Chevy 4L60E to 4L80E Transmission Swap

    Goodbye 4L60E, Hello 4L80E

    Ken BrubakerPhotographer, Writer

    This 1997 Chevy Suburban has a 5.7-liter engine, 6-inch suspension lift, and 35-inch tires. The truck is regularly used off-highway and to tow trailers. It also has a propensity for killing its 4L60E four-speed automatic transmission.

    The 4L60E transmission has been used in a slew of 1/2-ton GM trucks and SUVs, and it has even appeared in some GM 3/4-ton trucks. It's a decent transmission that has proven itself a workhorse. However, if you use your truck hard, it can be a weak point that can fail-in some cases, repeatedly.

    The owner of this rig could've kept paying to have the 4L60E rebuilt, but instead chose to replace it with the much beefier 4L80E four-speed automatic transmission. The 4L80E has been used in a number of 1/2-, 3/4-, and 1-ton GM trucks over the years. Upgrading from the 4L60E to the 4L80E is akin to going from a Dana 44 axle to a Dana 60--you'll add some weight, but also add durability. According to GM Powertrain information, the 4L60E has a maximum engine torque rating of 360 lb-ft and a maximum gearbox torque rating of 610 lb-ft.

    The 4L80E has a maximum engine torque rating of 440 lb-ft and a maximum gearbox torque rating of 885 lb-ft. What this boils down to is that the 4L80E offers an 80 lb-ft and 275 lb-ft improvement over the 4L60E in both areas, respectively. Is there a downside? Well, the 4L80E is slightly heavier and offers a less crawly First gear ratio (2.48:1) than the 4L60E (3.06:1).

    Matt Dinelli and his team at Attitude Performance in Arlington Heights, Illinois, have completed a number of 4L80E swaps on fullsize GM trucks. We recently had the chance to witness one of these swaps on the aforementioned vehicle. Here are the highlights.

    Bottom Line
    The total price of this particular swap was a hair under $4,200. This included the complete transmission with torque converter (about $2,300), all of the conversion components, front driveshaft, and labor. Keep in mind that this figure was for this specific rig, and costs can vary significantly by vehicle and the price of the transmission and torque converter being installed. If you're a do-it-yourselfer, a kit is available from Attitude Performance for approximately $700. It includes everything listed in the first-captioned photo at the beginning of the story.