4L80e: swap year 2000 into 2005?

Ryan Arnold · January 14, 2020

I'm wondering if I can swap the 4L80e from my 1999.5 GMC Sierra 2500 into a 2005 Sierra 2500 that is being sold with a "blown" transmission? The newer truck is in much better condition overall and is priced well.

davester · January 14, 2020

Yes, you can swap it in. You probably will also either need a new torque converter or swap the torque converter as well, as I recommend you not use the one from the blown transmission (as you don't know how well it works or what crap may be in it).

Note, this is specifically about the 4l80e. The 4l60e is supposed to be much more specific, and has much more limited interchange options.

Edited January 14, 2020 by davester

Ryan Arnold · January 14, 2020

Well that is good news, thanks for the speedy reply.

tylerroebuck · August 16, 2022

I have a 2002 Chevy Silverado with a blown 4l80e transmission. Will a transmission work that comes from a 2006 Chevy Silverado?

redvett · August 16, 2022

Make sure you flush out the cooler lines and the cooler before installing the replacement trans.

davester · August 17, 2022

Yeah it should work no problem.

Also make sure the torque converter is properly engaged with the pump in the transmission AND that it doesn't come out as you are installing it. If, when the transmission is bolted to the engine and the TC is pressed up against the flexplate and doesn't easily move (as in, pushing with your hand) back into the transmission, unbolt the transmission, move it back a bit, and then get the TC engaged with the pump again. There should be some space between the TC and the flexplate when the trans is bolted to the engine, so you have to pull it towards the flexplate to bolt them together.

Failure to do this, you likely will destroy the pump in the transmission once you start the engine, necessitating removing the trans, replacing the pump, and cleaning metal bits from the transmission...