Final Drive Surgery with Pics

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motoleo
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Re: Final Drive Surgery with Pics

Post by motoleo » Wed Sep 18, 2013 8:21 am

BinDerSmokDat wrote:ReCycled just left...

:party: The FD is assembled and the case bolted back up! :party:

I'm exhausted. I'll get a few new pics up tomorrow.

Big, big thanks to Dave. He was a huge help.
He's still be driving home as I post his, he left looking more than a little tired.
Nice Job! :boogie: Glad you got it done in time to get on the road for this weekend. Now I know who to call if I have trouble with mine.
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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Wed Sep 18, 2013 8:28 am

motoleo wrote: Now I know who to call if I have trouble with mine.
Yeah...

Dave! :lol:

motoleo
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Re: Final Drive Surgery with Pics

Post by motoleo » Wed Sep 18, 2013 8:39 am

BinDerSmokDat wrote:
motoleo wrote: Now I know who to call if I have trouble with mine.
Yeah...

Dave! :lol:
2 heads are better than 1!
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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Wed Sep 18, 2013 8:58 am

OK as I'm going through my pics, there is some stuff I didn't post yet and is out of order.

New pinion seal, with old pinion seal (spring fell out) and pinion bearing nut...


Image


New inner pinion race. There is a slight bevel at the bottom edge. The bevel goes on the tip, the flat edge against the teeth.
Set the race on a hard flat surface and tap the pinion in.


Image

Image

Image


Next place the pinion in the freezer with your Jimmy Dean sausage sammiches.
In the meantime, set the 3304 bearing on a top of a hottish location.
Remember the stock bearings have polymer races, don't get them too hot.
I set mine on top of my bench light, which was reading about 200F. Leave both there for about 15 minutes.
Then with gloves, place the hot bearing on a vice so the vice jaws support the inner race.
Slip the pinion shaft into the bearing. Done this way, minimal tapping should be required to seat it.


Image

Image

Next is the ring gear. It slips on the splined hub easily, but once on it doesn't move, so you have to put it on with the holes perfectly aligned.
If you put the ring gear on and it doesn't line up, just invert it and tap the splines on the bench, the ring will pop off.
Lather, rinse, repeat until the holes line up.

Image

Image

Install the bolts with red loctite...

Image

There was some discussion about installing the bolts with the flat sides towards the edge.
I think that is a hold over from the metal clip days as far as the stock bolts (12mm heads) are concerned.
The bolt heads easily clear the outer bearing race, whether the corners or the flats are oriented towards the edge.
The aftermarket bolts which have 13mm heads also clear the race, but with slightly less clearance.
We assembled mine with 5 of the 8 bolts not aligned with the edge towards the race and it wasn't a problem.
But the anal retentive side of me later realigned them with the flats towards the race. :lol:

Here is the pinion and drive shaft slipped together, the outer bearing race and needles installed on the pinion. The old inner race is visible lower right. Note it is darker from lots of heat applied to remove it.
It was really an exercise in futility, because there was no way I was going to reuse it once I saw how much force and heat was used to remove it.
If you are replacing the pinion gear, replace the pinion bearing, don't even bother trying to remove the old inner race.

Image

Here is the gear set-up compound...

Image

Here is the mesh engagement pattern on the ring gear...looks pretty good.

Image

And here is what the pinion gear looks like. I re-used the stock shim on the pinion gear.

Image

I don't have pics from the rest of the final assembly.
If someone wants to use the pics and organize them in order, be my guest.
Again, I'd like to thank all the little people...

Herve Villechaize
Verne Troyer
Joe C.

Because let's face it, midgets are funny.

I'd also like to thank...
Billy G for his excellent site (without which I wouldn't even have attempted this rebuild)
ReCycled for his help, moral support and level headed words when I get impatient and just want to wail on it with a hammer.
And all the rest of you mugs for the encouraging words and suggestions.

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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Wed Sep 18, 2013 9:08 am

One other thing. Billy G's site mentions that the pinion needle bearing is 28 needles and the splined hub needle bearing is 49 needles.
On my bike I had 29 and 50 needles respectively.
The "new" replacement pinion needle bearing had 28.

The bearings were apparently upgraded with an extra needle at some point.
The outside fit dimensions are otherwise the same.
If you feel you absolutely need the extra needles, make sure you are ordering from a new parts list.
And if ordering from one of the big parts suppliers who may have stock sitting for a few years, verify with them that you are getting the new bearing and not the older equivalent.

I personally don't think it's a big issue, as the needles and inner races dimensions are appropriate for the number of needles.
There is no "gap" that the 29th needle fills; both bearings assemble with the needles properly spaced inside their respective races.

