Which Seals to Replace On E420 Trans Swap??
 

Hey Forums Friends;
I have a 722.366 Transmission from a 1994 e420 w/118,000 miles Already removed from the chassis. It will be installed into another 94 e420 with toasted Trans.; so Absolutely NO Issue with Fitment...
My question for Anyone in the know; "Exactly" what "Seals" and/or other parts should i replace on the Trans. BEFORE installing it into the car?? I will change the trans filter and fluid once trans is installed into the car. What seals are there - other then the front pump seal, rear seal and main seal?
I am Hoping to extend life/function of trans for as long as possible by doing this preventive maintenance Now and Not having to worry about it for Quite some time....Any and All advise/recommendations are Greatly Appreciated.
THANKS All............Chance

Before installing I would replace the front pump, reverse clutches, 3rd gear clutches and piston seals at the front left and right hand side of the trans. These item will greatly extend the life of the tranny and can be done in about an hr since you already have it removed.

That's the first I've heard that third gear clutches should be replaced. Is that a common wear item?

The third gear clutches I change because it's one more set of clutches that I can get to while having the front pump out.

Thanks. Benz Tek. I will keep this in mind when I have my B3 clutches and oil seals changed.

I'm preparing a similar swap. This is the list I have gotten from this thread


Front Pump & Seal
Rear Seal
Main Seal
Piston Seal
3rd Gear clutches

Any other ideas? I recently replaced the Tranny mount and flex discs so those are good.