93 Chevy trans(4l80E I think)

[searstractorfan]

What causes the trans NOT to shift into overdrive?? I was going to work and it wouldnt drop into the last gear(overdrive) but everything else worked fine...Then on my way home from work it was fine....Im gonna check the trans fluid but it pulls PERFECT no slippage just worried about hurtting OD...Also where do you install the trans temp sensor? I dont see a hole in the oil pan...

 

[ak diesel driver]

not sure on a 93 but most of the rest of the 4l80s need a temp sensor on the engine to shift into od after it gets up to temp 170*

 

[THEFERMANATOR]

No OD until the engine is up to 140, and the trans has to be up to about 90-100 as well before OD will come on. This is to protect the tranny and help the engine warm up on cold mornings. If the T-STAT goes bad or the coolant temp sensor(2 wire sensor located in the T-STAT housing) then you won't get OD either.

 

[searstractorfan]

Ah, that could be my answere...The glow plugs try and cycle like crazy when the engine is cold(below operating temp) so my T-stat housing sensor could be bad!! My OD is working fine now just didnt that morning so so far so good!!! Thanks guys, Ill keep my eye on it!!

 

[Jess_sr]

Not wanting to confuse anybody here but..
My truck only inhibits lock up when cold.
It will hit 4th/OD every time when cold.

Come to think about it my sons is the same way with his 95.

If you having a problem with your trans on a 4L80e the first thing to do is always check it for codes.

 

[BigBlueChevy]

Not wanting to confuse anybody here but..
My truck only inhibits lock up when cold.
It will hit 4th/OD every time when cold.

Come to think about it my sons is the same way with his 95.

If you having a problem with your trans on a 4L80e the first thing to do is always check it for codes.

Jesse! Glad to see you around When big blue is road worthy again I'm thinking I'm going to stop by. I think you will like what you see):h

 

[bk95td]

The 92-93 pcm doesn't have engine temp input. It uses the trans temp input to allow lock-up. A loss of throttle signal will prevent 4th gear and lock-up

 

[searstractorfan]

You guys dont by chance know where to install the trans temp gauge do ya??? Theirs no hole in the pan and I aint dropping it to drill one..Ive heard the stories of dropping pan or changing fluid and trans never works long after...

 

[NVW]

There"s a 1/8" npt plug on the drivers side somewhere up by the linkages I think. It's a real bugger to find or feel. Feel is all you can do as you can't see it.

 

[searstractorfan]

ok, thanks Ill have to feel for it!!!