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Re: Final Drive Surgery with Pics

Post by Bryan Wilson » Wed Sep 18, 2013 9:52 am

Terrific post and photos You have great patience to tackle re-build and document the whole thing ,followed it with great
interest. Iam worn out gotta have beer. Welldone :beerchug:
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Re: Final Drive Surgery with Pics

Post by rebelpacket » Wed Sep 18, 2013 10:11 am

Great thread!! :clap:

Lots of good info in here.
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Re: Final Drive Surgery with Pics

Post by Albuquralque » Wed Sep 18, 2013 10:20 am

Great write up and pics! Thanks BDSD! :boogie:

Now keep us posted on how it is when you ride.
"Put a little gravel in your travel"

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Re: Final Drive Surgery with Pics

Post by Lokiboy » Wed Sep 18, 2013 11:00 am

When I get back in the states, I'll reconfigure the post and add to the "Best of" thread. Thanks for the great pictures and clarification on the mislabeled bearings in the parts book.
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Re: Final Drive Surgery with Pics

Post by MartyL » Wed Sep 18, 2013 11:40 am

Made into a sticky. Good info. Thanks for sharing! :)
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Wed Sep 18, 2013 1:12 pm

I'm actually in "Gobium mode" now...scouring sites for a blown 2WD FD to rebuild as a spare.

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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Thu Sep 26, 2013 8:57 am

Hey guys just a little update...

I bolted things up, filled with oil and then did what every good final drive break-in requires...
I rode the Jersey Devil Hunt off-road for two days, plus road miles there and back...maybe a few hundred miles total. :D

Here is the drain plug on the first change after the rebuild right after I got back form the JDH...

Image

And here was my first FD change when the bike only had 600km on the clock...

Image

They look comparable. I'll keep an eye on it. I've always changed the FD at 2500km or sooner when dunked.
My initial FD issue was stress, not lubrication related, so I don't see any need to change things.

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Re: Final Drive Surgery with Pics

Post by Mr Wazzock » Thu Feb 23, 2017 5:56 pm

BinDerSmokDat wrote:I picked up these at Fastenal while I was ordering new bolts. :D A lifetime supply!
Image

Thanks for this. Silly service manual seems to omit to mention what size the washers are...


Image
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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Sat May 11, 2019 9:59 pm

So blew my another FD today.
Got it apart, it ate three teeth on the ring gear this time.

I was going through a slick muddy patch that was the bypass around a deeper hole, then dropped of a "ledge" onto the sandy trail. When I say ledge, it couldn't have been more than a 3-4" drop with a root forming the lip of th edge between the mud and the sand trail.

I had the revs up a little during the mud and I guess when the tire caught traction it popped. The teeth didn't come off whole in big pieces like last time, they just crumbled, nothing bigger than about 3/8"-1/2". That is ironic because the first FD blew under more dramatic circumstances in 2WD. Today I was just in 1WD, in fact was in 1WD all day before this happened.

I stopped immediately because I knew what it was. It's an older FD I picked up on Ebay, maybe an 06-07. I was able to get hold of Terry and parts are shipping Monday.

I have the original 2010 FD I rebuilt in this post, but the 2WD output bearing fell out last year and I never fixed it. So I think replacing that bearing is the way to go to get up and running quickly. I'll get some pics up tomorrow.

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BinDerSmokDat
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Re: Final Drive Surgery with Pics

Post by BinDerSmokDat » Wed May 15, 2019 9:36 am

I've been busy so not many pics, here is a picture of the new damage.
You can see it took out three teeth.
This is unusual considering the low speeds and load involved.
I'm guess something stressed those teeth at some point and they just finally gave away.
I didn't get pics of the broken teeth but the pieces were much smaller than last time.
It could be metallurgy, as this was a 2005 FD vs. my 2010 last time.

I also wondered if the towing had anything to do with it.
The last time I blew the FD I rode down a mountain trail about a 1/4 mile before stopping and being towed out on a trailer.
This time I stopped immediately after hearing the clunk and put the rear wheel bearing cap over the FD splines and reinstalled the wheel before being towed out by another bike. This in theory allows for the rear wheel to be freewheeling, but I imagine there is still some spin imparted to the splines that could spin the FD a little.
I didn't look down while being towed to see if there was enough drag that the engine drive shaft was spinning with the FD.

There was a tiny piece of tooth wedged into an aluminum case web at the bottom on the 2005.
This is the same spot there was a scrape on my 2010. So in both cases teeth material got pushed around in the lower part of the case after the Big Bang.

The bike has currently got the 2005 driveshaft with the doughnut at the rear.
My quick fix will be to throw a driven hub bearing into my 2010 FD and then swap in the 2005 yoke/nut so I don't have to pull the swingarm.
This means no fiddling with gear lash or shimming.

When I get my parts from Terry, I'll build out the 2005 unit to 2010 parts specs so I can swap them almost as simply as wheels if needed.
I think the only differences between the two years are...
  • The yoke internal sealed diameter and driveshaft configuration.
  • A change to the 2WD throwout arm and interlock, which includes another seal change.


The 2WD interlock change doesn't actually cause any problems with swapping in and out whole drives.
The only problem there is the seal is the old odd Russian size, not a standard size like the new.
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