Category = Facepalm.... Final Drive Version

[Twisties]

So, I had the outer seal to replace. Apparently I caught the housing of the FD with my drill when drilling the old seal. It's a pretty good ream and runs the depth of the seal seating surface. I went ahead and seated the new seal. No leak at rest, but leaks profusely when ridden.

 

So, do I just order a new FD? Any idea where I could get one used? Or is there a cost effective way to fill the void?

[dirtrider]

Evening Jan

 

Without seeing the damage it is difficult to tell you exactly what to do but unless the damage is very sever I would imagine you could seat a new seal & use some gasket sealer in the damaged area.

 

There are some mighty good gap filing gasket makers/gasket sealers in the automotive world now.

 

 

[mneblett]

D.R. -- how's about *judicious* use of JB Weld, followed by sanding to provide a smooth surface?

 

I'm thinking that approach is a permanent fix, i.e., no need to remember/deal with sealant every time (hopefully infrequently!) the seal is replaced.

[dirtrider]

Evening Mark

 

That would probably work but seems like a lot of work. Just have to be very careful that no sanding grit or sanding dust gets into the final drive bearing as there would be no seal there to stop grip intrusion. Also wouldn't want to sand or abrade the hollow axle in any way.

[Jim VonBaden]

Being that the sealing surface is damaged, you may get a seal, for a while, but it is not a permanent fix. Best to find a FD with a bad bearing and use the parts from both to fix it.

 

Jim

[Twisties]

D.R. -- how's about *judicious* use of JB Weld, followed by sanding to provide a smooth surface?

 

I'm thinking that approach is a permanent fix, i.e., no need to remember/deal with sealant every time (hopefully infrequently!) the seal is replaced.

 

I had actually been thinking to clean it up real good, then place some jb weld, then seat the seal before the jb weld sets up. Or alternatively, to clean it up real good, seat the seal, then try to inject the jb weld into the gap.

 

I can see potential issues with each approach, however. Gasket seal maker may be a better option.

[dirtrider]

Morning Jan

 

Yes, seeing as the seal SEATING area is damaged & not the seal SEALING surface then any of the good anaerobic sealers (gasket makers) should work great, not cause future seal removal issues, & form a lasting seal.

 

The beauty of anaerobic sealers is they go in soft & allow normal parts assembly & fitment, easily allow overflow to be wiped up with no remaining goop showing, don't cause issues if some gets into the gear chamber or bearings.

 

Anaerobic sealers only harden up with lack of oxygen (air) so they basically only harden in the areas that are closed off (like between the seal & the final drive seal bore)

 

The only thing that you need to be concerned with is size of gap so you can get the correct anaerobic sealer (if you have a .030" gap you don't want to use a .010" anaerobic sealer as it will take ages to harden in the damaged area gap.

 

Just make darn sure that you have both the seal & the seal bore in the final drive squeaky clean so the anaerobic sealer (gasket maker) adheres to both sides. Then ONLY use the sealer at the damaged area & just a little on each side of damage. If you use it too far around the seal that will make future seal removal more difficult.

 

If the damaged gap is large (like .035" plus) then you can try the anaerobic sealer but if it doesn't work then you might have to go with Mark's JB Weld suggestion.

 

If you go with the JB Weld (or Devcon) you might be able to use a little paste wax on the seal OD (only in the damaged area) then put a little JB Weld (or Devcon) in the drill damaged area, then drive the seal in (no sanding or machining needed this way). The paste wax should allow future seal removal if necessary. Again, make darn sure the seal bore is squeaky clean in the repair area.

[Twisties]

[Twisties]

I have Permatex red RTV on hand. Will that be suitable? As you point out, this is a seating surface. I am not sure why the new seal leaked? Is there any trick to seating the new seal correctly? Should I be dressing it with oil or anything before seating it? How do you know it's fully seated?

 

The other damaged spots are just to where the circlip sits. They don't go deep like the one bore just above 3 O'clock.

[dirtrider]

Evening JAn

 

RTV will probably stop it for a while but that isn't a trusted secure repair.

 

I really can't tell how much you damaged in the above picture (it doesn't look good but not enough definition to tell exactly)

 

Can you post some higher definition & better focused pictures from straight on & at slight angles?

[Skywagon]

for what it's worth. I poked a hole in a rim on my jeep. It was on the inside and the hole was about the circumference of a pencil. It drained the tire in about 30 seconds....

 

JB Weld overnight. 7 years later after selling jeep it never let go. If you use it get it the way you want it as sanding not likely. It gets really hard.

 

Ive also used products like Permatex Liquid Metal fill..comes in a tube.

 

[Twisties]

Had to break out the real camera and a macro lens.

 

 

Slight angle

 

 

Straight on

[eddd]

 

One thing to keep in mind about JB Weld...the "Steel" part of the two part product actually contains super fine steel which makes it even more important to keep residue from grinding and filing from contaminating any areas where this could become an issue.

[dirtrider]

Afternoon Jan

 

 

For some reason there still isn't enough detail to tell you anything conclusive.

 

Are you using a flash? If so try turning the flash off & trying different lighting into the damaged area.

