This is what happen, coolant had leak in the trans and I still drove it for a few more day before I parked the car for a month, and now I just finish installed new radiator and flux the trans with two case of Dextron III plus new filter.oil look good and red now.
I drove test for a few miles, and now it start lock up every time I put in reverse.Look like the reverse and first gear they are locking at the same time when I put in revers or D.When I increase the acceleration it roll for a few feet and when I release it stop like braking, and when I put in N mode the car still roll forward like it still in gear.any one know of this type of transmission problem?
BTW just did new fluid, new filter,up shift cable adjust,shifting link adjust,brake and E brake not lock still the same, I was thinking some thing have to do with the reverse piston (B3 friction plate)in side the trans and or B2 band both too tie cause of water, or Valve body stuck. any Idea? Do you guys have any opinion that I can fix or adjust some thing without dropping the trans.thanks guys help me please..
edit it is a 722.351xx trans.

'Bad enough you left transmission fluid contaminated with coolant in the tranny
overnight...BUT for a Month...The amazing thing is that the MB moved at all!

Try some Trans-X ,But I'm pretty sure you're looking at a rebuild.

Normally,I NEVER would suggest adding ANYTHING to an MB Automatic Tranny
EXCEPT the correct ATF...BUT in your case,you're already out of the plane
without a parachute,nothing can make the situation worse!

__________________
'84 300SD sold
124.128

okay, I'll flux it one more time hope it help, if not I will drop it for a rebuilt.thanks

Drop the trans oil pan. Check for residue or 'dust'.

If you find any - off to the re-builders for you.

Had this problem recently myself. Change over trans.

Changing out the oil and filter exacerbated the problem. - wasted my money on fluid and filter. You cant use them again in a rebuild tranny.

See this image. If you have this in there - bad luck..... rebuild time.

"MOST" of the time when the trans locks-up in reverse....you will find the reverse clutches so worn that the reverse piston is coming out too far & is hitting the K1 clutch drum & locking it down.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Mine has no residue or dust, but the oil look like strawberry color for the first flux and filter change. after the second flux and filter change now look red and good, waste two case of oil and two filter still no luck.sad sad..

Thanks M.B.DOC, I know soon or later I will drop the trans for a rebuild.
for now can I ask you some question?
If B3 piston worn and hit the K1 drum, how do I know or detect with out dropping the trans? will it make some noise? my don't have noise and sound like normal.
I don't have any metal cheap or dust in the oil pan and filter.
Don't you think the return spring for B3 piston and washer is to weak and cause it to lockup? or maybe the VB not release the pressure for the B3 (reverse) piston when I select in D? any though of B2 band to tie? cause in N mode car move forward like it still in first gear and in R mode it lockup(car won't move and stuck like braking)I'm very confuse any though please share...cheer

Have a read through this thread

1989 190E 2.6 B3 Replacement Question

Thanks for the link Ivanerrol. But mine The reverse dose engage, When I shift in R mode the only problem is, it look like lockup in both forward and reverse at a same time like the car in braking. and in N it move forward like the still in first gear. Any how I will drop the trans soon to find out what causing it and will update....cheer