1972 coupe turbo 400 issues

[Stephen B.]

Putting my engine and transmission back in my 72, I noted transmission check down switch on the transmission had a broken ear. What am I looking at to replace? Any help here would be great. Thanks

[Stephen B.]

Re: 1972 coupe turbo 400 issues

Slight mistake on my question. My 2 pin case connector has a broken blade connection. Again, what I am looking at to replace? These things are hard to fine. Thanks

[Joe L.]

Re: 1972 coupe turbo 400 issues

Slight mistake on my question. My 2 pin case connector has a broken blade connection. Again, what I am looking at to replace? These things are hard to fine. Thanks

Stephen------

When you get the description of the component you're interested in a little more accurate, you stand a much better chance of getting a response. However, I show this connector as being a single pin design, not a 2 pin (unless you're referring to the pins on each side). In any event, the original part number was GM #8629503, replaced by GM #24205373 which is also now discontinued without supersession. But, if this is what you need, they are not too hard to find. Here's one:

https://www.ebay.com/itm/TH400-SINGLE-PRONG-CASE-CONNECTOR-1965-98-GM-CHEVY-Turbo-Hydramatic-400-3L80/291218729405?hash=item43cdfd29bd:g:9n4AAOSwhh5Tndnv

[Stephen B.]

Re: 1972 coupe turbo 400 issues

John, thanks for the reply......Mine is a 2 pin looking at this on the outside of the transmission.

[Joe L.]

Re: 1972 coupe turbo 400 issues

John, thanks for the reply......Mine is a 2 pin looking at this on the outside of the transmission.

Stephen------


If it's 2 blade terminals on the outer side, then I don't know what it is or where to get one.

[Joe L.]

Re: 1972 coupe turbo 400 issues

John, thanks for the reply......Mine is a 2 pin looking at this on the outside of the transmission.

Stephen-----

I did some further checking. GM had this part cataloged in a parts group different than the one that these connectors are usually cataloged in. That "threw me off". The original part number was GM #8629502. It's discontinued but available in the aftermarket. Here's one that's one third the price of the one previously linked and probably exactly the same part. Curiously, it only took me 9 seconds to find it.

https://www.ebay.com/itm/400-3L80-TH400-3L80HD-TH475-Two-Pin-Large-Case-Connector-Oring-2-Prong-1970-82/291769299602?hash=item43eece3292:g:TYIAAOSwGeBXP3Rp

There's an important thing to understand here. The "second terminal" of this connector is for the Transmission Controlled Spark System. This is an early emissions control system that often created driveability problems. Many people eliminated this system to correct that problem. That may be why you are missing one of the terminals on your connector assuming that it's the terminal for the TCS system. Some previous owner might have done this to cleverly disable the system in an "unobtrusive" manner. By installing a new 2 terminal connector you may be unwittingly restoring the system to functionality. If you use the connector I originally mentioned, the TCS system will remain inoperative.