foreyes

My independent shop did a fluid and filter change, he replaced the pressure regulator valve spring (Sonnax) per my request, the old one was indeed broken. The shifting is improved, but it still has a harsh 2-3 upshift, not nearly as frequently as before. The old trans fluid was very dirty, but no metal particles were found. There are no error codes either. What should I do next? I am going to disconnect the battery overnight to let the shift control module reset itself. My Indy quoted me $3500 for a full rebuild.

tirona

no metal particles is good news. it's good thing you changed the fluid/filter and the broken spring. i wouldn't disconnect the battery, but just do the tranny reset procedure: get in the car, close the door and make sure everything is closed. then turn in key to position 2 (when all the lights turn on but NOT start the car which is position 3) while at the same time push down the gas pedal all the way for 10 seconds, then turn key back to position 0 while releasing the gas pedal. wait for at least 2 minutes, and within these 2 minutes don't do anything, don't remove the key, don't open windows or doors, don't turn radio on etc. now tranny is reset. you can go for a drive around the block and drive the car how you always do, so tranny adapts to your type of driving.

also you could try to keep the tranny in W mode. as you know in S it will start in 1st gear, while in W will start in 2nd gear. who knows, maybe in W mode the 2-3 gear change will not be as harsh. i don't think you need a rebuild, hopefully with the reset or in W mode everything will be fine. good luck.

foreyes

Thanks again tirona, I will do the reset procedure instead. Thank you again for your advice, the shift problem is so much better after the pressure regulator spring replacement and fluid / filter change. I love the E, other than this problem, this car has been completely trouble free at 230,000 miles. I'm also wondering about adding a 2000-2002 w220 S500 vs. a 97-99 w140 S500.

tirona

foreyes, is the shifting still harsh?
regarding w220, i was looking at a 2001 s500 not that long ago, but i was strictly advised to stay away from 2000-2002 models since they are very problematic, but the 2003-2006 ones are pretty good. if you like w140 then that would be a better choice. they are better built for sure than w220. i have had a 97 s320lwb for a while now, and it's a wonderful car. the main parts i have changed are water pump at 70k miles, fuel pressure regulator, and blower motor regulator, but the car is only drive 4-5k miles a year, mainly weekends and long trips. also feels heavier and more comfortable than w220. s500 would be a better choice since w140 is a heavy car, also it will have same engine as your e420 (m119) which i'm sure you know how good it is.

foreyes

Thanks for the advice, the shifting is still harsh, slipping between 2-3 and 3-4 upshifts. I did the TCM reset procedure twice, and the winter/summer switch doesn't seem to matter. What next... A new TCM? A new conductor plate?