75 280s transmission - PeachParts Mercedes-Benz Forum

thepossom · #1 01-10-2007, 10:18 AM

i just got my 75 280s "project car" running the other day and i am wondering if i have a transmission problem. i have an automatic and it seems to shift fine through the gears but i dont think it is going into 4th. about what speed should i be looking for the trans to shift with normal throttle opening... any tips where to start would be appreciated

Mike D · #2 01-10-2007, 01:09 PM

My '73 280 shifts into 4th at about 30 mph. Start yours out in the bottom shifter position and shift up through the gears. 1st gear is incredibly low on the automatics and yours may not be dropping all the way into it or it may be shifting so fast you don't even feel it.

cth350 · #3 01-10-2007, 10:44 PM

your car should start in 2nd. To get a 1st gear start. Put the lever down a notch before you touch the gas. Then floor it. -CTH

thepossom · #4 01-11-2007, 01:48 PM

i think you guys are right... it does seem to go through the gears if i shift it "manually". the tach says about 3000 at 55mph, seems a little reved up to me. is this normal?

Mark DiSilvestro · #5 01-11-2007, 04:23 PM

Despite the 4-speed automatic, there's no overdrive gearing on these cars.
My reference gives 3140 rpm at 100 km/hr (62 mph) for the W116 280SE, so "about 3000 at 55 mph" is probably in the ballpark.

Happy Motoring, Mark

Cephallus · #6 01-11-2007, 08:03 PM

Mine magically started upshifting to 4th after driving it around for a few dozen easy miles. It had been sitting 8+ years, and I'd done a fluid/filter service on it.

To echo the comments above, the lack of overdrive is apparent on the freeway. Mine screams like a banshee at 85mph.

archipeep · #7 01-12-2007, 06:03 PM

Quote:

Originally Posted by Cephallus

Mine magically started upshifting to 4th after driving it around for a few dozen easy miles. It had been sitting 8+ years, and I'd done a fluid/filter service on it.

To echo the comments above, the lack of overdrive is apparent on the freeway. Mine screams like a banshee at 85mph.

At least yours gets to 85mph

cth350 · #8 01-12-2007, 08:05 PM

mercedes straight 6 motors aren't shy about high rpms. -CTH

Cephallus · #9 01-13-2007, 04:09 PM

Quote:

Originally Posted by cth350

mercedes straight 6 motors aren't shy about high rpms. -CTH

Agreed!

After the carb cleanout/rebuild, I've got a lot of niggling problems...ineffective choke, rough idle, poor fuel economy...but she runs like a raped ape with the pedal to the floor...