Changing Final Gear Oil

[ringadingh]

Thats how I found that mine was leaking. There was a wee bit of oil sweating by the 4 acorn nuts. When I loosened the 4 nuts 2-3 tablespoons leaked out that was sitting in there. I just went to the local bearing supplier and picked up the seal rather than go to the dealer, it was only $7.88for a Timken seal p/n 703019. the size is a 40x52x7. Just remember the lock collar that holds the seal is a reverse thread. I don't have the proper wrench to remove it, so I tapped it out with a punch.

Depending on what year your Nomad, it could have a different seal. I know they changed the rear gearcase design with the L4 models, which I believe was 2003. I suppose it's possible some sold in 2003 were L3's though. Anyhow, the L3 was the last model with the reverse-threaded collar. L4's went to a flanged retainer design.

[macmac]

I change mine when ever I change the engine oil. That 6+ ounces is a pissant in the snow of gear lube. On the side stand in my way because the level goes up when the oil is heated.

1 qt cold will rise 1/2 " hot! Now i know it doesn't hold 1 qt, and it is depending on the particular bike 6 to 8 ounces as some guys cram 8 ounces in the thinking more is 'better', but this is once case where more is far worse, and in time you will Drown the Seals. A once drowned seal will leak untill it is replaced....

I know this breaks all the rules as engine oil is level bike, and that works because when in a cornewr the oil flows to the other side of the bike, which it can't do in that gear box..

Like my engine I run Moble 1 full syn gear oil.

The hard part is getting the muffler out of the way to get the damn drain bolt out.

Cadd drops his rear end, while I loosen the head pipe nuts, and swing the muffer out a smidgen. V&H baggers... It works a little easier stock, since there are graphite gaskets that slip pretty easy.

I have less problems now since the first time, when I milled the drain plug SHORTER. I make a new gasket each time from copper. The same can be done in nylon, plastic so long as it is softer, and or good gasket paper.

I have copper on hand because I use copper as a 'cutting plate' for sterling silver, so I could just as easily make the 'crush washer' from sterling if I chose too.

[blowndodge]

macmac, how is that 1/2 inch rise measured? I would think that 1qt of cold oil in a long tube heated would "rise" higher than 1 qt of oil in a flat pan heated? Just thinking out loud...

Stock "baffelectomy" mufflers are nice for changing final gear oil..

Proportionally, the rise due to heat expansion (and lots of air entrainment from gear motion) might actually be higher in the Nomad gearcase, since it's surface to volume ratio of the oil is very low compared to something like a 3/4" ton Chevy pumpkin (which I think is where Mac was headed in his thinking.)

Definately any exact measurement of rise is dependent on the surface to volume ratio of the container.

[siderider]

I changed my rear end oil recently. I stood the bike up (it easy as I have a sidecar) and used the recommended oil. In about a week it started to leak. I then went to heavier oil and yep, it still leaks.

I always thought that there was something I did that caused it and now I know as it was overfilled. I will drain some out and try it again and thanks for the tip

[misunderstood]

Yeah, thanks for the discussion as I will be doing mine soon and wouldn't have known.