I need new Fork Seals!

[Julio A.]

I need to replace my fork seals since the front forks on my R65 is already leaking badly. Since I cannot wait for the two week waiting time for an OEM part to arrive, I will be shopping for a new part tomorrow.

Since I cannot just remove the old seals and put it back when I cannot find a replacement, I can only tell the inner diameter based on the size of the fork tubes itself. Does anyone have a spare part lying around to tell me what the correct inner and outer diameter of the fork seal is?  

My summer break project is already having good progress, I finished most of the rear end work today such as the swingarm alignment, new rear tires and a new break shoe and finished having the valves properly adjusted.  I'm moving on to the front end of the bike; more work needs to be done there.  

[Barry]

Julio

46mm OD 36mm ID

I had an old seal in the garage.

[Bob_Roller]

You may also need an o-ring for each fork cap .

There are aluminum washers under the bolt head at the bottom of the fork that hold the internal damper in place, they act as seals as well, so if they look a bit beat-up, may be a good idea to replace these as well .

[montmil]

Julio, I was about to answer your fork seal question when another tornadic-like wind, rain and hail event blew through town and my internet service just now came back on line.

The fork seals for your scooter are 36mm x 46mm x 7.3/8.8mm.

Besides the bits mentioned above, new felts in the rubber caps atop the fork lowers are a good idea, if available. Clean out the interior of the fork lowers with a solvent to get rid of the gunky sludge that seems to collect.

Monte

[nhmaf]

+1 on replacing those cheap aluminum 'crush' washers that you will find at the bottom end of the fork lowers under the big allen-head bolts.   Once I tried to re-use them by cleaning them up and flipping them around, and one of them still leaked once I started hitting bumpy roads.  The oil from that fork leg all leaked out over the course of a 40 mile ride and soaked the brake rotor on that side, which of course contaminated the pads and greatly reduced braking.   Had alot of extra work to do and new pads to buy for the sake of the false economy of re-using a 10 cent washer.    IF you cannot find the "official" aluminum  washer, a similar copper washer can also work.  

[Julio A.]

Finding the right pair of oil seals was quite a challenge; took me my own version of the amazing race around Metro Manila hardware stores to find it.  I'll be taking it apart tomorrow.  Is there any special instructions or steps I should be aware of?

BTW, The aluminum washer, It would take me a miracle to find a similar one lying around. Does anyone also know the dimension of that washer?
 

[Barry]

Here's one thread on changing the seals. A search should throw up a few more.
http://www.bmwr65.org/cgi-bin/yabb2/YaBB.pl?num=1290745869/1#1

If you are really stuck on finding the aluminium sealing washers they might be re-usable after annealing but you have to be very very careful not to melt them. The usual trick is to mark the aluminum with a bar of soap and heat gently until the soap turns black. The small drain plug washers are particularly difficult to anneal without melting.

[Yikes]

The washers at the bottom of the forks are the same as those used on the drain and fill plugs on the drive shaft.  BMW Part #07119963130 and they're 12 x 15.5.  At least on my '82.  Looks to be different on the '85 and up monos, but should be good on your '81. [smiley=bmw_smiley.gif]

[Julio A.]

Ugh. It took me the whole day to do the job and i'm not even done yet. I'm gonna sleep now. My finger tips are numb and my knees feel like jelly.

I have accomplished the FF today:
Replaced all fork seals
New fork oil
Re-tapped stripped threads on triple clamps
installed new front tires

But new problems appeared like:
Leaking final drive oil(I just installed new brake shoes yesterday   )
Odometer mileage not moving
My DIY kill switch fix finally failed.
Broken connector tabs on front signal light

[Bob_Roller]

There are o-rings on the camshaft that moves the brake shoes, they are known to go bad and start leaking final drive oil into the brake area .

The odometers are also another problem area, gears start slipping on their respective shafts and finally quit working .

[Vegasrandall]

Anybody got a good link to a exploded diagram of the forks?

[Barry]

All the online parts fiches have them. Here's one example

http://www.maxbmwmotorcycles.com/fiche/ShowImage.aspx?image=Diagrams/B0000575.png&rnd=17529292

Here's 3 of the online parts fiches that I'm aware of

http://www.maxbmwmotorcycles.com/fiche/fiche.asp
http://www.ascycles.com/illustrated_parts_catalog_main.aspx
http://www.realoem.com/bmw/select.do?kind=M&arch=1/