4L60E 1350 Series Transmission Slip Yoke 3-3-6081X

This is the transmission-end slip yoke for the GM 27-spline output shaft, machined to accept a 1350 series U-joint. It carries part number 3-3-6081X (cross references T3-3-6081HP and N3R-3-6081X) and replaces a worn or wrong-series yoke on the 4L60E, 4L65E, 700R4, 200-4R and TH350, as well as the Muncie M20/M21/M22, Saginaw, and Borg Warner T-5, T-10 and T-56 manuals that share the same spline.

The usual reason to replace one is a leak or a vibration. The yoke's sealing surface rides inside the tailshaft bushing and seal, and once that surface is grooved or rusted a new rear seal will not stop the drip, and a loose fit wears the extension housing bushing out. The other common reason is a driveshaft build: going from the stock 1310 joint to a stronger 1350 joint on a truck or swap car means the transmission yoke has to change to match.

On the bench, check the fit before you order: 1350 cap diameter is 1.188 in with a 3.625 in joint width, and centerline of the ears to end of spline is 5.5 in. Many GM slip yokes look alike, so measure your old one or confirm the number stamped on it. Clean the splines, put a light coat of ATF or assembly lube on the sealing surface so it does not tear the new tailshaft seal, slide it on, and set the pinion angle when the driveshaft goes back in.