify, they said it appeared to be the TC. So I removed the trans and sent the TC back east to suncoast. They checked it out and said there appears to be nothing wrong with it. I will be confirming this with them today or tomorrow.
So I then did some research that led me to the other two possibilities that could be causing my symptoms, stator sheft movement and "F" Solenoid.
I check the stator shaft and the two holes are in correct positioning at 12 and 6.
My question: What can I do to check the "F" solenoid? Do I need to wait for the TC to come back and do the solenoid check/replace with the trans in the truck? Also, I had a dealer do a trans fluid exchange service a couple months ago. They used DEX6, I used DEXIII when I installed the trans. Could this be causing any issues? Maybe something got knocked loose and gummed up the F solenoid?
Thanks for any suggestions/help anyone can give.

 

[Mike L.]

Hooking up a Tech 2 by someone that knows how to use it will pinpoint where the problem is. You can watch the command on the screen ( if there is one ) then watch the TCC slip rpm change to 0 ( if command is followed through ). You can over ride the TCM by applying TCC and see if it locks. This should be done before throwing money at the problem.

 

[dist3allaround]

Yeah, that was the reason that I had the dealer do a diagnostic. Maybe that was my first mistake.
I sent the service printout back east with the TC to Suncoast. The printout basically said, "took truck for test drive. Commanded TCC lockup, recorded several hundred RPM slip when full lockup should be present."
I expect to talk to Suncoast tomorrow. I am having them change the converter to a 1056 while it out and back there anyways. I just have not been happy with my 1058 ever since I installed it. It always seemed to be to tight right from a dead stop and has locked real hard since day one. I had the taps reset with a tech II twice since install two years ago. Unfortunately I never made it over to the Allison dealer to have them use the Allison DOC to do a full reset as you suggested a year ago Mike.

 

[dist3allaround]

OK, my TC is on its way back from Suncoast today. Nothing wrong with it. Clutches look good and everything about it checks out to them. I did have them change it to a 1056 stall. I checked the stator and it has not turned at all. The two wholes in it are still at 12 and 6.
I will have a GM tech buddy down to help me reinstall everything. I will have him bring his techII down with him so we can relearn the trans and do some diagnostics to it.
I did have a trans fluid exchange done at a dealership back in November, could I be experiencing side effect from that? They put Dex6 in rather than the Dex3 I had put in when I first installed the new trans two years ago.

 

[dist3allaround]

Can I pull the Valve Body and clean it? Any ideas on what I should check before I put this thing back in my truck and still have the same problem?