Ducati Monster Forum

Moto Board => Tech => Topic started by: rata911 on May 05, 2010, 03:08:52 AM

Title: 1994 M900 Cush drive rubber dampers - Quick question
Post by: rata911 on May 05, 2010, 03:08:52 AM
Hey guys,

just changed the cush drive rubbers on my 1994 M900 - those 16 year old OEM thingies were a PITA to get out, I tell ya...  >:(
The rubber is THAT blown so that on one damper I just pulled the inner ring and on another the inner ring plus the rubbber...leaving the outer rings in their seats  >:(  >:(

(http://img11.imageshack.us/img11/1249/26042010007a.th.jpg) (http://img11.imageshack.us/i/26042010007a.jpg/)(http://img11.imageshack.us/img11/5025/26042010006.th.jpg) (http://img11.imageshack.us/i/26042010006.jpg/)

Now that I've inserted new ones I'm curious: There's an inner and an outer ring, like on a bearing. The inner ring (for the chain wheel adapter bolts) is about 1 mm longer on each side than the outer ring. At the moment the outer ring of all 6 rubbers is completely inserted into its seat and the inner ring is lurking out for about 1 mm creating a gap of named length between the seats on the rim and the chain wheel adapter.

Question: Is that ok e.g. am I fine or do the inner rings have to be planar / align with the seats, the rim, actually?

Thx :)

[moto]
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: ducpainter on May 05, 2010, 03:16:36 AM
I had to replace some of mine and left the inner sticking out as you have yours.

It seems to work fine.

If you think about it it would be difficult to install the outer ring past flush with the wheel.
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: rata911 on May 07, 2010, 01:05:32 AM
Thx for the reply. I'll leave that way, I guess.

QuoteIf you think about it it would be difficult to install the outer ring past flush with the wheel.

Indeed. Either use a nut the *exact* size of a damper or hit the inner ring which I'd like avoid obviously.
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: Speeddog on May 07, 2010, 04:54:25 AM
You want the inner ring to be 'above' that surface of the hub, so that the sprocket carrier doesn't hit the hub.
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: Monsterlover on May 09, 2010, 11:15:53 AM
howd you get those out rings out (the old ones)?
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: ducpainter on May 09, 2010, 11:17:39 AM
Quote from: Monsterlover on May 09, 2010, 11:15:53 AM
howd you get those out rings out (the old ones)?
I used a die grinder with a small ball cutter and cut a groove so I could collapse it and pull it out.

If you're careful you just barely nick the wheel.
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: printman on May 09, 2010, 02:50:10 PM
Quote from: ducpainter on May 09, 2010, 11:17:39 AM
I used a die grinder with a small ball cutter and cut a groove so I could collapse it and pull it out.

If you're careful you just barely nick the wheel.


had to do the same thing. The whole time saying" I hope this is right, and don't mess this up."  Turned out alright though.
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: Monsterlover on May 09, 2010, 06:29:52 PM
I got them out intact.

I beat them out from the back side with a long punch (actually a 6" 3/8 drive socket extension that I twisted the socket end off of a while back)

the only casualty was a knuckle on my left hand.

It was a full on miss with the full rage of Thor behind a good sized ball peen hammer.

But hey, I saved like $70 bucks and swelling goes away

:D
Title: Re: 1994 M900 Cush drive rubber dampers - Quick question
Post by: rata911 on May 10, 2010, 01:26:33 AM
QuoteI used a die grinder with a small ball cutter and cut a groove so I could collapse it and pull it out.

I pulled them out with a "tool" that you can rebuild yourself easily. My extraction process didn't work for two of those buggers and I had to ... beat the crap out of them :P. But as you did I used a Dremel to cut a groove that serves as a predetermined breaking point, then several drift punches until I could grab them with a caliper and pulled them out.
Thank God I only had to do that with 2 of them, the others went out fine:

Quotehowd you get those out rings out (the old ones)?

Get a threaded bar (M10) of about 30 cm, a piece of pipe that has a bigger diameter than the dampers (40mm+ I guess it was) some nuts and some washers. Lock two nuts at one end of the threaded bar and insert it into the rubber dampers from behind (the brake's side of the wheel) together with a small washer that is a little bigger than the inner ring. On the other side put the piece of pipe over your damper seat (use tape to protect the wheel from scratches, if you like), put some washers on that and finally use another nut to put pressure on the dampers and finally pull them out. If you preheat your seats thoroughly (!) with a heat gun and let the dampers soak in WD40 overnight they should come out easily. Unfortunately, I wasn't that lucky twice, so I just pulled the inner stuff out because of the...rotten...rubber. Just imagine you already removed the piece of pipe and this was a complete damper and it should look like this:

(http://img11.imageshack.us/img11/5025/26042010006.jpg) (http://img11.imageshack.us/i/26042010006.jpg/)