Mercedes Benz TCC Damper Valve and Sleeve Kit Sonnax Fits Late 722.6 Late model 722.6 valve bodies added a TCC damper valve at a previously vacant bore in the casting. This damper valve acts like an accumulator for the converter clutch. If there is leakage due to bore wear, signal oil can leak to exhaust, resulting in harsh TCC apply and lock-up. The highly wear-resistant sleeve incorporates o-rings to seal against previous bore wear, without the need to ream the bore. Annular grooves have been added to the Sonnax valve to better center the valve and prevent future wear. No machining required.