Center bearing rubber doughnut orientation

[wwheeler]

I have a question concerning the orientation of the driveshaft center bearing rubber doughnut. The doughnut (that's making me hungry!) presses inside the aluminum housing which of course mounts to the body pan. On my '68 W111, the doughnut can fit in two ways as the hole in the center is offset. The hole in the doughnuts with the earlier grease fitting style bearing was centered. The later ones are off center.

So the question is does the fatter section of the doughnut go torward the bottom or the top? In the manual 41-2/1, it shows a cross section of the center bearing assembly and it appears that the fat section is on the bottom side. No marking on the rubber piece that gives a clue. Any ideas?

In that same picture, they show the front shaft clamping nut and a rubber protective boot that slides over it. That nut in the picture appears to have a groove to hold the boot where as mine does not and is smooth. Do later clamping nuts have the retaining groove? The new MB boot I bought had a molded internal ring for that nut groove but I had to grind it off to keep the boot on. Anybody seen that?

Thanks!

[w113dude]

Wallace,

Here is the photo from BBB, it shows the fatter part of the donut being on the lower end, #4 is the donut.

Shaun

[Naj ✝︎]

In that same picture, they show the front shaft clamping nut and a rubber protective boot that slides over it. That nut in the picture appears to have a groove to hold the boot where as mine does not and is smooth. Do later clamping nuts have the retaining groove? The new MB boot I bought had a molded internal ring for that nut groove but I had to grind it off to keep the boot on. Anybody seen that?

Thanks!

This one is out of a W108.
Where did you buy the new boot from?

Naj

[wwheeler]

Thanks Shaun and Naj! I put the fat end at the bottom as well and am surprised there wasn't some kind of fool-proofing done on this. I recently saw someone's old center bearing and the doughnut was upside down according to the picture. That is what got me wondering.

I bought the boot #108 411 00 97 from the Classic Center here in the US. That is the groove I am talking about and mine doesn't have it. Same nut, just no groove. The groove design is an obvious improvement and was probably implemented later than my car. So the boot with a groove superceeded the non-groove boot design and that is what they are selling. That is not uncommon from my experience with superceeded part numbers and they usually require some modification. I ground the inner rubber radius and it fits OK. Not sure how long it will stay though. I took a picture and will post it tonight.

Thanks again for the help! 

[georgem]

Thats terrible - a donut thats lost its groove - hey man, it just won`t be able to chill out...........

[wwheeler]

As promised, here is a pic of the rubber doughnut installed in the aluminum center bearing housing. The fat part is on the bottom. As one of the members pointed out, this one doesn't have the hole for the grease fitting while the earlier "centered" rubber does have the grease fitting hole.

I also included a pic of the installed center bearing assembly with the rubber protective sleeve. It is stretched over the clamping nut. This doesn't have the groove, so I hope it stays on. You can see the notch at the bottom of the rubber housing where the grease fitting would go if I had one.

[erickmarciano]

I am doing this right now and i am a little confused
if I install As per Shawn picture i have a problem

On the transmision side

If the circlip 13 holding the bearing , faces the trans , then If I  install the # 8 protective cap . The top of the cap rides on the bearing circlip not the inside of bearing . Then I install # 11 circlip the whole does not sit right . Is this an error in the BBB ? It all fits better if the circlip of the bearing faces the diff and the protective cap #8 faces the trans.
Hope i am clear ??
One last thing any errors the the pictures of the BBB for the 4sp transmision?one bearing faces the wrong way.

Thanks for your help
Erick