What rpms should my 280CE be at at certain speeds? - PeachParts Mercedes-Benz Forum

eagle-co94 · #1 10-08-2007, 09:56 PM

My car is an '85 grey market, so I'm not sure if that means much. I'm trying to find out if the tranny is shifting correctly. Could someone let me know what rpms your car is in at various speeds so I could verify on my car?

I'm thinking 15, 25, 45, 55, 65 and 75

On the drive home when I bought it the car sounded like it wasn't shifting into top gear on the highway. I officially registered it today and put the tag on it, so I can post my numbers tomorrow by lunch time.

deanyel · #2 10-08-2007, 10:30 PM

An unanswerable question - without knowing more about your transmission and rear axle ratio, in which case you could calculate it. Euro cars often have higher axle ratios than U.S. models, and often offer more optional ratios.

eagle-co94 · #3 10-08-2007, 10:47 PM

Actually it's a very answerable question. I'm not asking you to tell me what my car should do, but what it might do based on other owners results.

I know there are other grey market cars out there. That's why I worded the question that way.

I know nothing about my tranny & axle ratio, so any information would be helpful.

How many forward gears are there on a US spec tranny? I sold my 300CD and didn't think to count the shifts. Is there a way to tell what gears are in the tranny or rear end based on part numbers, tags or some sort of markings?

Perhaps someone might have access to a dealer brochure for '85? Curious if it would list gear and tranny options.

CamelotShadow · #4 10-09-2007, 12:43 AM

Mine is a 500 sec euro

OOOh
I drive it
& leave the shifting up to ole mocha
It shifts when it wants too
& as long as its smooth & happy
what do I care...

Maybe when I;m done w watching temp & oil pressure & idle
I;'ll start with the rpm shifts...

I can add that when it was smogged
15 mph reported 1370 rpm
25 mph reported 1341 rpm

seems backwards but thats what it says

t walgamuth · #5 10-09-2007, 07:18 AM

that car should have a 354 rear end. I don't know the shifting speeds off the top of my head though, but they should shift at full throttle pretty near the redline, which is 6500. I would think it will hold til at least 6200 at full throttle. It is a four speed if an automatic.

Just guessing.....45, 65, 80, 100. at full throttle.

Tom W

eagle-co94 · #6 10-09-2007, 09:48 AM

I'll try that today. At part throttle it doesn't want to shift much at all. I was told that a shift kit would possibly resolve the problem. What're the odds that my tranny is shot? It seems to be stuck in 2nd. On the way to work I hit 100 at 5000 rpms, then dropped to 80 at 4100. After coming to a stop it didn't want to shift back into the gear that allowed me that. I'll do some research tonite and give some detailed info on shifts, but it felt like on only had 3 forward gears on the way to work, and only 2 by the time I got here.

eagle-co94 · #7 10-09-2007, 08:20 PM

Okay, so this tranny seemed to get worse all day. I have to put it almost to redline to get it to shift, and then it chirps the tires. Starting off in firstt I can almost spin the tires at will due it not shifting. WAY too many RPMs. I'm afraid I'm going to hurt the motor. Tranny fluid is nice bright red, not overfilled, and doesn't smell bad.

t walgamuth, I think you're right on the rear end gear...1st gear is worthless after probably 5 mph.

I can get it to go into 2nd and third by shifting near redline...but 100 comes at 5000 and I don't want to know how fast I'd have to go to get it into 4th!

It looks as though I can put it into neutral and back into drive and it'll pick the correct gear. Are there solenoids I can just replace?

Any suggestions? I'm tempted to put the 190E on the road as it runs & drives just fine...it just "looks a little odd."

Throw me a bone!

eagle-co94 · #8 10-10-2007, 08:56 AM

This is this mornings results:

Tranny shifts into 2nd at about 4800 rpm's, chirping 2nd.
Tranny shifts into 3rd at about 5400 rpm's.
Tranny shifts into 4th at 6500 rpm's around 82
I can then slow down to no less than 72 or the tranny will drop down to 3rd. I want to say that 72 was at about 4200 rpms, but can't remember anymore numbers at this point.

Manually shifting the car doesn't seem to accomplish anything. If I'm going to do that, I'm going to use a clutch.

Were these rev-happy cars? I'm used to my SBC that redlines around 5800-6000.

eagle-co94 · #9 10-11-2007, 09:12 AM

Okay, here's the latest: On the way home last night I decided to take a few corners and kick the rear end out since the tires are shot (14's swapped from the 300CD) and burn a little rubber off. After I did this on 2 corners and left some nice tracks the tranny makes the 1-2 and 2-3 shifts JUST FINE! Shift points are around 2000 rpms if I'm light on the pedal, the 2-3 is around 4000 if I'm more than a 1/3 into the pedal or so. The 3-4 shift is still way out there, but I didn't even get a chance to get up to about 85 to get it to shift. Much better, but I doubt this is a permanent fix.

DslBnz · #10 10-11-2007, 03:45 PM

Quote:

Originally Posted by eagle-co94

Okay, here's the latest: On the way home last night I decided to take a few corners and kick the rear end out since the tires are shot (14's swapped from the 300CD) and burn a little rubber off. After I did this on 2 corners and left some nice tracks the tranny makes the 1-2 and 2-3 shifts JUST FINE! Shift points are around 2000 rpms if I'm light on the pedal, the 2-3 is around 4000 if I'm more than a 1/3 into the pedal or so. The 3-4 shift is still way out there, but I didn't even get a chance to get up to about 85 to get it to shift. Much better, but I doubt this is a permanent fix.

Sounds like your kickdown switch is hanging up. Its that solenoid button underneath the gas pedal you engage when you floor it for maximum acceleration.

You can unplug it or replace it. But thats what they do when they stick.

eagle-co94 · #11 10-11-2007, 09:41 PM

You know, I'll honestly admit that you were messing with the newb here and sending me out for a raisin peeler or left handed smoke shifter. You were completely RIGHT. When I got in the car after work I looked thinking "man, this guy is really screwing with me" and sure enough, it was there. I pushed on it and nothing...then it popped UP. I pushed it in several times and each time it came back out. The car sat for 3 weeks from the day I bought it until I drove it to work after putting the tag on it Tuesday, so that may have had a hand in it. It still doesn't like going into 4th unless you're doing about 85 (which is about 6250 rpms). I'm on the hunt for another 300CD anyways, so I think I'll just spray it with some lithium grease so it moves freely and let the new owner worry about 4th gear. Don't worry...the trunk triagle and bumpers are staying with me.