Accessories

Symptoms:

• Code 628, 1744, 1740
• Reduced converter clutch life
• Planetary failure
• Bushing failure
• Loss of lube oil

Cause:
Casting bore wear at the bypass clutch valve and plunger sleeve wear allow converter apply and release pressure to exhaust.

Correction:
The Sonnax reamer restores the bypass clutch control bore while the OS valve re-establishes bore fit and extends life through additional spool support and annular grooves.

Worn bores in the Ford CD4E and Mazda LA4A-EL converter bypass line-up reduce TCC control and cooler flow. This results in bushing or planet failure, reduced converter clutch life from overheating and often results in codes 628/1744/1740. Slippage codes are often generated as the unit comes up to operating temperature. As the temperature rises, valve control becomes poor and excessive clearance creates excessive leakage of converter pressure.

The Sonnax oversized bypass clutch control valve kit features a tightly toleranced sleeve and plunger valve to prevent leakage, and an oversized and improved design bypass clutch valve.

• Plunger valve and oversized bypass clutch valve have extended spools for better support and annular grooves to prevent wear due to side loading
• Lubrication plugs increase lube and converter pressures by tapping into line pressure instead of depleting converter feed
• Plunger sleeve manufactured from highly wear-resistant aluminum
• Hardcoat anodized aluminum valves combat premature wear

Note:
This kit cannot address high line pressure in the PR balance circuit, which can break up parts and reduce flow into the converter/cooler circuits. For information on that repair, see part number 47760.

Content:

• Bypass Clutch Valve
• Plunger Valve
• Bypass Clutch Sleeve
• Lubrication Plugs (4) 1 extra

SONNAX Installation Instructions