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700r4 Torque converter lockup coming on and off

14K views 4 replies 3 participants last post by  chevy_c10  
#1 ·
Hey everybody. I have been having some issues with my 700's lockup for over a month now and have not found a fix yet. The symptom I am experiencing is the lockup engages and disengages after I have driven for about 4 miles. When the engine is cold there is no problem but once it warms up, it seems to get worse and worse until it quits all together. Just to make things clear, I have no ecm controlling lockup. I do however have it wired to lockup in 4th gear only via a pressure switch in the 4th gear pressure port. The wiring is run from an ignition 12v wire, to a fuse, to my brake switch, then down to the transmission. The things I have tried are replacing the converter and lockup solenoid. This did not fix the problem. The solenoid was starting to go bad however. Also, before anyone asks, I do have the tv cable set up properly using bowtie overdrives tv made easy system for the edelbrock 1406 carb. I am starting to get frustrated and I want to avoid throwing any more parts at it. Wish I would have waited on replacing the torque converter. :spank: So any advice I get would be greatly appreciated.
 
#2 ·
power of 12 volts loss? Loss connection , poor ground? Bad pressure switch on valve body?

You can place a check ball in the end of the lock up solenoid and re-install the solenoid.. the trans converter will lock up as the trasn shifts to 2nd gear and stay locked up till the trans drops back to first gear. There is no lock up oil provided in first gear

You can test and see if the converter starts locking in and out the clutch as the trans temp rises
 
#4 ·
Crossley, I will check the 12v supply either tonight or tomorrow. The way mine is wired, the ground side is through the pressure switch. I would like to test the continuity of the pressure switch but not too sure how to go about applying pressure once it is out. As far as the checkball idea, do you just mean as a temporary test? Not too sure I would enjoy having lockup start as soon as I hit second gear. Using more pedal to get my truck going would make the mileage even worse than what it is now.
 
#5 ·
I just wanted to post back and let everyone know I think the problem with the TCC is resolved. After doing some testing last night, I found I had power from the ignition wire up to the brake switch but nothing after that. I put in a new switch today and all seems to work as it should. For some reason it just wasn't making a good connection on the cruise control part of the switch yet it was fine on the brake side. If anything changes, I will update you guys. Thanks for the suggestion about a bad connection.