Oil/transmission leak?

[unibober]

Well I received my shift linkage from Justin today and it install with little fuss.  Quite a nice piece!  Thanks Justin!  So as I am installing the part I noticed a bit of oil on the base of the cradle that the shift part that goes into the transmission.  I thought I had seen a post about replacing a seal in there, but cant find it. Anybody know what Im referring to?  :-?

[Bob_Roller]

It's the shift shaft seal .

You need to remove the allen head bolt that holds the shifter arm to the transmission remove the shift arm, then you can see the seal .

It's a 20 minute job to replace it .

[unibober]

Im assuming the transmission oil will need to be drained. Is there a cheaper source than realoem for the part?

[unibober]

Update...found that my neutral switch is leaking. Not around the outside, but around the plastic prong piece. Looks like a bear to get to. Crap.

[Rob Valdez 79 R65]

Update...found that my neutral switch is leaking. Not around the outside, but around the plastic prong piece. Looks like a bear to get to. Crap.

Two ways to get to it - both are a pain.

First is to slide the transmission back as far as it will go.  You may not need to disturb the swingarm pivots - I don't know.

The other method is to support the rear of the engine, and pull the rear engine mount out.  Then, with a big screwdriver, remove the large spacer that looks like it is part of the engine, esp. if it is dirty.
That should give you the room you need.
To reinstall the spacer, you will probably need to put it in the freezer for a while.  I think I've read of some shaving a little metal off one end, as well.

I prefer the first, and I would just pull the transmission and do a proper servicing of the splines and the swingarm bearings if it hadn't been done in a while.

[unibober]

Thanks Rob. I think I will go with the first.  Talked to my buddy who sold me the bike and he had no recall of the splines being done.  Kill 2 birds kinda thing... Thanks again.

[Rob Valdez 79 R65]

Don't forget your 4 new driveshaft bolts.  (correct, shorter length - M8x1x13mm)

You might want to give Hucky in Florida a try.  He has a less expensive alternative switch, but I chickened out and bought the OEM one.  He says the aftermarket is brass, so you want to be careful not to overtighten.  $29.50 vs $39.50.

http://www.bmwhucky.com/010023.html

[nhmaf]

And, you can go to the wiki development subforum and the latest thread I've posted a pdf copy of my article with pics on replacing the clutch - should help you with removing the transmission and lubing the splines..

[unibober]

Sounds good.  Trying to make a list of parts I may replace while Im in there.  Scary.

[montmil]

Motobins has your parts, too.

Shift shaft seal, Part# 42500  
http://www.motobins.co.uk/bmw-parts.php?model=R%20Series%202%20valve%20Twin
Confirm your seal's correct size before ordering. Motobins lists 24x16x7 and Huckys is 26x16x7. ??
Could be a typo...   Local bearing supply shops may also be a resource for the seals. Know your prices first.

Neutral switch, Part# 76700A (repop) or #76700 OEM for about twice the price. $20.00 vs $34.00. I run the Italian-made repop. It really doesn't matter if the switch body is brass or steel. The very real concern is stripping the transmission case threads. Don't forget to use a new aluminum crush washer on refit.

I put a small bevel on each end of the honkin' big aluminum spacer and it went back with a wee bit of cussin'. Freezing the pipe only makes your fingers cold! The bike's chassis draws the chill away much faster than you'll be able to get the damned pipe back in place.

A l-o-n-g, tapered line up drift is also helpful.

Huckys BMW is a good source, too. I've used him. His repop switch is $30.00 and OEM is $40.00.
http://www.bmwhucky.com/
A small outfit leaning towards the older slash series bikes, you'll need to email Hans your needs and he'll email back with availability, prices and shipping. Really nice gentleman, working off his kitchen table down in sunny Floida.

Monte

[Semper Gumby]

When you replace the shift shaft seal do not press the new seal home till it seats.  It will leak again in no time at all.
Before you install the seal look at the hole that the tranny case forms around the seal (that holds the outside of the seal).  The inner diameter of this hole has a taper to it.  The seal sould be pushed no farther than the inner end of the taper (so that the outside of the seal should be flush with the inner end of the taper).  This will position the lip of the seal correctly on a small taper next to the arm of the shifter shaft when you intall it next.  Be sure to grease the inner lip of the seal before you press in the shifter shaft.

Good luck.

[Ed Miller]

If you do replace the shifter seal like Semper G says, you don't have to drain the gearbox oil.  Just lean the bike up against something to the right, so that the shift seal is above the oil level.

[montmil]

Here's the shifter shaft seal dimensions and BMW part number as used on my 1981 R65:

26x16x7  -  BMW Part# 23 12 1 338 740

Monte

[unibober]

Thanks for all the advice. It helps me alot and hopefully will keep the gremlins at bay.

I decided to not tackle my splines until I talk with this fellow.http://www.chuckhousemotorsports.com/
He works on a friends beemer and comes highly recommended. Just glad there is a place like this somewhat close.

In saying that, I cheated in order to get to the neutral switch. Pulled the motor mount rod thingie (5 min and very lubed) and then gingerly pulled the long alloy spacer. Then had the switch in my face. Drained fluid, pulled switch, and found a very small amount of metal dust on the plug. Oh happy day!  Checked the switch and it had no continuity no matter how I tried and the fluid was beautiful. So now I sit and wait for the appropriate washers/switch as more and more riding buddies call and inquire why Im not out on the ride today.  Ahh...friends with new bikes.

Do have one question... Is all hypoid 80w oil the same? Reason I ask is that I have gallons of Yamaha Outboard marine gear oil that seems to be the same. Is this ok?

[Bob_Roller]

I think I'd use an automotive grade lubricant in the transmission .

Don't know enough about marine gear lube to say it would work or not .