Trans troubles

[Randra]

Torqeflite lurches forward in park when sitting for over a day. Sticky bands?

 

[hammond472]

Bands aren't your issue but they will be if you drive it like that. Check the shifter input on the trans first. If it is adjusted properly I would bet your valve body is sticking. I had the same problem and the trans builder did the job five times. Turns out the valve body was bad.. In park the forward clutch pack should not be engaged. If it is truly in park and it is lurching forward the valve body is bleading off pressure and engaging the forward clutch drum. Pull the valve body and clean it. Perform an air check on the servos. Install a new filter and adjust the bands. Re install the pan and fill it with new fluid. Hope you haven't pushed it or you will fry the bands and the forward clutch drum and it will be needing a rebuild.

Before I do a trans service I throw in a quart of Trans ex for trucks. It breaks down the gum and varnish and revitalizes the seals. Check the fluid level first. You might need to drain some before you dump it in. 727s don't like to be overfilled. After you add it start your engine and let it idle. Shift through the gears slowly 15 times. This allows it to flow through all the internal passages. Shut it off and perform your trans service. This stuff is cheap, works great and is good insurance.
Hope this gets you back on the road on the cheap. Good luck. Brendan