Rear Drive

[MrRiden]

Had this bike dropped off and today I got a chance to look things over. It looks like the first order of business will be to fix the rear drive leak. I found a post on replacing the final drive seal and cover gasket. Particularly liked the beer can installation tip! I seem to recall removing the front wheel and tipping the bike to allow clearance to remove the rear wheel. Do I have this right or is there a simpler way.

[Bob_Roller]

Hi Rich !!
I put a think piece of plywood under the bike then put the bike on the center stand a lot less work than removing the front wheel .
You'll also need 2 o-rings for the brake camshaft .
I don't know what procedure you have, but you use the bolts that hold the cover on, to remove the cover, thread them into the threaded holes in the cover .
Also, the paper gasket only goes on one way .
To ease installation, I put the crown gear in the freezer and the cover in the sun to heat it up .

[georgesgiralt]

Hello !
Two things :
1) the old paper gasket is a PITA to remove/clean. So use a gasket remover to soften the glue and ease the removing.
2) as Barry said, heat is your ally. I use a electric gun (the thing that can go up to 600 °C if let alone...) you do not have to go that far, though.
If you have to remove the lip seal at the bottom of the bevel box, use heat to remove the inside bearing. It will fall out alone. Installation is in reverse. Box heated and bearing in the freezer.  NO HAMMER NEVER !
Have a nice day!

[Tony Smith]

Until this post, last entry was 6 years ago. Huh?

[georgesgiralt]

Hi Tony,
Is your computer date set correctly ?
the first post is stamped : Yesterday at 16:56:06 on my machine.

[Bob_Roller]

All the posts show Nov, 06, depending on which part of planet earth you reside on .

[Tony Smith]

Date Problem resolved

[mrclubike]

this   is the best way to remove the rear wheel

[MrRiden]

Ok, Going to go over the procedure for seal replacement a few more times, place an order for parts and purchase a nice heat gun. Something I've been meaning to add but until now the midday desert sun has sufficed. I'll update with questions and progress once I've assembled the kit. Thanks for the tips so far, nice to have someone lookin' over your shoulder.

[Tony Smith]

Motobins sell a rear drive rebuild kit at somewhat of a discount from buying the parts individually.

[MrRiden]

Motobins sell a rear drive rebuild kit at somewhat of a discount from buying the parts individually.

Yea I've been looking at their site and saw the nice set but on reading a few different posts it seems I'll need some tooling to get to the input seals, if I'm reading correctly. I'm also a bit confused on a  "seal behind the crown gear". Here's what I've got so far
REAR BRAKE CAM O-RING BMW: 07 11 9 906 328
FINAL DRIVE SEAL BMW: 33 12 3 004 343
FINAL DRIVE COVER PLATE GASKET BMW: 33 11 2 311 097
Can't quite figure that seal behind the crown (ring?) gear though.
Not so sure If I can get to the Input shaft seals but any how to's would sure be welcome.

[Bob_Roller]

You've got all the parts you'll need, the final drive seal is the one pressed into the cover, no seals behind the crown gear .

[Tony Smith]

Yea I've been looking at their site and saw the nice set but on reading a few different posts it seems I'll need some tooling to get to the input seals, if I'm reading correctly. .

You can't do the input seals without special tools, very few people, even BMW shops, have the tooling needed. you could do what nearly everybody else does and simply pack the drive shaft coupler area with as much grease as you can get in there.

FWIIW, here is the tooling you need to get the input bearing/seal out.

[georgesgiralt]

Hello !
If you plan to exchange the big lip one on the wheel side, you also have to change (IMHO) the lip seal sitting under the needle bearing opposite the wheel. For this you need to put the case inverted on a couple of 2x4 and heat the case. When sufficiently hot, the needle bearing will fall itself out. Then you'll see the lip seal.
The driving pinion has a lip seal on the castellated ring and a strange looking seal under the main nut.  If you remove the castellated nut, you'll have to put something to seal the threads when putting it back.
So in theory, you need 2 lip seal and a paper gasket for the crown side of the device and a lip seal and a strange plastic washer for the driving side of the drive.

[DadsR65]

Yea I've been looking at their site and saw the nice set but on reading a few different posts it seems I'll need some tooling to get to the input seals, if I'm reading correctly. .

You can't do the input seals without special tools, very few people, even BMW shops, have the tooling needed. you could do what nearly everybody else does and simply pack the drive shaft coupler area with as much grease as you can get in there.

FWIIW, here is the tooling you need to get the input bearing/seal out.

I found a way to disassemble the front of the FD without the pricey tools.  I needed to Helicoil a stripped drive shaft plug, so I took the nose of the FD apart.

Details here:

https://advrider.com/f/threads/new-airhead-project.1260761/page-3#post-33692161