4L60E, 4L65E, 4L70E

Fits either of two locations

Symptoms:

• Delayed Reverse
• 3-4 Clutch burned
• Burnt Low/Reverse clutch
• 2-4 Band burned
• 3-2 Bind-up

Cause:
Wear of the bore plug in the forward and reverse abuse valve bores can allow valuable oil pressure to exhaust.

Correction:
This increased diameter drop-in plug restores proper clearance in the valve body and requires no tools for installation.

The bore plug in GM 4L60-E, 4L65-E and 4L70-E units is held loosely in place with a coiled spring pin, allowing the opposing spring and oil pressure forces to stroke it within the bore.

This constant oscillation causes the plug to wear and allows PR oil at the low overrun valve and 3-4 clutch oil at the 3-2 downshift valve to exhaust at the abuse valves. This excessive oil loss can result in delayed apply of the Low/Reverse clutch and a tie-up of the 3-4 clutch and 2-4 band. This Sonnax Forward and Reverse abuse bore plug resolves these problems.

This plug is used in two locations in the valve body: to separate the forward abuse and low overrun valves, and to separate the reverse abuse and 3-2 downshift valves.

• The Sonnax plug has an increased diameter to restore proper valve body clearance in the circuits
• The plug has a smaller retaining pin hole to reduce plug movement that results in wear
• No tooling is required for this bore plug
• Drop-in Zip Valve™ parts install quickly and easily

37789 Instruction Sheet

Sonnax 4L60E Level 3 Transmission Build