Shifting Problem from 2nd to 3rd on 600SEL
 

My car is 600SEL 1992. Recently I'm having a problem the occurs always (cold/warm) when shifting from the 2nd gear to the 3rd gear. It's like slipping (or maybe you call it a flare) it's like when I'm driving and it's the time that the car must shift to the 3rd gear it will act like if it was on the Neutral position for one second then it will shift. I noticed that if I decreased acceleration it will shift better. It's shifting normal from the 3rd gear to the 4th gear.

The vacuum system is working properly and adjusted properly as well.

Could that be because of bad 2nd gear clutch plates?

Up...

Try increasing the modulator pressure by a turn OR 2 clockwise on the modulator. Do you use synthetic trans fluid? IF not then try changing to synthetic.

Thank you M.B.Doc. I did increase the modulator pressure clockwise one then two turns same thing. I have the regular Titan AT fluid. Ok I'll follow your recommendation and use synthetic AT fluid. I have a question here:
Assume there is no synthetic AT fluid in this world, do you think changing the 2nd gear clutch plates will solve the problem? Thanks a lot :)

third will be your problem which is the front drum.this can be done with trans down but without having to totally diss trans.just take out front pump.while you are in there replace reverse clutches and front pump o ring.

Ok, after what you said I decided to install a new (used) transmission from a low milage 600SEL (used in Japan). Then I'll use synthetic AT fluid as M.B.Doc recommended with a new filter.