I have a 1985 190D with a 5 cyl, 2.5L non-turbo diesel. With the shift lever in drive, the automatic transmission quickly skips through 1st, 2nd, and 3rd gear and is in 4th gear by the time the vehicle reaches 5 mph. As you can imagine, this makes for some pretty poor 0-60 times. If I manually select the gears (2,3, Drive) the transmission shifts reasonably smooth and the car is sluggish, but driveable.

Some history on the car: I bought the vehicle from a friend who had a transmission overhaul a year and a half before I made the purchase. The tranny worked fine for him for the first year, and then suddenly experienced the problem I described. I’ve been driving the vehicle for almost a year manually shifting it (feel free to scold me...) and have checked the following things:

Fluid: Clean, proper level, no sign of degradation

Control cable: freely moves and returns when actuated from under the hood. When I had the tranny pan off, I checked the motion of the valve that the cable operates, and it moved freely and through it’s full range.

Vac Pressure: I disconnected the hose at the transmission and connected a gauge with a long enough extension hose so that I could read the gauge while driving. At idle I measured 10 inches of vacuum. As the vehicle accelerated from a stop, the vac would go to zero, and then increase to 10-12 inches as the top end of 2nd gear was reached (remember I can’t manually select 1st gear). After manually shifting into 3rd, the vacuum would drop to 0 and climb to 10 or 12 at the top end and so on. After parking the car and shutting down the engine, the vacuum dropped to 0 after about 30 seconds.

One more thing, the tranny has recently been contaminated with water (much after the shift problem started). Here is an excerpt from my post elsewhere on this forum:

Back in March I discovered my transmission fluid was the color of a strawberry milkshake. I replaced the radiator with a new one, drained the tranny and torque converter and flushed the system. Everything was fine for a couple months and then the tranny started acting up again. Yup, more water contamination. We have a pretty good analytical lab at work so I gave a sample of the fluid to a friend and he ran a couple tests on it. He found 2.5-3% contamination of WATER. No sign of antifreeze.

“t walgaumuth” and “old deis” suggested I take a look at the top of the tranny for a missing or defective vent. While I have the tranny dropped, I might as well attempt to fix the shift problem. Any suggestions you might have will be appreciated.