Tool Required VB-FIX Required
- Shift concerns
- UD/B3 brake clutches burned
The B3 orifice control valve often sticks in the casting bore, preventing proper stroking of the valve and flow control to the UD/B3 brake.
Refurbish the valve bore and install the Sonnax oversized B3 orifice control valve and spring to prevent future sticking issues.
Oversized B3 Orifice Control Valve Kit
In U151E/F, U250E units, the B3 orifice control valve and spring are biased by SLT solenoid (torque signal) pressure to control the UD/B3 brake. Regulated line pressure is routed from the 4-5 shift valve through the B3 orifice control valve to apply the UD/B3 brake. When this valve sticks, flow will diminish or no flow will go to the brake, resulting in burnt clutches or shift complaints.
- Hard-coat anodized aluminum valve maintains consistent bore-to-valve clearance at temperature variations, which helps prevent seizing of the valve
- Valve front spool has been greatly lengthened to provide more stability in the bore
- Annular grooves provide better valve centering in the bore and keep the contact area lubricated to prevent seizure