Another weird trans issue- '85 300SD - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 10-21-2013, 06:09 PM

I was working on a friends '85 300SD, and driving it, I noticed a weird transmission shifting issue. Starting out from a stop wit my foot to the floor (shifter in D), it seems to start out in second, and immediately shifts to third and then to fourth. This all happens before 20 MPH. When shifting it manually, it starts out in second (shifter in 2), and winds out with good power (can feel the turbo working), and shifts firm when shifter is moved to the next higher gear. It shifts very smooth, and almost feels like a CVT. The RPM is steady around 2,500 throughout all the shifts until fourth, at which time the car is accelerating along with the engine. I thought it might have a vacuum problem (after all it is a CA spec '85 with seemingly a mile of vac hoses and valves), so I hooked up just the modulator and VCV to vacuum. I also checked the bowden cable, and it is adjusted all the way tight (should not shift until throttle let off a little), still no change. I also checked (although not thoroughly) the kick-down switch and associated fuse. I don't know how to test the solenoid in the trans. Is there an easy test or fix without removing the trans? Any help would be appreciated. Thanks in advance, Rich