Adding shift kit to full manual control 4l80E?

[urbex]

Before anyone mentions it, yes, I'm fully aware of what it's like to drive a full manual auto trans on the street. I've been running a full manual valve body in the current 700R4 trans, and have also ran them in multiple other transmissions over the years. The 700 overheated on the last trail run, is coming out, and will be replaced with a 4L80E in preparation for a future 489BBC swap as well. I have all the parts for the motor, just haven't found the time to start building it, but miss driving the K5...so I'm at least getting the trans in there for now, lol.

Some time ago I found an article detailing how to convert a 4L80E trans to full manual control via redirecting control of the solenoids to the pressure manifold assembly, and applying some modifications in the front pump - https://atracom.blob.core.windows.net/gears/2015/2015-03/2015_3_32.pdf

Appears straight forward enough, and is similar to what I did on several Jeep AW4 transmissions over the years, just without the pump mods. Though, I'm not all that familiar with the internal workings of the 4L80E transmissions, and wondering if adding a shift kit to this would be beneficial or cause circuits to potentially fight against one another? Or maybe it's not even at all needed on a 4L80 to begin with after doing this?

 

[1-ton]

You may not want to put a shift kit in a 4L80E. I have a trans-go shift kit in my 4L80E, and I only used part of it, in order to do the dual feeding that the kit can do. The dual feeding with a shift kit is not really the best way to do it, but it works. There are other parts of the shift kit that are problematic, such as the spring loaded relief valve and plate. These have been known to get cock-eyed and stick open causing trans pressure to get low, thus burning up the trans.

There are better ways to dual feed a 4L80E. A company called Sonnax has pressure valves that will correct the over pressure problems 4L80E trans is known for. Here is a video on the proper way to dual feed a 4L80E.

 

[urbex]

I'll have to take a look at that video when I get home tonight, and look up that Sonnax stuff...that PDF mentions dual feeding the clutch, and was just pulling the 2nd seal from the center support on the pump? Not that I'm arguing the points, just trying to get a better understanding of how this all works.

 

[Shawn]

So is it a known problem that full manual 4L80 over heat or is this only a problem on electronic MVB?

 

[urbex]

The issues as I understand it is that the full manual control sets up the trans to run full line pressure all the time, and that creates additional heat inside the trans. There are drainback mods that also need to be done in order to handle the additional fluid flow/pressure, and from what I'm gathering now, the shift kits don't properly address that heat issue.

But I'm still learning on the 4L80s too...

 

[Shawn]

I'll have to keep tabs on my trans temp gauge. I installed a huge cooler which runs after radiator so we'll see. My temp gauge is on the outlet line going to cooler.

 

[urbex]

Well....that was disappointing. Got the trans installed and wired up earlier today. Just took it for a spin, and this thing shifts just as soft and slow as stock, though I wasn't really getting on it either, though my 700 was quicker and harder even at low speeds.

I pulled amatuer hour duty, and forgot to pull the distributor cap before pulling the trans...yep, broke it, lol. So it's running funky now, and I didn't want to stand on it until I fixed that. I'll try some WOT pulls tomorrow.