4L60E Raybestos Pro-Series Kevlar 2nd/4th Band RPS77765

This is the 2nd/4th (2-4) band for the GM TH700-R4 family: 700R4, 4L60, 4L60E, 4L65E and 4L70E, 1982 and up. It is the Raybestos Pro-Series performance version, part number RPS77765, with a 2.6 inch wide friction surface and heat-treated anchors.

The lining is a Kevlar fiber blend instead of the standard paper-based material. Kevlar holds up better to heat, so the band keeps its grip when fluid temperature climbs during towing or hard launches. Raybestos rates the material for heat up to 700 degrees F.

A burned or glazed 2-4 band is a common 4L60E failure. The truck slips or flares on the 1-2 shift, or it loses 2nd and 4th gear completely and starts off in 3rd. Band wear usually comes with a worn servo, so check the servo pin length and the servo piston seals before you close the case. A band this width works with the stock servo or with a larger Corvette-style servo.

Bench notes: soak the band in fresh ATF for at least 20 minutes before installation. Line up the anchor end with the case anchor pin, and look at the drum surface as you go. A scored or blued reverse input drum will wear out a new band quickly.