Looking to Buy a Wounded C320 6 Speed
 

It's a 2005 with 155,000 miles on it. Right now it's having clutch hydraulics problems and the seller is having difficulty getting it fixed. I may buy it even with those problems, I've fixed hydraulic clutches before, I know they can be trickey. Any thoughts?

What's the problem? Parts availability? It has to either be the master or slave.

A few years ago the clutch began dragging on my '88 190E 2.6 five speed. I figured
it was the slave, but since I change fluid regularly I was surprised. Upon looking at the removed OE slave the pushrod was mushroomed on the end. Upon disassembly the bore was perfect.

I got a new one from Pelican - even had the same casting number and was reasonably priced. Cleaned and greased the fork and end of the pushrod, and it's been fine ever since.

Hint: To bleed the system, open the slave bleeder valve and run a hose from the RF caliper to the slave. This bleeds it from the bottom up, so the air is quickly purged. If the brake fluid is of unknown age or dark, flush the brake system first so new fluid goes into the clutch system.

Duke

05 c320 6spd is just about the best w203 you can buy. M112 is by far the most reliable engine they put in it, 05 is post facelift with a lot of improvements both inside and out and rare manual.

heard those motors were junk,not like the early v6 engines

C240/c320 M112 is the early v6. You're thinking of the 06+ m272 with the bad balance shaft and intake failures.

Yes, I believe the engine is an M112, I already have two (C280's) so I'm tooled up for it.

I was just talking with the seller and he said his mechanic said the clutch and clutch slave cylinder were out. The mechanic would fix it for $1000 and he dropped his price by that same about. I'm planning on driving an hour and a half tomorrow to look at it, hope it's worth it. I may end up driving a clutchless car back, which I've done before but not that far.

I did look for parts and Mercedes clutch parts are rare, can't find any here.

Rock Auto has both the master and slave cylinder in stock. You'll have to drop the trans to replace the slave cylinder. Might as well throw in a new clutch as well.

Every slave I've seen has been outboard. Are you saying the slave on this car is inboard?

I looked around for that part and did notice it's round, shaped like a doughnut. From the picture I couldn't figure out how it works or where it's mounted. It needs a new clutch anyway.

It does seem like low miles to wear one out, my last clutch wore the car out at 350,000 miles. Either they are bad shifters or something broke.

It looks like the throw out bearing a and slave cylinder are integrated into one component.

Yes, I see that. Seems like a good idea, unless it leaks.

I don't see how you bleed it though.

Did the US delivery C320 actually come with a manual transmission? I thought only the C240 did.

Yes, it did. You could also get an slk320 with manual - I saw a couple og those at MBCA track events. I had a 06 c230 sport with 6 speed manual and no sunroof. Balance shaft sensor (?) went bad at 115,000 so I got rid of it. I remember when Autoweek did an article on the c350 with 6 speed stick, praising MB for finally binging the Americans a car to complete with the 3 series.

All these cars are hard to find. I think the current model slk launched with a 6 speed available in the base 4 cylinder turbo.

That won't win any design awards in my book. Do you have a link to a parts book illustration to show how it's configured? As already asked, how the hell do you bleed it?

OP said the master and slave are already out, so that would mean the transmission is out, too, if it really has to be removed to access the slave.

Duke

Get a larger book.

Actually is is a great design that goes way back to the 1978 or so SAAB and more main stream with the Mazda designed M5OD trans found on 1988 + Ford Ranger and full sized trucks.

Some advantages are:

Less parts / assembly needed to make the system work.

Self adjusting ( this can be had with an external salve also however )

Smaller external footprint of the bell housing / trans.

Less friction in operation ( think of how a disc brake caliper works. )

No need for a snout on the trans to guide the release bearing.

[QUOTE=Duke2.6;3806736]The slave is hollow and concentric with the trans input shaft.

There is an external bleeder.

One of the elements that make for an "elegant design" in addition to simplicity, low cost, and reliability/durability is "maintainability". Slave cylinders are common replacement items. They rarely last the life of the clutch or transmission, even with frequent fluid changes (but that's not how mine failed as I explained in my previous post), so ease of replacement is important in my book since I keep cars a long time.

Most hydraulic clutch release systems have many of the features you mentioned, but my award for "best design" is the mechanical linkage in my '63 Corvette - simple, low cost, low friction, durable/reliable, and in the event of a problem, easy to access for repair.

The worst is the cable in my Cosworth Vega. The OE routing forced it into an S-bend, which is a very bad idea. After having to replace it at about 30K miles I analyzed the problem and rerouted it in a smooth arc. That replacement is still there, but it needs to removed from the clutch pedal bracket and firewall every few year to run a graphite lubricant emulsified in a petroleum distillate carrier that evaporates (I use Lok-Eze) to reduce friction.

Duke