Speedometer cable output shaft leak

[Chuck W.]

Chasing down a couple of annoying oil leaks on my CJ3B. One of the worst ones seems to be at the speedometer drive gear. Everything is tight, but I'm still getting a seep. I was trying to see if there is any type seal or O-ring in the driven gear sleeve before I take it out, but it appears not. Any fixes for this leak? Permatex on the sleeve threads?

[Rus Curtis]

Chuck,
I noticed you're getting some input on the g503 forum.  Hopefully, that tracks to a solution.  I did think of overfill or blocked passage ways.  The oil should be shared between the two gearboxes.

I've just never seen oil come out of the cable housing before, so I'm not sure.

There could be one test I can think of.  Fill both to the filler plugs.  Drive until you get that leak out the cable fitting.  Then remove the transfer case filler plug.  If the level is now above the filler plug, it may not be draining back to the transmission fast enough.

[Chuck W.]

Thanks, Rus.  One thing I have noticed today, it appears that the speedometer drive gear output is lower than the TC fill plug. I need to measure tomorrow to be sure, but it's either lower or on the same level. I may just need to drop the oil level in the TC slightly.

[SteveKfl]

If I may add my thought, check the opposite fill location first to see if it is still full, and then the suspect 'overfilled location'.  As Rus pointed out, there is supposed to be a drain back between the two halves.  Draining the 'fuller side' will still deprive the other half 'without proper drain back' and may not be a 'good fix'.

[Rus Curtis]

If I may add my thought, check the opposite fill location first to see if it is still full, and then the suspect 'overfilled location'.  As Rus pointed out, there is supposed to be a drain back between the two halves.  Draining the 'fuller side' will still deprive the other half 'without proper drain back' and may not be a 'good fix'.

This would be more thorough.  Yes, check both.

[Bob W]

Just a bit off topic but....
The normal transfer case fluid level is lower than the transmission fluid level. When the vehicle is driven forward, oil in the transfer case flies off the spinning gears into a cast slot in the transfer case and through a drilled hole where it enters the transmission. So, when driving down the road oil is constantly being "pumped" from the transfer case into the transmission. There is another drilled hole between the gearboxes at the transmission normal oil level. When the transfer case pumps enough oil into the transmission that it is "full" any additional oil drains by gravity back into the transfer case.