 

The picture makes it look real bad (like too large of a gap to effectively seal long term using gasket maker, even large gap gasket maker). But the picture is not telling me the full detail of the damage.

 

Can to tell us how that happened (did you try drilling between the seal OD & the final drive housing hole ID?

 

You might have to use some Devcon (or even JB Weld) in that damaged area, then seat the seal with the Devcon (or JB Weld) still soft. Probably also have to put a light coat of Devcon/or/JB Weld on the seal OD (only in the damaged area).

 

That will make future seal removal more difficult but should seal the leak & you won't get any sanding debris into the bearing & inner drive that way.

 

 

 

 

[Twisties]

Thanks DR, and everyone. I'm going to try the JB Weld. I figure if the seal lasts me another 50-60k miles that is pretty much lifetime for this bike, or I'll replace the FD then. The alternative it to replace it now. Might as well try to get some more miles out of this one.

 

Should I be putting some grease in/on this seal before seating it?

[Jim VonBaden]

After seeing the photos I have to agree with DR. It looks like you could seal it without making the seal permanent. You just need to use the correct product.

 

Jim

[Twisties]

After seeing the photos I have to agree with DR. It looks like you could seal it without making the seal permanent. You just need to use the correct product.

 

Jim

 

What product?

[dirtrider]

Thanks DR, and everyone. I'm going to try the JB Weld. I figure if the seal lasts me another 50-60k miles that is pretty much lifetime for this bike, or I'll replace the FD then. The alternative it to replace it now. Might as well try to get some more miles out of this one.

 

Should I be putting some grease in/on this seal before seating it?

 

Evening Jan

 

I don't believe I would as those damaged areas look pretty deep, you want the JB to adhere to both the seal & the F/D housing to keep the repaired area from leaking in the future. (you could still get the seal out in the future as long as you ONLY put the JB in damaged area).

 

Just be darn sure that you clean the seal & the F/D seal bore to be squeaky clean (no oil present), then dab some JB in the final drive damaged spots & put a thin film of JB on the seal (in the damaged area only).

 

Probably put bike on center stand overnight before cleaning & installing the seal so any oil runs away from the seal seating area. (again it must be real clean to have the JB adhere to the seal & drive seal bore)

 

Added: Don't put too much JB in the F/D seal bore or on the seal OD, you don't want the JB running down into the bearing.

 

I think if I was making that repair I would lay the bike over on the L/H cylinder head on a folded blanket, then put a light coat of JB (actually I would probably use Devcon myself) on the seal OD in the area that is going to be in the repair area.

 

Then put a light coat in the final drive seal bore damaged spots.

 

Then drive the seal in.

 

Then use a toothpick & work some more JB into the damaged spots (between seal & F/D bore ) just push the JB down into the gaps using a tooth pick.

 

JB gets kind of runny just as it starts to set up so unless the bike is laying on it's side it might run out of the damaged area as it sets up.

 

 

[Twisties]

Thanks for all the help!

 

The seal is set. I'll tell you the results tomorrow.

 

 

[Twisties]

After a short ride, all seems fine.

[Twisties]

Well, It went about 250 miles dry as a bone, then seeped just a hint... Next day rode dry, then seeped a hair again. Third day worsened, but made it home without a major leak.

 

I guess this FD is toast. Just got a quote for a new one at $2080. Beyond our classifieds here, where I have a WTB pending, any thoughts on finding a used one or other sources for new?

 

 

[Guest Kakugo]

Well, It went about 250 miles dry as a bone, then seeped just a hint... Next day rode dry, then seeped a hair again. Third day worsened, but made it home without a major leak.

 

I guess this FD is toast. Just got a quote for a new one at $2080. Beyond our classifieds here, where I have a WTB pending, any thoughts on finding a used one or other sources for new?

 

 

These things are getting harder to come by than hen teeth.

There's presently a full swingarm/final drive/rear brake rotor on eBay.de. At 600€, it's a good bargain, though it comes from a Camhead and I am not 100% sure it's a direct fit.

There a few others around, but they come from authorities bikes and hence they have a shorter gear ratio.

[Twisties]

Looks like the part number is the same on the fiche at MAX BMW. Hmmmm.....

[Twisties]

I can't read the German... I gather that is from a 2012 RT with 5100 km on it. Then there is a bunch of other stuff I can't figure out. Looks like the exchange rate is almost even. $671. Can't tell what shipping might be. Can't really interpret the seller rating, but I think this is a private party with no history of sales?

 

Any help appreciated!

[MikeB60]

My Deutsch is rusty but here are the high points.

 

He has sold items in the past but not in the past 12 months. The auction is open for 7 more days. You will need to contact him regarding shipping cost but he will ship to the USA.

 

Its in good condition with no scratches or other issues.

Contact the seller via email with questions.

Functions as designed.

Works on other models.

 

 

[Twisties]

Thanks!

[Twisties]

I got one domestically on ebay.

 

Thanks!

[Heck]

Aw Jan....Just go down and buy a new bike.....

[Twisties]

Aw Jan....Just go down and buy a new bike.....

 

About ready to.... :-)