89 300CE trans failure - ALL gears don't work out of nowhere..
06-04-2016, 07:00 PM
#1
Junior Member
Thread Starter
89 300CE trans failure - ALL gears don't work out of nowhere..
Hey all,
I've owned this coupe for over a year and while it did have mild rev flare on the 2-3 gear change, and pretty sharp downshifts, it didn't display any of the usual signs of a failing trans - always shifted in drive or reverse quickly and cleanly, no strange noises, just a solid car with about 157k miles on it now.
About a month ago I drove it, parked it, left it overnight.. Went to use it the next day started it, put it in gear.. and it wouldn't move. I shifted it into drive, reverse, neutral, park... Nothing. No weird noises, no pool of fluid under the car, it simply won't go. Most transmission experts (both for MB and in general) I talk to say maybe one gear would go out, but all of them at once is HIGHLY unlikely. So..
At first I thought maybe the gear shift bushing fell apart, so I got under it and saw that it was fine. Coupler nut still there. If you out the car in park the pawl does engage, so that seems to be working properly. I didn't inspect the vacuum actuator valve, so I bought a new valve and will get back under the car tomorrow. Of course, that's a long shot, but it's only 60 bucks and the shifts were a little rough, if it failed that would explain the complete lack of trans function.
So - am I missing something else simple? If the internal pump failed wouldn't it leave all the fluid under the car? Or am I simply living in denial, and just need to replace the trans? The car is worth it so give me your honest opinions guys.
I've owned this coupe for over a year and while it did have mild rev flare on the 2-3 gear change, and pretty sharp downshifts, it didn't display any of the usual signs of a failing trans - always shifted in drive or reverse quickly and cleanly, no strange noises, just a solid car with about 157k miles on it now.
About a month ago I drove it, parked it, left it overnight.. Went to use it the next day started it, put it in gear.. and it wouldn't move. I shifted it into drive, reverse, neutral, park... Nothing. No weird noises, no pool of fluid under the car, it simply won't go. Most transmission experts (both for MB and in general) I talk to say maybe one gear would go out, but all of them at once is HIGHLY unlikely. So..
At first I thought maybe the gear shift bushing fell apart, so I got under it and saw that it was fine. Coupler nut still there. If you out the car in park the pawl does engage, so that seems to be working properly. I didn't inspect the vacuum actuator valve, so I bought a new valve and will get back under the car tomorrow. Of course, that's a long shot, but it's only 60 bucks and the shifts were a little rough, if it failed that would explain the complete lack of trans function.
So - am I missing something else simple? If the internal pump failed wouldn't it leave all the fluid under the car? Or am I simply living in denial, and just need to replace the trans? The car is worth it so give me your honest opinions guys.
06-06-2016, 01:55 AM
#2
Member
I guess every car part has a life-span and an auto gearbox would not last forever. Mine was 1990 300CE 3.0 12V with an auto gear box as the original equipment, and the gearbox gave up on me (no gear except the reverse could work) in about 2008. That was about 18 years; mileage was about 180,000km, but being a car used in Hong Kong, gear-change and kick-downs were typical routines every day to overcome hilly and need to overtake slow traffic on the highway. The bad habit of shifting to neutral (I used to drive a stick shift) at traffic lights also contributed to unnecessary wear and tear. The auto gearbox was eventually overhauled regardless (the workshop's advice was removing the gearbox was not an ordinary affair so get everything fixed and replaced as far as possible), and a year later it was further replaced with a manual gearbox which I sourced from Europe. The other option would be to replace it with a used auto gearbox, but you never know if it would last much longer to justify the labour. However, the ease of DIY, availability and reliability of used parts, and hence the cost-benefit analysis at your place of residence may be different.
