4L60E to 4L80E conversion

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mdiacont322

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I have read this is an extremely good idea, but I cant really seem to find a good write up on it, step by step, how to do this from start to finish. Does anyone have any good information or pictures or even a link to a good "how to" for this?

Any info is appreciated, as always.

Thanks,
Mike
 

992dr

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I have read great reviews from members of other forums. Its very popular when doing an LS swap. I had inquiered a while back about doing an LS based swap, even with my built tranny, a lot of other members suggested the upgrade.

If you are capable of rebuilding one, you can find them for short money and do the work yourself. Or, theres plenty of reputable shops that sell them to your specs.

I'm almost posotive the only mods are wiring harness, driveshaft and tranny mount. Oh and maybe the bellhousing or something.

Check out LS1truck.com and performancetruck.net .
 

steamroller

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http://www.fourwheeler.com/techarti...y_4l60e_to_4l80e_transmission_swap/index.html

From what I understand you don't have to buy the adapter harness they used, I believe it's 4 wires that need to be spliced into your original harness and ran to the PCM.

Someone on here should have the wiring info posted, if not they should be able to tell you what wiring additions need to be made
http://www.pacificp.com/forum/index.php

The 4L80e is roughly 2" longer so the driveshafts will have to be modified, or you may luck up and find a compatible replacement at a junkyard with the correct length. Trans crossmember will have to be moved back. Input gear for the transfer case will have to be swapped to a 32 spline or just get a transfer case that was behind a 4L80e or manual trans. Only thing I don't like about the 4L80e is the 2.48 first gear vs 3.06 of the 4L60e.
 

retorq

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That is an awesome write up!! I wonder why he didn't just move the tranny crossmember back on the frame though ... When guys put a 700/4L60 in the second gen Camaros we typically just move the front holes to line up with the factory rear holes and drill 2 new ones. Seems a lil easier ...
 
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mdiacont322

mdiacont322

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right now, the tahoe is at the transmission shop getting the 4L60e rebuilt. Its the most cost effective option right now. I would love to do the swap just so i dont have to worry about burning the 60 up, but its $$$. Gotta pay to play lol.

as far as the first gear between the two, how much of a difference would be felt as far as speed and acceleration?

Mike
 

steamroller

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If you have 3.73's now it would be like you had 3.23 gears in 1st gear. 2nd gear on the 4L80e is also a little higher (numerically lower) @ 1.48 vs 1.63 for the 4L60e so a little bit of gear is lost there too. I would test drive a Suburban, 3/4, or 1 ton truck with a 4l80e just to get an idea of what it would be like. With a small block the 3/4 ton Suburban I drove felt sluggish, with a big block or diesel it would be a different story. There are a couple places that sell a 2.75 gearset that can be installed, which would be a good compromise but would add to the cost. They are a good trans either way

Art Carr sells a manual control harness for the 4L80e if you wanted to go to a fully manual with it.
http://www.artcarr.com/page/news/10.acpp

With yours being 4wd there aren't alot of options unless you want to run a divorced transfer case. If you want overdrive it's the 4L80E, 5 speed NV3500 and NV4500, or the 6 spd ZF 650 from the NBS trucks. I'm not sure how much work it would be to use the ZF trans, if it would work at all. Hopefully this rebuild will last and you won't have to worry about it.
 
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