240d 4 speed manual tranny hard to engage clutch - PeachParts Mercedes-Benz Forum

petecooke · #1 12-23-2019, 07:26 PM

I have a 240d 4 speed manual transmission that is hard to get into gear. I've replaced the master and slave clutch cylinder. I've tried 2 different master clutch cylinders and I believe the problem is inside the transmission.

When you press on the clutch it's very difficult to put the car in any gear. This is not a air bleed issue. The slave clutch cylinder has a rod that pushes into the transmission and this is where the problem seems to be.

I have over 100k mile on the clutch since it's last been replaced. I was planning on pulling the transmission and replacing the clutch plates while I attempt to resolve this problem.

Does anyone know what the clutch slave cylinder rod pushes on inside the transmission? I've never pulled a transmission but I'm planning on doing this within the next few weeks.

I'd like to order any parts that I might need before I start this project. I feel like something is bent inside the transmission and it's not allowing the clutch plates to fully disengage in order for my to put the car in gear.

I'd love to find a picture of the clutch slave cylinder rod pushing on whatever it touches inside the transmission.

Any ideas/advice?

TIA

pete

bigpanda16 · #2 12-23-2019, 08:05 PM

Possible for the stamped steel clutch fork to be letting loose.
That is the part that the slave cyl rod pushes on which is attatched to the throw out bearing that pushes on the fingers of the pressure plate.
It is not unheard of for fork to wear a hole in them after heaps of miles unlubricated

Sugar Bear · #3 12-23-2019, 08:59 PM

A very nicely done article by Scott 98...look at the first picture in post 4. The clutch fork goes from one side to the other over the input shaft and holds the throwout bearing in place. The rod on the slave cylinder pushes on one side of the fork and the other side/end of the fork pivots on a ball stud.

You seem certain it isn't an air problem in the hydraulics, how so? I'm asking because I don't want to see you R & R the clutch unless needed.

Good luck!!!

How to replace a clutch in a 240D - Pictorial

petecooke · #4 12-23-2019, 09:48 PM

Quote:

Originally Posted by Sugar Bear

A very nicely done article by Scott 98...look at the first picture in post 4. The clutch fork goes from one side to the other over the input shaft and holds the throwout bearing in place. The rod on the slave cylinder pushes on one side of the fork and the other side/end of the fork pivots on a ball stud.

You seem certain it isn't an air problem in the hydraulics, how so? I'm asking because I don't want to see you R & R the clutch unless needed.

Good luck!!!

How to replace a clutch in a 240D - Pictorial

I've bled the clutch multiple times using a few different methods discussed in the forums and nothing seems to help the problem. I'm sure it's not an air issue. Pulling the tranny is the last think I want to do in the cold since I don't have a garage.

pete

petecooke · #5 12-23-2019, 09:46 PM

Quote:

Originally Posted by bigpanda16

Possible for the stamped steel clutch fork to be letting loose.
That is the part that the slave cyl rod pushes on which is attatched to the throw out bearing that pushes on the fingers of the pressure plate.
It is not unheard of for fork to wear a hole in them after heaps of miles unlubricated

I pulled the clutch slave cylinder to see what the rod was pushing against in the transmission and I noticed there seems to be a crack in the metal it is pushing. I assume this is the clutch fork.

pete

Sugar Bear · #6 12-23-2019, 09:08 PM

If you replace the clutch, be certain the valve cover does not leak and then inspect and/or have on hand;
a clutch alignment tool,
friction disc,
pressure plate,
throwout bearing,
pilot bearing,
clutch fork,
flex discs,
driveshaft spline boot,
spline grease or a substitute,
shifter bushings,
trans oil (ATF?),
the plastic spacer if used between the slave cylinder and the bell housing,
center driveshaft support and bearing.

petecooke · #7 12-23-2019, 10:32 PM

Quote:

Originally Posted by Sugar Bear

If you replace the clutch, be certain the valve cover does not leak and then inspect and/or have on hand;
a clutch alignment tool,
friction disc,
pressure plate,
throwout bearing,
pilot bearing,
clutch fork,
flex discs,
driveshaft spline boot,
spline grease or a substitute,
shifter bushings,
trans oil (ATF?),
the plastic spacer if used between the slave cylinder and the bell housing,
center driveshaft support and bearing.

Are the pressure plate and friction plate always replaced together? Any recommendations on clutch disc/pressure plate manufacture? Sachs/LUK/RhinoPac?

pete

Sugar Bear · #8 12-23-2019, 11:14 PM

Yes the pushrod goes against the fork. If you see a crack then I'd say you found the problem. The pressure plate, friction disc and throwout bearing are almost always replaced together often along with a flywheel resurfacing.

If the fork is bad and the clutch worked ok as in it didn't slip, chatter, engaged no more than halfway up the pedal travel you may be able to just replace the fork, clean and lube the fork ball pivot and replace the throwout bearing. It is a lot of work to remove any transmission but fortunately I found the 123 240D an easier one of many. Don't try to replace the clutch without an alignment tool.

Good luck!!!

petecooke · #9 12-24-2019, 12:34 PM

Does anyone have a part number for the clutch fork? I can't seem to find it online.

Thanks,

pete

Sugar Bear · #10 12-24-2019, 01:14 PM

What year?

t walgamuth · #11 12-24-2019, 04:02 PM

I suspect the pressure plate having a broken finger or two. If that happens it will not release fully and make it hard to shift. The fingers are normal wear items which will give up after x number of shifts....millions probably.

petecooke · #12 12-26-2019, 08:00 PM

I pulled the transmission today and replaced the clutch fork and throw out bearing from a spare transmission. I didn't replace anything else.

I've attached some pictures. You can see the hole in the fork. After reinstalling, the clutch feels much easier to push but it's still hard to get into 1st gear. I'm think something is damaged inside the transmission.

Could this be a synchronizer problem?

The pressure plate definitely shows wear. Would this cause the gears to be hard to engage?

It only took a few hours to pull and re-install. I guess if I pull it again to tear the transmission apart, I'll replace the pressure plate and friction disk.

It was a lot easier that I thought it would be.

Thanks for all the help.

pete

petecooke · #13 12-26-2019, 08:03 PM

The round post that's screwed into the transmission looks worn. Doesn't anyone have a part number for this? I will replace when I do the friction disk.

t walgamuth · #14 12-26-2019, 09:12 PM

There is very significant wear on the pp fingers. There also sometimes are broken springs inside the plate ...if they fall down into the works things can get caught and cause problems. The pivot also looks very suspect.....not smooth and round like it should be.

There is also the possibility that the flywheel is worn deeply which also can cause disengagement difficulties.

petecooke · #15 12-26-2019, 09:31 PM

Thanks t walgamuth.

I will order all the necessary clutch re-rebuild items that was posted by Sugar Bear in a previous post. The clutch fork pivot definitely had some wear.

Should I buy a new flywheel or get it resurfaced? I've seen new flywheels for around $60 online. It's probably 40-50 to have resurfaced.

pete