I sent the following e-mail to Richard Easley tonight and thought some of you who have followed this thread might have some input as well:
I found your B2 FAQ through the MercedesShop.com news group. I'm part way through the replacement and have a few questions. First, some background:
Car: 1989 560 SEL (126 chassis, 722.350 transmission, 100,000 miles)
Symptoms: Flaring 2-3 shift since we bought the car last December with 86,000 miles. Intermittent flaring/slipping in 3-4 shift, worsening lately. Last Thursday, no 3-4 shift at all. None since.
Action: Ordered new B2 piston and bushing. Disassembled tonight to replace B2 piston, ran into the following issues and questions:
1. Pulled old piston out and the push rod came with it, falling into the drain pan. The push rod has a groove on its shaft, nearer to one end than the other. On re-assembly, will the grooved end go in toward center of transmission or toward the case?
2. The bore for the piston shaft has what appears to be a teflon bushing toward the inside of the transmission, with what appears to be a black rubber lip seal on the casing side, no teflon or steel sleeve on the casing side. Lip seal is damaged. Seems impossible to replace the existing bushing without removing the valve body. Is the new bushing used to replace the rubber seal, with the phlange on the new bushing facing the case side of the transmission? If so, do we just pull the rubber seal? If not, do you know if the rubber seal is an available part that can be replaced with the tranny in the car? I have seen no mention of this in the FAQ or any newsgroup discussions.
3. The old piston came out in one piece, and initially looked fine. Then we noticed that the new bushing did not slide smoothly over the end of the shaft of the old piston. End of shaft is very slightly mushroomed and has one rough spot. Enough to restrict movement. Leads us to think we're on the right track. Might you concur?
Any thoughts you have would be greatly appreciated. My "helper" is a veteran wrench on American engines and transmissions, new to MB. This is my first look inside the transmission. Thanks for a great website and your giving spirit.
Any comments or help would be most useful. Thanks.
'02 C230 Kompressor
'89 560 SEL "Frau BlueCar" (retired April 2004)