January 16, 2014
Some vehicles equipped with an A340 or AW4 series transmission may exhibit complaints of no converter apply, overheated converters, lack of cooler flow and/or transmission fluid overheating. A worn lockup relay valve sleeve due to continuous oscillation of the lockup relay valves can cause these complaints. Wear in the 1st land (see illustration) may cause a loss of Solenoid 3 signal pressure, which may prevent the valve from stroking fully into the TCC apply position. When the TCC is signaled ON, wear at the 2nd and/or 3rd lands may allow converter apply pressure to leak to exhaust, creating reduced apply pressure and cooler flow.
The Sonnax replacement kit 97855-27K provides two drop-in-place sleeves that are sized to reuse the OE valves. These sleeves are made from highly wear-resistant billet aluminum, which provides a much longer wear life then the OE cast-aluminum sleeve. The Sonnax sleeves also provide almost 50% more support for the valves, which helps reduce wear and hydraulic leakage. This sleeve kit allows the salvage of an expensive valve body, and provides increased durability compared to the OE design.
This kit works with the 3-solenoid and 3-land lockup relay valve. It does not fit any applications with four or more solenoids.