#20MS. The holding capacity of even the largest modulator plunger valve assembly does not supply enough line pressure to the low/reverse clutch to adequately hold the clutch in diesel or heavy-duty applications. This same issue will occur in gas and street applications as the vehicle ages and wear at multiple locations continues to rob line pressure. Sonnax has developed an innovative, dual-plunger valve drop-in replacement assembly that prevents repeated low/reverse clutch distress and burn-up. The inboard, smaller plunger valve has the ratio of the larger OEM plunger valve, but functions primarily as the engagement control for the low/reverse clutch. A small orifice along the valve axis prevents harsh or bang engagements by maintaining a controlled feed flow to the larger, outboard holding valve. This valve provides almost double the holding capacity to the low/reverse clutch as the OEM valve. Both valves are hard-coat anodized to prevent wear, and the newly designed sleeve is made from a highly wear-resistant grade of aluminum. A new spring is also included to work with the new valves. We have found this part to be bad on almost everyone we checked. (This part always wears out 99% of the time and should be replaced on every rebuild.)
• Innovative dual-valve design controls clutch engagement while nearly doubling holding capacity.
• Valves are hard-coat anodized to prevent wear.
• Newly designed sleeve made from highly wear-resistant aluminum alloy.
• Drop-in-replacement allows for easy and quick installation.