In GM 4L60-E, 4L65-E and 4L70-E units, the hammering effect of the 3-4 relay and/or 3-4 shift valves can cause the end plugs to wear, resulting in loss of 4th signal and/or D3 oil. Replace the worn OE end plugs with Sonnax 3-4 relay O-ringed end plug kit 77964-08K to restore hydraulic integrity and prevent loss of critical 4th signal and/or D3 oil.

• O-rings on the end plugs provide a positive seal
• Restores hydraulic integrity at the end plug