Common problems in the A4RA, B4RA and M4RA transmissions are harsh upshifts, downshifts and forward engagements, while reverse engagement is fine. These problems can be caused by a broken CPC (clutch pressure control) valve spring. The spring is located in the secondary valve body and is not available from Honda. Sonnax has developed a replacement spring 88894 that has a wire diameter larger than the OE design. This significantly reduces the stress on the spring, preventing future breakage.
Early Design = .260" spring pocket; .480" long spring
Late Design = .390" spring pocket; .625" long spring
Contact a Sonnax Parts Distributor.