4L60E 3-4 Z-PAK Clutch Pack, Single-Sided RZP-001

The 3-4 clutch is the part of a 4L60E that carries the load in overdrive, and it is the first thing to burn. A standard rebuild answers that with more frictions, which runs you out of room in the drum. The Raybestos Powertrain RZP-001 Z-PAK answers it differently: the frictions are single-sided, so the friction material and the steel it works against are combined into one thinner plate. You get more friction surface inside the same 3-4 drum without stacking the pack taller.

Single-sided construction also pulls heat out of the pack instead of trapping it between two lined plates, which is why core temperatures come down on the same duty cycle. Raybestos builds the plates so they resist coning under high stress, the failure mode that shows up on a single-sided pack when a truck is loaded, towing, or running a tight converter. That makes it a fit for fleet, four-wheel drive and commercial units that live under load, not just performance builds.

Bench work is the same as any 3-4 pack: pull the drum, get the old frictions and steels out, soak the new plates in clean ATF before assembly, then set clutch clearance with the correct selective plate and measure it - do not assume the Z-PAK drops into the stock stack-up, because the plate count and thickness are different from the factory pack. Air-check the drum before it goes back in the case.

Fits GM 4L60E units. Part number RZP-001. Ships from the USA.