4L80 Question

[Twodogbiteme]

Hi Everyone,

I have an 85 350/TH400. Swapping to a 4L80 for the OD. Not a 4L80E, its a hydramatic 4L80. Does this use a TV cable like the 700R4 or cable like the TH350/TH400? Thanks in advance.

 

[Matt69olds]

The 4L80 is fully electronic, no TV cable or mechanical speedometer provisions

 

[Twodogbiteme]

After further research, I found out the trans that I found has been modified with a manual valve body . I might still purchase though bc the price is right, and I can rebuild it and get the stand alone controller for it. Otherwise, I'll just locate a 700R4. Which is the better option is now the question at hand.

 

[Matt69olds]

If it has a manual valve body, you don’t need the controller. Only problem is it’s a manual valve body, meaning whatever gear you put the shifter in, that’s the gear it goes in and stays in. No automatic shifts. Depending on who’s valve body, and model, it may be a forward or reverse shift pattern. It may also require some wiring and switch for the lockup converter.

You can install a stock valve body to get the automatic shifts back, but then you still need a controller Chances are the transmission will need to come apart to have parts reinstalled that were removed for the manual valve body. If you can find a part number or manufacturer of the valve body that would help.

The transmission might still be a good deal, last manual valve body I bought for a 4L80 was 600 bucks (that included a transbrake).


If you have no plans for power upgrades, and just have to have a overdrive, a properly built 700 would be much cheaper and easier.