I've been trying to understand why all the witness marks are necessary.

For example, why mark the transmission output flange in relation to the driveshaft? I'm going to replace my transmission so obviously this mark will be lost.

The FSM also shows to mark the flex discs. Once these are replaced, that mark is gone too.

Wouldn't the driveshaft be balanced out of the car without flex discs and tail piece?

Also what type of self locking nuts are on the flex discs? Can these be acquired at home depot?

Bump....

The procedure is to put things back as they are. If you are replacing, however, as you say there's no way of doing that so marking the flex discs is a redundant procedure.

The nuts are a stiff nut variety that should only be used once. I don't know if home depot would stock such things. They are quite cheap at the dealer over here so I just go there instead of second guessing...

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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!
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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!

liquiddog, new flex disc kits normally include new nuts and bolts. Best to use OEM replacement parts if you don't want to spend the money for parts from your local MB dealer. Avoid buying cheap aftermarket flex discs, unless you prefer to repeat the job in short order.

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Fred Hoelzle

Driveline Parts Should ONLY be O.E. Mercedes,for safety reasons if no other.

If the Front Flex Disc "Goes Away" can the front of the Front half of the DS
drop down and "Pitchpole" ? Think of Pole Vaulter.

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'84 300SD sold
124.128

I got Lemfoerder flex discs (OEM from what I understand) a year ago. So I need to remove the driveshaft to do the center bearing this weekend, and again at the front to R&R the transmission in a month or so.

Does anybody have the part number for the bolts? I can't locate the part # on the diagrams I usually look at.

My research shows the part number is 1249901451. About $30 shipped for a set of 12. I'm going to go that route though because they are unusual lock nuts. It's almost as if they are tapered.

they are stiff nuts - the top of their holes are oval in shape which does the locking on thread job, home depot does not have them and they are fine pitch btw.

I have had to correct a flex disc once which involved removing the bolts n nuts, I applied blue threadlocker to the reused bolts and never had problems once torqued up.

I have the older original bolts from the original flex disc which have nylock nuts.

the marking of the Dshaft as explained by stretch is to put everything back as it was. I recall some pictures of a flex disc which was OE MB and it has numbers on it - the numbers should go back to the same area on the tripods - this was a very old service manual as I have not yet seen such a disc.

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1995 E300D - The original humming machine (consumed by Flood 2017)
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