Mid Transmission Mystery Leak

[mmranch]

I've got a couple of hydraulic oil leaks and one is a bit of a mystery. One is a rear PTO shaft oil seal leak and the parts are coming, and that one is fairly simple. The other is more mysterious.


A while back, I split my tractor to repair an input shaft oil leak in the front section of the transmission. That repair went fine. But while I was dealing with that, I noticed a row of droplets on the bottom of the mid-section of the transmission in the vicinity of two drain plugs. I thought, 'OK... I've some leaky plugs!' so I re-did them with new sealant, etc. Well I was excited about my new clutch working great but the mid-section oil droplets were back immediately.

So I started to look closer. The PTO shaft leak basically comes straight down the back of the case. It is NOT migrating forward along the belly of the rear section... this is dry. The right side of the transmission is dry. The top of the transmission is dry (very easy to tell as there is a powder dry layer of dirt along the top with no oil stains whatever).

The left side of the transmission is dry except for the area around the mid-section. The fuel tank is sandwiched next to the mid-section and it's a pain to even get to the zone. There are 2 shifters that connect onto the left side of the mid-section. It is damp looking around these shifter areas... but doesn't appear super wet and there is a layer of dirt around that is not washed away. The shifter boots and bolts all look intact and nothing is out of place. The mid-section seems firmly attached and all mounting bolts are in place and are covered with thick paint and haven't moved that I can tell. The damp area also is over on the fuel tank beside. The tank has a thin layer of dirt so it's easy to see any dampness and it's only right next to the transmission dampness (it is not a fuel leak and the droplets aren't diesel).

I removed the transmission vent hose and blew it out with the air compressor and it was already clean and works fine. I have dried off the droplets from the bottom of the transmission and let it sit for days. The droplets don't seem to re-appear until after I've used the tractor. (When I park the tractor after snow plowing, the snow on the machine soaks the floor of my shop so I can't really tell about leaks until a day later after all the water has drained and dried, etc).

Also after had plowed the other day, I noticed a small stream of oil on the snow in several areas. I checked my previous input shaft leak repairs and that does not seem to be leaking. A stream type leak implies a stream... I see no leaks when I run the machine. Nothing... nada.

Just to work on the area, I will have to remove the backhoe, jack up the tractor, remove FEL frame mount (on that side), pump out the fuel tank and uninstall it, etc. to get to the area from underneath. Or I could remove the cab and get at it from the top! Loads of fun.


Have others seen problems in the mid-section area with shifters and such? (I know there have been problems with transmission vents getting plugged and then causing leaking but the vent is clear).


I need to install a camera on the bottom of the tractor so I can see what's happening underneath!

Thanks for any ideas!

 

[dougtrr2]

If you are getting streams of oil I would start looking an the hoses and piping. Could be that you have a split that only leaks under pressure, like when you actually raise the three point for example. I would start with wiping down everything and putting cardboard under it while it is parked. Maybe get a helper to activate controls while you safely watch from a slight distance, that is don't get underneath to watch and become a post on the Safety forum.

Doug in SW IA

 

[rScotty]

If you are getting streams of oil I would start looking an the hoses and piping. Could be that you have a split that only leaks under pressure, like when you actually raise the three point for example. I would start with wiping down everything and putting cardboard under it while it is parked. Maybe get a helper to activate controls while you safely watch from a slight distance, that is don't get underneath to watch and become a post on the Safety forum.

Doug in SW IA

I took a medium/low pressure electric power washer to the underside of my JD310 and spent an unhappy hour cleaning things up with the spray. But it was worth it to see clean new mechanical components appear where only blobs of ancient grease-hardened mud had existed a few minutes before.

After things were clean it was easy to find the leak. It turned out to be a leak in the connection to the hydraulic return hose. That's a molded hose on the JD310, and the JD dealer said they sell quite a few of them.
rScotty

 

[mmranch]

Thanks for all the ideas! As I've been snow plowing, I've been watching and it doesn't appear that the tractor has been leaking on the ground in recent days.

The spots where I did see streams before on the ground were in a section where she was definitely pushing a very heavy snow load in low gear, so that probably has something to do with it. Maybe it was blowing oil out the vent tube under load (but the area at the end of the tube looks too dry to have been sending a stream out). She has drip pans under her where she's parked but not a lot of oil is collected. This investigation will have to wait til spring probably as she's needed too much at the moment. I'll get the PTO leak fixed first and then re-evaluate.

Thanks again.