4L60E/4L65E/4L70E 300mm Stock Stall Torque Converter

This is a remanufactured torque converter for the LS-based GM 4L60E family: 4L60E, 4L65E and 4L70E four-speed automatics. It is a 300mm unit with a 30-spline turbine hub and a carbon fiber lockup (TCC) clutch, built to the stock 1400-1600 RPM stall range so it drives and locks up like a factory converter rather than a loose performance piece. It is intended for the LS-engine transmissions behind the 4.8L, 5.3L, 6.0L and 5.7L LS1.

It interchanges with GM converter codes TMBX, TMAX and TWBX and factory part numbers 24206642, 24208325, 24210919, 24213393 and 24227088. This is the later LS-based converter and will not fit the early 700R4 or pre-LS 4L60E, so match it against the unit coming out of your transmission before you install it. The stub, pilot and overall depth differ between the early and late converters, and that is the number-one reason a converter ships back as a no-fit.

On the bench this is a straight swap during a rebuild or whenever the old converter is suspect: contaminated with clutch material after a burnt transmission, shuddering on TCC apply, or ballooned from overheating. Pre-fill it with a quart of ATF, then seat it fully onto the pump. You should feel it drop and rotate through two distinct steps as the hub engages the pump gears and the turbine and stator splines line up. If it sits proud, it is not seated and the bolts will pull the front pump apart when you tighten the bell housing.

Check that the converter bolt holes line up with your flexplate before final assembly; a factory-correct converter lines right up, but LS engine and transmission mixes from different years occasionally sit half a hole off. Replacing the converter on a fresh rebuild is cheap insurance, since old clutch debris trapped inside a used converter will circulate back through the new build and take it out. Ships from the USA and carries a 2 year warranty.