Brining this back from the dead…

I finally got the trans into the truck, but it’s only going forward. Anything outside of park is forward. The tune used is questionable, the indicator on the cluster shows 1 no matter what position the shifter is in. I’ve read that’s a common problem on some 4l80e swaps.

This sounds more mechanical than electrical. Like there are clutches that are stuck?

 

Sounds like the Manual valve is not connected to linkage at VB ,

 

I should have included this in my post. Took that right before installing the filter and pan.

 

I am not saying its not there as its not clear with photo position but I do not see the nail that prevents the linkage from sliding over and the wear mark on the shaft at case would indicate that the shaft at lease in the pic is further in than it had been riding. So I the nail/retainer pin in the case? If not the linkage shaft could easily slide right over and off the manual valve even during the very first movement to gear .

 

I will be honest, I’m not sure what you’re talking about. I will look through some diagrams to see if I can figure it out. I sure hope that’s all it is. Moving the arm the shift cable connects to with no cable, it still feels like it’s “doing something”. Bad description I know.

I did pull the PRND switch connector, and it wouldn’t crank. Still showed 1. Pulled the harness connector, would start but still stuck in 1st.

I will dig through some diagrams and probably pull the pan to check.

thanks for the reply!

 

Well frank, you were spot on…



I’m not exactly sure where the nail or retainer I am missing goes, but I will keep searching.

 

Ill try and find some pics tomorrow it goes right at end of the linkage shaft under the plate of vb . But I am having trouble findinding a good pic or diagram showing it.

 

See it there right under the plate at the end of the shaft and yes it is literally a nail lol . That is what keeps the rid from moving away from the manual valve

 

I was lucky enough that a local trans shop had a junk 4l80 in the corner and they guy gave me the pin. Fixed that problem.

Next problem, I have no reverse. D-3-2-1 all want to go forward. I haven’t checked the shifter cable adjustment, but even sliding the shifter back from P I don’t feel it kick into R. From a little bit of searching it sounds like the servo pin may be short, and not engaging the band. I sure hope thats it.

 

Something isn’t right or is missing in the reverse servo.




that’s the order everything is in it. I believe Im missing a washer, but the pin seems to travel more in the piston than what I’ve seen in other videos.

I plan to use this to check the travel

 

I believe my problem is that I am missing the spacer for the servo pin. This is a picture with the spring on the pin. I believe that c clip land should be just about flush with the piston body?

 

I left the OE short spring out.

 

Yes in fact you should have to push down hard to compress the spring to even get the clip in. You have found your issue with reverse . Missing parts,

 

Being I don’t have a tool, I’m using the push and measure methods. Reverse does not want to engage and grab like it should. I think I need an extended pin. With the pin clipped in to the piston and the short and long spring in, I am able to push it all the way to bottom. It does go in a little ways, and it takes more effort to go all the way to the bottom, but I’m able to do that. I know my methods of measuring aren’t precise, but it doesn’t match what I’ve seen in videos.

 

You should only have to push it a small distance before it compresses all springs and stops the drum . Also when you do think you have it be sure and air check. You will not when the band actually applies it will turm the drum a short amount each time. This of course assuming car off ground and not in park .

 

I bought a used reverse servo assy and made my own band clearance tool. Worked well

 

Originally I had no reverse in my 4L80 when installed and I was working with the pin in the reverse servo piston but then discovered that somehow my velvebody slider piston wasn't connected to the shifter so I dropped the valve body a little bit to get the Shifter connected to the long piston slider on the valve body and now the vehicle has no gears forward or reverse. What could i have messed up in dropping the valve body slightly off the trans case that would cause all gears to be neutral?

 

Well I am not sure what combinator could cause movement but . literally every ball in the case could have come out of position and then be compressed into some position they didn't belong causing a host of issues . No movement assuming you did put the little nail in this time and linkage rod in place,
I would first put a gauge on it and see if i have pressure. I did I would pull valve body completely down, Inspect it and case for damage, Use thick gel to put all ***** back here they go and replace and try again. the ***** are about .250 so if you went lower than that they could certainly have moved from proper place probably would not even have to drop that low ,
But I have never tried to run an 80e with all the ***** out of place or missing .
I mean would seem off chance wise but for instance if a ball ended up in the fwd clutch feed and the direct clutch feed it could eliminate fwd and rev movement .

 

Thanks for the help man I'm starting to think the new filter didn't seal to the pickup bushing and it won't make pressure without the seal. Wondering what hardware I need to buy to do a pressure test

 

for a one time use get a cheap gage and line with a 300 plus measurement on amazon will be fine