Talk:General Motors transmissions

There was also a TH350'''C''' version that has a lockup torque converter (TCC). The case has a "C" cast into it, and there will be an electrical plug adjacent to the shifter shaft on the driver side of the tranny, similar in appearance to the one used on a 700R4/4L60E (some early TH350Cs had a 2 prong connector while 1982-86 will have a 4 pin connector - which interchanges with the 700R4/4L60E). Not to be confused with a TH350 non-lockup tranny with a threaded electrical connector on the ''passenger'' side of the case. This is a pressure switch that was used ~1972-'73 for the Transmission Controlled Spark (TCS) system. This disabled the distributor vacuum advance in all gears except high gear, and is a single wire switch threaded into a pressure port near where the cooler lines are located. This switch may be left in place, unused- or remove it and plug the port. There have been reports of some TH350 trannys having a temperature sender in this area as well. The lockup torque converter used with the TH350C (with 30 splines, 1.703" pilot, and a 1.875" hub diameter) is similar in appearance to the one used with the 700R4 (including the pre-1998 non-LSx 4L60E)- BUT they do not interchange (700R4 incl THM200/2004R have a 1.750" hub diameter/1.703" pilot diameter).