Hi all, I'm having some issues with my clutch - I'm hoping to avoid dropping the trans...

Background info:
1980 euro 300d 4 speed with about 208k miles on the clock...
full clutch kit with less than 5k miles on it.

It all began with a leaking clutch slave, which I replaced in January 2012...prior to that no issues whatsoever with clutch. About 4months later (on a warm day), the clutch began slipping after a long drive on mountain roads. I noticed it was fine when cold though. For some reason, I figured it was time to replace clutch, so I had a full clutch kit dropped in. Car ran fine for a while, until it started exhibiting the same symptoms again...which led to this thread:

slipping clutch question euro 300d

It seems the issue I have is a clutch release bearing that's partially loaded with the pedal up, so the clutch is not fully engaged - also, after about 10 mins of operation, I hear a chattering when the clutch pedal is depressed, which leads me to believe there is termendous pressure on the release bearing. While driving, I also hear a low humming noise.

I've adjsuted the eccentric several times to get it to the point where the pushrod is at its shortest hoping that the return hole is open; this seems to work fine for a while, but the issue still resurfaces.

At this point, the car is just sitting on my street as I don't want to drive it until I figure this out. I'm begining to think the slave cylinder I replaced in early 2012 is faulty, as the condition occurred after this. I'm contemplating putting in new slave, master & pushrod so I can rule these out - from what I see, the eccentric is doing its job, as anytime I try to adjust it, I can clearly see the pushrod length change.

If that doesn't work, the next step would be to drop the trans so I can see what's really going on in there. However, I'd like to leave this as a last resort, as everything was replaced, and I don't really have much time to wrench on this car at the moment.

I appreciate any input/suggestions.

Cheers!

There is an early and late clutch slave for w123 cars. Could you have the wrong one?

Sounds like the transmission, needs rebuilding....if there is noise there is probably a bad bearing some where.....or maybe the gear oil is low? May also be a flywheel problem.

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I've read that it is absolutely important to make absolutely sure that the clutch system is properly bled - no air - no air at all allowed.

Are you absolutely sure that that is the case?

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Sounds to me like he's got the opposite problem- too much throw or stackup keeping pressure on the pressure plate somehow. But I don't know what to say other than tear it apart. It might even be hard to figure out once it's in bits....

I would be wondering if I had used the right parts for the car...

For one thing, there are different lengths of master cyl pushrods, different slave cyls, different release bearings.

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

I was going to do a little research before posting about this but before you pull the tranny it might be worth investigating. I installed a clutch in my Euro TD and when I was done and tried it out the clutch would engage when the pedal was barley off the floor. I adjusted the eccentric and it helped a little. Turns out my clutch master push rod was too short. Could it be you are having the opposite problem? Both clutch master cylinders in the pics are exactly the same except for the length of the push rod. The difference in length is 6mms.
I have installed several clutches and never new there was any difference in masters. I don't believe the early and late slaves can not be interchanged.

Actually there is a difference, The long push rods have a BLACK plastic top and the short ones have a white top...hummmm

Attached Thumbnails

 

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

I suspect the pressure plate may have a broken finger causing the clutch to be partially released.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Thanks for all the responses! I'm pretty sure the clutch kit is the correct one as I had ordered this from Phil (may he RIP) and he pulled the parts using my VIN. The only part I didn't get from Phil was the slave cylinder, which I just bought from the local NAPA for convenience as I needed the car to be on the road.

I am quite sure I completely bled all the air out of the clutch system, as my pedal is firm and had good feedback following the installation of the slave (I used an 80ml vet syringe hooked up to the clutch slave bleed screw to push fresh fluid up). I've used this method on other brake/clutche jobs and never had a problem.

However, I'm totally confused as to why MB has several iterations of clutch master cylinder pushrods and even from what it sounds like slave cylinders.

I think my only option now is to put in a new clutch m/c, slave & pushrod to hopefully rule these out before pulling the trans out. Unless anyone else thinks of another strategy. Thanks!

Yah this thing with the master push rods is a puzzle. What I did was dig out my old master cylinder and push rod (I never throw things away that could be rebuilt later) and compare them. It was obvious the one in the car was shorter and when I switched them, all was well again.

There is an "early" throwout bearing and a "late" t/o bearing. I once pulled the tranny twice before someone enlightened me to that fact, one has a slightly higher "shoulder".

How far off the floor did the pedal rise before the clutch engaged?
And free play at the other end?

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Hi Stevo, the pedal is almost to the top before the clutch is engaged. After much fiddling with the eccentric adjustment, the best I've been able to achieve is releasing the clutch slightly around mid-point (actually somewhere between mid-point and fully to the top of the pedal ROM).

There isn't much free play to speak of though...

Also, is there a stark difference between the earlier type slave cylinder and later?

If you don't have a shorter m/c pushrod and are going to buy a new m/c anyway, you might try grinding the pushrod you have a bit to see what that does.

I think the two slaves have different sized fluid lines.

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80 300SD (129k mi) 82 240D stick (193k mi)77 240D auto - stick to be (153k mi) 85 380SL (145k mi) 89 BMW 535i 82 Diesel Rabbit Pickup (374k mi) 91 Jetta IDI Diesel (155k mi) 81 VW Rabbit Convertible Diesel 70 Triumph Spitfire Mk III (63kmi)66 Triumph TR4a IRS (90k mi)67 Ford F-100 (??)

The two slaves have different bolt patterns so that shouldn't be an issue, cant switch em.

If you pull the kick panel you could use a mirror and good light to see if the push rod end is black or white. That might be a clue. The T/O bearing could be wrong but You dont want to pull the tranny quite yet.

The later (yours) T/O bearing has the lower shoulder (where the fork rides) so if the early one was installed (higher shoulder) I dont think that wouldn't produce the problem you describe,

silly question, but ..You do have the one piece aluminum Getrag gear box as opposed to the two piece steel box. they are easy too tell apart.

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

The FTE brand M/S push rod has a ball at the end that fits into a sort of socket but it would still probably work cut short and rounded.

Both early and late slave hydraulic lines are the same (12mm)

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1985 Euro 240D 5 spd 140K
1979 240D 5 spd, 40K on engine rebuild
1994 Dodge/Cummins, 5 spd, 121K
1964 Allice Chalmers D15 tractor
2014 Kubota L3800 tractor
1964 VW bug

"Lifes too short to drive a boring car"

Sorry for the late response...I barely got home and was out in the rain trying to get a good look at that darn pushrod.

Bad news...the pushrod I have is white...I was hoping it's black which would make sense, but no, its white.

Of course, these type of things only happen to me, so I'm not really surprised. I'm not really sure what to do at this point...I don't want to start throwing parts at it, but it looks like I may be forced to do that in lieu of dropping the trans.

And as rs899 said earlier, I might not get much from opening the trans up either. I'm stumped...

I keep thinking about this possibility, as I stumbled across another post similar to mine which resulted in a bad pressure plate. However, I have less than 5k miles on mine, and can't bring myself to terms with this as a possibility...