Does anyone know how the TCC is controlled on an '84 700R4? Not having an ECM, I am assuming it must be a mechanical/vacuum control. I'm trying to troubleshoot it, and the manual doesn't say a word about it.

Thanks!

 

it has a converor clutch shift valve that send torque convertor clutch oil signal to the lock up circuit at a pre determined gear ratio and vehicle speed(governor pressure)to allow lock up .other things are intertwined with this scheduling program depending on make and model

 

Like chris718 says, you should have a governor valve to control lock-up at a certain speed. You should also have the usual solenoid in the valve body, however it will be internally grounded with only a single wire to pin A on the case connector as shown below. The solenoid works with a vaccuum switch on the firewall behind the brake booster to unlock the TCC during low vaccuum.

<img src="http://www3.telus.net/~crussel/tcc_wiring_4.gif" width=100%>

If you have a Haynes or Chilton manual, it will be useless to you for this. I believe the Helm manual does mention the governor valve in the transmission section, but for complete information you'd need the Canadian service manual supplement.

 

low vacuum would be at higher RPM, youre cruising at higher RPM= higher end of a gear, doesnt make sense for it to want to unlock at low vacuum times

hmm..

 

No, low vaccuum is high demand, as in when accelerating at or near WOT.

 

Thanks all, I will try that out when I get home from work tomorrow! :hail: