I own a 1984 300GD with a 5 speed manual gearbox (717).
If the gearbox is in neutral and I release the clutch, a loud rattling sound emanates from the bell housing/gearbox area. Originally, I thought it might have been a problem with something in the clutch but after having worked out how a clutch works, I'm now thinking it could be something in the front of the gearbox; possibly something to do with the splined shaft.
Is anyone familiar with these vehicles? Can anyone suggest what my problem may be?
Is this gearbox specific to the G-Wagon only or is it the same box in some of the mercedes cars?
Are parts expensive?(rhetorical question - of course they are).

Any help is greatly appreciated.

Oli

P.S. I'm in Australia so parts can be extremely difficult to come by.

Does the rattle go away when you put pressure on the clutch pedal? If so I'd place my bet on the throw-out bearing. Not what I'd call an expensive part, but you have to remove half of the drive train (drive shaft and tranny) to get at it. Not sure if the MB manual shifts have pilot bushings, but if you get into it that far, you might as well replace the pilot bushing while you're in there.

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Mike Tangas
73 280 SEL 4.5

Yes, the rattle does go away when the clutch is depressed. By throw out bearing, do you mean thrust bearing? I am going to pull out my gearbox soon and replace the clutch as I already have a new pressure plate and clutch plate. I'm just waiting on a thrust bearing to arive from germany. I only hope that there is nothing wrong with the gearbox.

Oli

Throw-out bearing/thrust bearing same part, different names. That's is more than likely the source of your rattle.

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Mike Tangas
73 280 SEL 4.5

I've never heard a throwout bearing called a thrust bearing. A thrust bearing is the bearing in an engine that prevents the crankshaft from moving fore and aft.

My 300E with manual transmission rattles slightly when clutch pedal is released. There is no tension on the throwout lever at that time, so it is free to rattle. There should not be tension on the throwout lever, if there is, the bearing is contacting the pressure plate and spinning. The throwout bearing is only packed in grease, and only designed to turn whenever the clutch pedal is pressed. If the bearing rides on the pressure plate all the time, it won't last long. It's just as much trouble to replace a TO bearing as it is to replace the clutch, at least 98% as much work. Replace the pilot bearing while you're there. Yes it has one, all manual transmission cars have a pilot bearing or bushing.

Good luck,

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Larry Bible
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles

Those people that stand on the clutch waiting for the light to change know all about throw out bearing. It is correct that a thrust bearing is a bearing that keeps a shaft from wandering axially.

Some of these cars have a return spring attached to the throwout fork. If this is broken or loose, you will get a rattling sound. The throwout bearing should be in light contact with the throwout fork when not engaged. Either the spring is gone or your throwout bearing needs replacing..

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Jeff Lawrence
1987 300e
1989 300e
2000 Dodge Grand Caravan SE

For interest.

There are several different names for the bearing in question which are:

1) Thrust bearing
2) Throwout bearing
3) releaser bearing

These are all the same part. In Australia, we call them thrust bearings.

No-one seems to think there is a problem with the actual gearbox. Am I correct in assuming this?

Thanks everyone for their comments.

Oli