Author Topic: Replacing flex discs W116  (Read 352 times)

Jan S

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Replacing flex discs W116
« on: 21 May 2021, 05:36 PM »
The next job this weekend is to replace the two flex discs incl. bolts, center bearing and rear transmission mount.

Question: which side of the disc should point to the front and which side to the rear? Does it matter which way it's installed?

Tips much appreciated.
1975-mod W116 450 SE with 6.9 engine

daantjie

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Re: Replacing flex discs W116
« Reply #1 on: 21 May 2021, 06:33 PM »
Most important here is that you install the raised metal section to engage with the flange on both the diff and the transmission output shaft as well the drive shaft flange on both ends, thus there is no "this way forward" as such, but you need to make sure that the disk engages the flange properly.  Here is a good posting from another site which explains clearly what I mean, look at first post as well as the pics they have, quite clear.  If you make sure for example that the "front" at the transmission end enganges the disk end correctly, then on the flip side of the disk it will be the inverse, so on the "back" now it will engage properly on the drive shaft flange, you will see what I mean once you have it correctly aligned:

http://www.peachparts.com/shopforum/tech-help/235575-flex-disc-orientation-safety-durability-issue.html

« Last Edit: 21 May 2021, 06:40 PM by daantjie »
Daniel
1977 450 SEL 6.9 - Astralsilber

Jan S

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Re: Replacing flex discs W116
« Reply #2 on: 22 May 2021, 10:47 AM »
Thanks, daantjie, much appreciated!

Yes, I'm aware of the "flange issue". Good to know that there is no "this way forward".

Disassembled the drive shaft, flex discs, center bearing, transmission mount today. Not difficult but took some time and important to keep an eye on safety.

The bearing/mount was toast, flex discs with some cracks (but fairly ok considering 46 yrs.). Will replace it all.
1975-mod W116 450 SE with 6.9 engine

Jan S

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Re: Replacing flex discs W116
« Reply #3 on: 01 June 2021, 02:05 PM »
The car is much smoother now, and the "rumbling" when lifting the foot from the pedal at speed is completely gone (probably from the toasted center bearing mount.

Love it!
1975-mod W116 450 SE with 6.9 engine