Where did I go wrong with these flex disks?
Front one is to the right and the marking and writing was to the rear of the car.
The rear one on the left the marking and writing was to the front of the car.

When I redid the carrier bearing I must have been tired and reversed one.
What is the correct installation way and If I get lemforders then how do I know which way to install those right?

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1984 W123 300CDT

Anyone else from the flex disk threads have any ideas?

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1984 W123 300CDT

These are new? What brand where these?




There is a couple of designs of disks. The type you have pictured, when I install them, I have the thick part (not the thin part) of the disk "pushing" on the other bolt during the rotation. If that makes sense.

But it appears you did it that way. So it might be just a bad disk.

.

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1983 123.133 California
- GreaseCar Veg System

I haven't done this and there is nothing in the FSM, just swapping out the prop shaft.
I imagine you'd have to have the three protruding bushings facing the right way.

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83 SD

84 CD

The three protruding bushings (the ones that stand up higher than flush with the flex disk) fit into recesses in the yoke. Since there is a drive yoke on each side of the flex disk, there are three protruding bushings on each side.

This design means the bushings take most of the lateral (rotational) stress, and the bolts are there simply to hold the bushings tight.

There is also a particular way the bolts are inserted into the flex disks, and the best policy would be to check the manual. Operating from my own (faulty) memory, I believe the bolts are all inserted from the "outside" in toward the middle of the car. So on the front flex disk, the bolts are all inserted from the engine side of the car and the nuts go on the back. For the rear flex disk, the bolts are all inserted from the differential side and point forward, with the nuts going on the forward side.

When you have the driveshaft off, make sure the front yoke (attached to the transmission) is tight. There is a large nut in the center that holds it on. I have one car where for some reason this loosened up. Perhaps that car had a transmission rebuild at some point. If the yoke is not tight you'll get vibrations in the drive line.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

The manual only covers a propeller shaft replacement, nothing about the flex disc directly, as mentioned.
It seems to me the bolts go in from the middle, out.

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83 SD

84 CD

I've just installed Febi replacements on my prop shaft and the instructions that came with the new parts said that the protruding bits of the disk need to fit into the recesses of the shaft and that the bolt heads should be facing forward - in the forward driving direction of the car. (I haven't actually got the shaft on the car so I don't know if it fits on easily this way just yet)

I guess if you buy some new disks you'll find similar instructions in the box.