4180E failing

[thegawd]

The first time I ever serviced a tranny I missed that metal retainer clip... **** was I pissed because the truck wouldnt move. 94 c1500 burb. Pulled it all apart and found the filter laying on the pan.... further inspection found the old clip stuck up inside.... what a relief just a newbie mistake.

Al

 

[MIHELA]

Sounds like you need to replace the harness in the trans. The early ones would leak into the connector and cause all sorts of problems.

 

[stutaeng]

Sounds like you need to replace the harness in the trans. The early ones would leak into the connector and cause all sorts of problems.

Is the '93 the early "bolt-on" wiring harness? Or the regular green connector as the later ones? I've heard the early ones had some sort of bolt on connector, but I don't know what it looks like or what years had it.

 

[MIHELA]

Not sure on the year they switched, but even the later ones can fail eventually.

 

[stutaeng]

Here's what @MIHELA is talking about. It's the internal wiring harness. You have to drop the pan. Says '91 to '03, but better do your own due diligence to make sure it's the right one, should you choose to replace it.

https://www.amazon.com/24222798-350...&keywords=4l80e+harness&qid=1607033061&sr=8-4

Good luck.

 

[CKVortec]

Are these your personal observations or just regurgitated internet babble? Because I have never personally seen a trans fail after a fluid/filter change.

I've seen it myself, before I knew what the internet was

 

[Supercharged111]

I've seen it myself, before I knew what the internet was

I say what I said having purged a few high mileage transmissions myself with zero ill effects. And when I say purge, I don't mean a weak ass filter change.

 

[Brian Leemhuis]

For sure the internal/external wiring harness. Over time and heat cycles the internal plug seals shrink and seep atf into the plug which in turn shorts your electrical system. When you turn off the truck it resets and works for shorter and shorter intervals. The replacement plug is tough to find the correct one. Mine got replaced with the wrong one and leaked like it got stabbed.

 

[Supercharged111]

For sure the internal/external wiring harness. Over time and heat cycles the internal plug seals shrink and seep atf into the plug which in turn shorts your electrical system. When you turn off the truck it resets and works for shorter and shorter intervals. The replacement plug is tough to find the correct one. Mine got replaced with the wrong one and leaked like it got stabbed.

When I did mine I potted it with silicone on the back side prior to install.

 

[stutaeng]

On a unrelated note, that harness says it has a temperature sensor. I've wondered if the ECU knows the transmission temperature, but there was just never a guage on the cluster on the GMT400s? Maybe tranny temperature is just used to adjust shift characteristics, etc.? I don't think these trucks go into limp mode if the tranny overheats, right?

But then how is a driver supposed to know what the tranny temp is? Is there a way to add a guage through the ECU? Most common thing I see is an aftermarket guage from the local parts store, which is what I've wanted to do to my '00 OBS K3500...