I have recently noticed an automatic transmission malfunction on my '95 E320 wagon (W124) with 130,000miles.
The transmission operates silky smooth in all ranges, EXCEPT, when coasting up to a stopsign at about 10mph, I get a Rough Downshift (clunk).

[I have had this problem on my 123 diesels, and it always turns out to be a vacuum problem [leak], which is reducing vacuum to the modulator.]

I checked the M104 engine for loose vacuum lines/hoses and have found none. I pulled the vacuum connector from the second intake plenum and checked the line with a mighty vac & it held good vacuum (I think that on leads to the vac modulator on the automatic trans).

[I also have a check engine light on, but believe this is unrelated to the timing of the trans problem. (this car has the original engine harness).]

Any suggestions or components to check/replace are welcome.
TIA
Steve Whiteside

Steve,

Did you ever find out why your transmission was making that noise? I have a similar problem.

Thanks!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)