Re: ultramatic direct drive clutch wont release until hot

Posted by Peter Packard On 2013/11/10 2:56:33

The front pump bushings replacement is extremely critical on rebuilds, as little as ten thou combined wear between shaft and bushes will result in a "potential to slip" High Range and DD Clutch assemblies. However your problem appears to be more of a pressure monitoring/sequencing/valve body problem than a bush problem. The supplement to the 56 Twin ultra overhaul notes includes the dimensions and details of all of the springs and valves in the bodies, because it is extremely easy to put them in backwards, or a spring into the incorrect body orifice. The bodies come off easily from underneath without removing the box. It is extremely important to use the correct inch-pound torque on the valve bodies, as incorrectly torqued valve bodies was a constant problem when Ultra's were returned after warranty replacement. I would first check the DD pressures and High range clutch pressures. if these are within manual specs, then your front pump bushes and shaft are ok. Governor pressure reading is a PIA, especially with the PB motor but it will let you know what the governor is telling the rest of the box. PT