Roasted direct clutches in a 4L60e

[NickG80]

Okay so I picked up a 97 EXSB 3rd door heavy half ton for cheap. It has roasted direct clutches. I planned to tow a travel trailer (6k pounds) for hunting and other trips with my boys. Also around the farm chores, getting hay, feed the usual. I have located a complete 350/4l80e/NP241 drivetrain with harness and computer. All in good shape. Gonna swap in the 4l80 and use the donor harness. Anything else I’ll need? I figure heavy half with a 4l80. That’s a pretty bulletproof truck. I figure I could rebuild the 4l60 but I’d be in the same boat again. I should also add that this transmission. Has already been built once by AAMCO and almost all the bushings are wasted and the input shell and direct drum are trashed. Opinions? Thoughts? Any known surprises to look for?

 

[df2x4]

Keep in mind that unless the drivetrains of the two trucks you're combining are exactly the same besides the transmissions (differential gears, engine, '96-'97 vs. '98-'00 PCM, etc.) you could have issues using the donor PCM and/or harness. Even if everything is the same except the differential gears you'll still have to re-tune the donor PCM to correct the speedometer and shift points. Gauges might be wired differently between years as well, I'm not sure. It might be easier just to keep your PCM and harness and wire in the input speed sensor for the 4L80E, then get the PCM tuned to control the 4L80E instead of the 4L60E. The input speed sensor is the only wiring change necessary at the PCM harness plugs, and it's just adding two wires and pins. The rest of the wiring can be done at the transmission end of the harness. Just throwing ideas out there.

You'll also have to move the transmission crossmember back a little on your frame, plus get a shorter rear and longer front driveshaft. Cooler lines are different as well.

I have a 4L80E swap thread here, but it was in a '97 C1500 so you'll have to deal with some things I didn't. Same year truck though, so I can help you with pinouts for the input speed sensor wires if you decide to keep your factory PCM. My factory service manuals have pinouts for all the '97 PCM harness connectors.

https://www.gmt400.com/threads/97-c1500-4l60e-to-4l80e-swap.38819/

Good luck with the swap! It's a good bit of work but IMO it's worth it if you plan on using the truck hard at all. The 4L80E is a great transmission. There are a few other members here who have done the same swap that I'm sure can help you as well.

 

[NickG80]

Thanks for the advice I had read your post before making my post. Update so I bought the drivetrain. I have located the input speed sensor wiring and removing it from the donor harness, I’m also swapping the 2 pins at the transmission connector. I plan to get new cooler lines and cooler. I’ll keep the 350 since it has half the mileage as mine and clean it up and replace all the gaskets in it. Backup for when my 224k engine goes.

 

[NickG80]

4l80e is bolted up cross members is in. Need to take the 2 transfer cases apart to swap the inputs.

 

[brianmcb]

I recently did the 80e swap in my 2005. Went pretty smooth. Only set back I had was when I tore the transfer case apart, I noticed the "pump rub" issue, so I had to wait a couple weeks for the repair kit to be delivered

95 rcsb, L33 5.3, hot cam, hp tuners, 4/6 drop

 

[NickG80]

Transfer case inputs changed, transfer case in everything is finished but the cooler lines and rear drive shaft it’s 2” to long! Might get it started this weekend!

 

[NickG80]

It’s been awhile since I updated this but it’s finished. If I didn’t buy the entire drivetrain out of another truck I would suspect I have completed this swap for $600, give or take. Very easy swap, driveshaft shortening is about all you cannot do at home in the drieveway, oh and pcm programming.

 

[Supercharged111]

Glad to hear you 4L80 swapped, I did too and the peace of mind of the trans and bigger diff is irreplaceable. Even better to hear you're up and running!