What is the blue plug?

[pocobill7t1]

[pocobill7t1]

It is a blue type of plug that is on the drivers side on a turbo 350, just near where the shift linkage connects to transmission.

[monte70car]

Bill did the transmission come out of your car or out of another car? I remember someone on here a few years back as running a 350 that had the option to lock up the convertor so that could be the case here.

[Mo's70MCs]

Sounds like you're describing the vent plug. I can't see the attached picture clearly. Is it an electrical plug? Probably a th350c with lock-up converter?

[pocobill7t1]

The picture is not my tranny, but the blue plug / connection is the same as in my car.. The trans came in the car when I bought it a couple of years ago. I have a feeling this must be a new transmission 1978 +.

Sorry for the bad pic I will get an actual one later on. It looks like a electrical connection but unable to get a good look as it is hard to see in the car. Will try to get a mirror to see what's on top of it. Thanks guys

[pocobill7t1]

_{lets try this picture.}

[pocobill7t1]

try again

[mrj52]

Turbo 250C from 79 thru 84 and turbo 350C from 79 thru 84 used this plug for the TCC control wiring. Its used for convertor lock-up and the computer electrical-mechanical control system.

[pocobill7t1]

Turbo 250C from 79 thru 84 and turbo 350C from 79 thru 84 used this plug for the TCC control wiring. Its used for convertor lock-up and the computer electrical-mechanical control system.

OK so I don't have anything hooked up to this? Advantages or disadvantages .

[pocobill7t1]

[pocobill7t1]

"

[mrj52]

Not using the lock-up function will not hurt the transmission BUT why not hook it up to utilize the lock-up feature at cruise. B&M makes a wiring kit for this. "NOTE" Lock-up and non lock-up toque converters are not interchangeable, must use the torque converter for the style trans

[pocobill7t1]

Is there a way to figure out what converter is in there or does it have to be takin out?

Does locking up the converter really help and is it worth it. New to this.

[mrj52]

You have to take off the torque converter. A non lock-up converter will not fit all the way on to the input spline There is a extension to the input shaft that has a "O" ring on the end. Locking up the converter gives about 1 to 3 MPG's. Tranny runs cooler a bit as well.

[pocobill7t1]

Just to up date, this plug is for a lock up converter. Don't be afraid to pull this out as I found out it has a replaceable O ring. Replaced the o ring and no more leaks.

[Bernie D]

The blue plug on the driver side above the pan is leaking from my 350 transmission. It has to wires going from the blue plug to inside the transmission as I dropped the pan. I can’t get it to just pop out. On the top of the blue plug there are no tabs that you can press to either push it out or in. I cleaned everything and used some permatex transmission sealant. I have a few pictures. I asked a mechanic he believes the valve body might have to come out. Any ideas I would appreciate it. This transmission is in my 1980 Chevy c10 2wd

[jft69z]

Welcome Bernie!

Note: I emailed a few links to Bernie related to the plug (looks like it's a T350C, with lockup converter), but if anyone has experience removing that particular plug, please share. The few things I found suggest there's a couple tabs on the backside to squeeze, and an o-ring in there. Popular opinion was to replace the connector with new, since you're already there.

[FrankOC]

hah!  never new there was a 350 with a lock up converter.  

[420ponies]

This was just before the TH2004r overdrive.

[Scott S.]

One of G.M.'s many experiments..... 

P.S., the easiest way to I.D. a "lock up" torque (my transmission guy told me) is that the front of the torque is flat. Like a sauce pan.

The back half is more rounded, like a bunt cake pan. 

O.K.... So I do a like baking......