B6200HST rear axle oil leak?

[PeterA]

I have a B6200HST which has given great service over the last 13 years. I have all relevant manuals. I have a significant oil leak from the rear axle area. It does not appear to be the PTO shaft seal, and it's not transmission fluid (which is clear, and my fluid level on the dipstick is good). The oil drips off the rear axle case directly below the PTO mechanism, and is yellowish in colour.

What is the most likely cause of this leak? Your help would be greatly appreciated.

 

[North Idaho Wolfman]

UMMM that's hydraulic fluid / transmission fluid, there is no other fluid in the back of the tractor.
The most likely canidate is the PTO cover, second most likely would be the axle cases.

 

[emac]

Clean the area with brake parts cleaner and try and find the source. My axle case (L3600) was leaking. It wasnt hard to fix. Just needed to be resealed.

 

[PeterA]

Thanks for your replies. I'll investigate further. I'm trying to avoid having to replace the gasket on the rear axle case. That looks like a big job, and like so much else with this track, I've never done it before (another first). I try to get it right the first time, as well as the second.

It has me a bit stumped, though, because the transmission fluid level on the dip stick is still showing good, which doesn't make sense given the amount of fluid leakage into the white tub (and the ground, before I noticed it).

 

[Dave_eng]

I have had good luck finding leaks using ultra violet light and a special dye.
Watch this video:
UV leak
Amazon sells these products and they are not expensive.
Just be certain to get a dye compatible with oil like this one. There are other dyes for antifreeze and the AC industry uses them all the time.
UV dye
Dave

 

[PeterA]

Thanks Dave. It seems to me that if excess transmission fluid is put into the machine, it will flow back out of the dip stick port, no where else. I ran the tractor for 20 minutes this morning, and not a drip escaped, as far as I can tell. And, the dip stick is still showing full. Hmmmm. I will have to try the UV light method.

 

[Russell King]

The whole case is full of several gallons of transmission fluid that will leak out of any mating surfaces.

The amount of fluid leaking did not appear to be a significant amount compared to what is in the case to cause the level to drop much.

How much is being leaked per day? May need more time to drop the level?

 

[North Idaho Wolfman]

There is a vent under the seat bracket that can purge fluid and make it look like an axle leak.

 

[PeterA]

Thanks to all of you for your assistance! I will monitor the transmission fluid, etc. carefully and report back any continuing issues. Best wishes. Peter

 

[PeterA]

A small leak continues. I believe this is a PTO gasket leak.

 

[N3BP]

Have you checked your PTO shaft for excessive play? I ran into a similar situation where my B7200 was leaking from the rear and couldn't see anything when it was parked. I'd run it then it started leaking again. When I moved the PTO shaft, it had enough play in it to leak between the seal and shaft. Replaced the bearings and that fixed it.

If you have to replace the gasket, use a little gray or black RTV along with the gasket. I couldn't get mine to seal properly with the gasket alone. You also want to replace the PTO seal at the same time. If you jack the rear end up as high as you safely can, you'll minimize fluid loss during the replacement process.