YM 2020D - Front Axle Leak - Gasket part number needed

Scotty Dive · 2025-11-09T10:39:18-0500

I have been limping along with this leak and have taken it apart about 6 times....what the old saying??? the definition of crazy is doing the same thing over and over again expecting a different result? I installed a new gasket /oil seal where it is leaking from. Everything looks solid to me. some wear on the mating surfaces but cant imagine the gasket is defective especially since its leaking from the same place as the first one. The seal is the TCS 115 - 145 13.5. (Size: 115mm ID x 145mm OD x 13.5mm thick). Oil Seal, TC-115-145-13.5. The seal sits good and tight onto the lower housing - I have to admit it looked like the gasket wasn't sitting perfectly so there could have been some debris keeping it proud and leaking from there. What does concern me is the inner part of the gasket is just snug enough on the upper housing to not fall off, but there has to be movement when the hub makes a turn to left or right. You can see in the images that is shows a slight groove of wear. Wonder of this is the problem? Love another couple sets of eyes on this to see if I am missing something

repete · 2025-11-09T10:54:11-0500

I chased leaks on the 2550 years ago and eventually found I had a crack in the the outer bevel gear case. My fault for heavy loads and reversed wheels putting all the load on the outer gear case.
Replaced the $500 case, returned the wheels to the "narrow" position and never looked back for probably 3000 hours. Still a daily driver at 6700 hours.

If you reassemble it, and the leak continues, put some UV dye in your axle and with a detection light monitor for the source.

bmaverick · 2025-11-09T11:31:35-0500

repete said:
I chased leaks on the 2550 years ago and eventually found I had a crack in the the outer bevel gear case. My fault for heavy loads and reversed wheels putting all the load on the outer gear case.
Replaced the $500 case, returned the wheels to the "narrow" position and never looked back for probably 3000 hours. Still a daily driver at 6700 hours.

If you reassemble it, and the leak continues, put some UV dye in your axle and with a detection light monitor for the source.

@Scotty Dive
These vintage machines could have hairline cracks where you are not seeing things. The surface rust could be hiding this fact.

I would cut-out a round disc of cardboard, lay it flat over the bevel gears, then wire wheel clean all of the surface rust. Then come back with an emery cloth to polish the surface clean.

Shop-vac out all of the particles, pull out the cardboard, shop-vac once again.

Now do the mating parts too. Keeping things clean as you go.

With material gone by a hundredth or thousand, you might need to make a gasket shim.

Leaks can also happen if you are overfilling. The top bevel gear sitting more vertical should splash up the lube oil/grease. Look at a few of the YM service manuals in the 4WD section to grasp the fill levels for these axles.

As an FYI, the YTOG is soon to release the largest service manual yet, the YM336. This is 4X larger than any of the other SM to date. So many details applicable to the other models of domestic and gray machines.

careyo63 · 2025-11-09T11:59:56-0500

YM2000 I have a collar that has a small leak. When the Seal did go bad I found that out. Pitted not a Scratch. My gear puller I wasn't able to extend the arms far enough to remove the Pressed on Collar. Hrs of use a Tsp. shows upon the tires rim. So I'm don't even worry about it! Old machinery is typical.

AaronM · 2025-11-09T13:16:38-0500

Those grooves where the seal rides can definitely cause a leak. You can get a repair sleeve that presses on there and will give you a nice new surface for the seal to ride on. We have done that MANY times and works great.