saespyder

I have a 2003 c230k sedan with the 6-speed manual transmission. A few days ago it started to grind (I think) when upshifting from 1st to 2nd gear.

A few things:

1. It seems to reduce as the car warms up, but not completely go away.
2. It's only on the upshift into 2nd gear, no other gears and not during the downshift into 2nd.
3. It sounds like the sync takes a second to catch up and then it sounds like the teeth are grinding once or twice before locking.

I'm coming toward my service B date and wasn't sure if this was due to a lack of transmission fluid or something similar, or if the gears are actually worn down.

Also, I did search for a while on this, but came back with threads mostly dealing with the AT. Most of the fixes for those issues didn't seem to apply here, so I started this thread. If it has been covered I apologize.

LILBENZ230

I'm not familiar with the 6MT transmission. Can you check the fluid? Do you have a ton of miles and maybe the fluid should be changed?

saespyder

I was hoping to check the fluid this past weekend, but it rained the entire time. Soon, hopefully. The car has right around 70k miles so I don't expect anything dramatic, but I figured I'd ask before I let the dealer take a look.

Glyn M Ruck

This is a common problem. See all the complaints on the 204 forum. It's either the clutch not disengaging properly or the second gear synchro cone that is damaged. What confounds me is that it should be worse on the downchange into second but some others report what you do.

You can try an oil change & cold oil will always make the situation worse. It will improve as the oil heats up.

Merc's manual gearboxes are not the greatest I'm afraid. Somewhat agricultural.

I presume you are driving exactly as you used to? Have you done a lot of snap changes from 1st to 2nd on this car.

c2304pete

I had my 5th gear synchronizer go at 18k miles in my 05 C230k sedan. The dealer replaced the transmission under warranty. The new gearbox + labor was >$3k. They were very nice about it. I 've brought it back twice for hard shifting with no improvement. My wife, whose driven manuals her whole life, hardly has the strength to get it into reverse. They say they use synthetic gear lube. I was thinking when it gets warmer, I'll put some Red Line or Royal Purple in myself.

I have driven manuals my whole life. VW Golf x 3, Porsche 944T, BMW 535i, and Volvo 850 and I have to say while I greatly love my C class, the gearbox feels the cheapest of all my former rides buy a wide margin. It absolutely sucks. It's rubbery and vague. If you shift fast, it won't go into gear. When it's cold, forget about it! I have to move the car foward in little amounts until I find the right spot to get it into reverse. I consciously have to tell myself to fully depress the clutch and shift slowly. Takes all the fun out of driving!

It's a little disappointing and quite frankly surprising as the C class is the 2nd most popular car in Europe behind the Golf and most of them are manuals over there. I'm interested to find out who makes the transmission, ZF, Getrag or Borg?

I don't think I will buy another manual Mercedes. Not that anyone will offer manuals in the future anyway. DSG seems to be the future.

tommy

I certainly wouldn't recommend a Mercedes manual to anyone either - mine is very hard on the 1-2 shift when it's cold outside.

But mine does get much better when warmed up. Not as good as my 20-year-old CRX, of course, but better.

I agree with you - enjoy true mannies while they're out there, it probably won't be too long til you won't be able to get them new.

saespyder

Sounds like Pete and Tommy have similar issues, so maybe I'll just wait until I take it in for service to mention it.

I completely agree about the rubbery feel. At first, I thought, "A sporty car with a soft shifter - that'll be nice." Not so much for spirited drivng.

I noticed today that if I let pull out of first gear and let it settle in neutral before going into second it feels better/easier on the transmission. I don't know if that's because the RPM's are lower or it's just easier on the synchro, but it seems to help in the cold.

Also, what's the DSG?

C230 Sport Coup

I know a guy who runs royal purple oil in his manny, and never has had any shifting issues since changing the oil.
I had the same issues on other trannies I've had....called Redline, advised onf the proper product, used their stuff, problem solved.
Royal Purple has a tech line as well....check their website.