4L60E P0751 Not the solenoid....Help????

98 Silverado started getting the Solenoid A stuck or performance code. Shifts out of 1st at 25-30, also seems not to stay on OD. I replaced both solenoids for 1-2 and 2-3. No help. No parts in the pan, clean for 25K miles since filter change. I did notice when I removed the solenoid closest to the rear of the tranny, a spring loaded plunger popped halfway out. The front solenoid did not. I am guessing this is due to the fact it was in park and valve body was shutting off flow to one or the other solenoid?? Any ideas, local shop wants around 1500 to rebuild it.

If scanned wit the full trans scanner, shifts can be commanded, solenoid operation can be confirmed, slippage and gear error noted, this is the way diagnose any problem like this, also make sure the main connector on the trans is clean and tight. This "plunger" that popped is probably the shift valve, I assume you got in back in right?

I think the plunger is the TCC solenoid which can explain why it won't stay in OD. Not sure if it is related to the P0751 or not. Does it look like this? http://www.transmissionspecialty.com/parts/parts/77942-01K.htm (this is just the snout)

//2000CAYukon

Yes, I never fully removed the valve plunger and it is in there.
It is not the tcc solenoid, it is on the other side of the tranny I think. These 2 I changed are next to each other.
Thanks for the replies so far.

Yes, I never fully removed the valve plunger and it is in there.
It is not the tcc solenoid, it is on the other side of the tranny I think. These 2 I changed are next to each other.
Thanks for the replies so far.

Sorry, I misread your post. Yes the the TCC solenoid is on the other side. I did find this on another forum http://forums.automotive.com/community/70/4485/maintenance-repair/transmission/4l60e-shifting-problems/

//2000CAYukon

Here is another post that points at the 2-4 band as the issue http://www.transbuilder.com/tour/4L60E.html#bcc:17111

//2000CAYukon

the 2 you changed where the shift sol. A & B the TCC sol. is up front held in with 2 10mm bolts you have the change the whole harness to repalce it. there is a spring behind the one that popped out