Changing oil in final drive unit.

I was able to change mine today as well. Using some PVC pipe to make my wrench longer did the trick to loosen those tight bolts.

Just like BassCliff's experience documented on his web site, I too had a little oil spill out of the fill hole when I first removed it, indicating that it was a bit over filled. I put the new oil in there till it spilled out of the fill hole, then waited a few minutes until it was level with the fill hole and nothing was coming out anymore.

The new synthetic oil looks so much nicer than the gunk that came out of there.

- Brad

Nice work there Mr. radbrad! I appreciate you not getting offended at my feeble attempts at humor.

I change my gear oils (bevel/secondary gear case and find drive) at least once a year. If you're using synthetic gear oil then I think it's OK to go a little past the factory recommendation for the dino gear oils. The synthetic gear oils are designed to sit in the differentials of big rigs for 50,000 miles.

Hmmmm, this AMSOIL comparison may be interesting.
http://www.amsoil.com/lit/g2457.pdf


Thank you for your indulgence,

BassCliff

I was able to change mine today as well. Using some PVC pipe to make my wrench longer did the trick to loosen those tight bolts.

Just like BassCliff's experience documented on his web site, I too had a little oil spill out of the fill hole when I first removed it, indicating that it was a bit over filled. I put the new oil in there till it spilled out of the fill hole, then waited a few minutes until it was level with the fill hole and nothing was coming out anymore.

The new synthetic oil looks so much nicer than the gunk that came out of there.

- Brad

Make sure not to strip out the drain threads like I did. Lefty-Loosey. Good luck!

I seem to always have a little confusion on threaded parts that point down instead of up, like the fill hole. The first time I put the wrench on the plug, I had to think about it.

Quote from Twin Peaks: "Look, it's trying to think!"

It's probably just old age.

I now feel a little stupid asking that question about the drain plug. I could have dreamed that it wasn't there, I guess. I went out to the bike and there it was in plain site. I appreciate the information on the secondary too.

I can't get the fill hole loose on my bike. What do you think would happen if one never replaces the final drive oil?

You'll DIE!


Use your favorite bolt loosener (WD-40, PB Blaster, Deep Creep?), get a BIG, LONG box end wrench (or socket), then lefty loosey. That means pull the wrench toward the back of the bike to loosen it. Maybe you can fit a piece of pipe over the wrench to give you more leverage.




Thank you for your indulgence,

BassCliff

I can't get the fill hole loose on my bike. What do you think would happen if one never replaces the final drive oil?

[Steve]

Yeah, I Googled it.

Saw that web site right there at the top, but then there were several videos of you jumping your bike over a cliff, too.

Video 1

Video 2

Video 3

the list goes on ... :

.

I suppose you found that on "some guy's website"?

.

Indeed.

Just Google "bikecliff" and see what's on top.

I wish that guy would learn how to use menus on his webpage.


Thank you for your indulgence,

BassCliff

Make sure not to strip out the drain threads like I did. Lefty-Loosey. Good luck!

[Steve]

HI Mr. mixongw,

For your perusal: ...

I suppose you found that on "some guy's website"?

.

HI Mr. mixongw,

For your perusal:

Secondary Gear Oil Change

Note: I had the gear oil too high in the original procedure but made note of the correct level in the addendum.

Final Drive Unit Oil Change

The crush washers for the drain and fill plugs are mentioned in the addendum of the secondary gear oil guide.


Thank you for your indulgence,

BassCliff

[duaneage]

Yeah, just fill it up to the point just before it overflows.

I add the recommended amount from the manual using a measuring cup.

[bwringer]

If you're talking about the secondary gear housing on the engine (850+ shafties), then here ya go:



Remove all three plugs to drain, replace the drain plug at the bottom, then fill slowly just until gear oil starts to come out the level plug. More is not better here. Replace the level plug and the fill plug.

If you're talking about the final drive back at the rear wheel, then it's the big obvious drain plug on the bottom. Fill just until gear oil reaches the bottom of the fill plug threads. Again, more is not better -- gear oil expands significantly in use.

The manual calls for 90W gear oil which is difficult to find. Any GL-5 gear oil in the same range will work fine (75W-90, 80W-90, 85W-90, etc.) As long as it's marked "hypoid" somewhere and is about the same thickness it'll work.

... Don't overfill it, that can cause big problems.

Yeah, just fill it up to the point just before it overflows.

[duaneage]

Should have a magnet built in, clean the fuzz off it.

Don't overfill it, that can cause big problems.