More on leaking axle seals and vents

[arrabil]

I found corrosion there and on parts of the bearings. Disassembly was immediately after draining the oil.

Is that part of what leads you to believe hydraulic oil doesn't belong in the axle? Or did you just chalk it up to the difficult maintenance of a rental vehicle?

 

[jimgerken]

arrabill, and interested others: You are doing some pretty cool and advanced engineering here, keep up the good work.
Here's something that might help. Hopefully I read carefully enough and didn't miss this suggestion already, but here goes. I have seen a few gearboxes are vented to a closed bellows plastic part. I own an ATV which uses this method on three different gearboxes on the unit. I assume the bellows would be sized according to the gearbox volume. On my atv, the gearboxes hold around a quart, and the bellows is about an inch diameter and three inches long. For clarity, the bellows is closed on one end, and the other end clamps onto the vent tube that comes out of the top of the gearbox. My understanding of its function is that it would allow expansion and contraction, but not require an overflow bottle. Also, it gives the advantage of not allowing any opening to the atmosphere, to collect moisture. Obviously, the bellows venting method would allow operation under water also, with no contamination potential.
I wish I had a nice picture of it, but not here today. Could get a pic in a day or two if the concept is unclear.
Good luck. Keep us posted. Good stuff.

 

[arrabil]

You are doing some pretty cool and advanced engineering here, keep up the good work.

Thanks for the support! Not sure its all that advanced though.

Yeah, I would appreciate a picture of what you're describing. This is the second time someone has mentioned that contraption to me and while I understand what you're saying.... a picture is worth a thousand words as they say.

 

[jimgerken]

I could take a picture of mine, but this link may explain it even better...
Poly Performance JEEP/TRUCK & BUGGY :: Drivetrain/Differential :: Differential Housing & Accessories :: Trail-Gear :: Trail-Gear Creeper Breather - Differential Breather Kit - 4x4 Off-Road, JK Synergy Suspension Systems, Fox Racing Shox, Beard, CNC B

 

[arrabil]

Ah. That may work* on an straight axle that doesn't really have all that much fluid in it but it would just have the very same problems I experienced earlier on the much fuller portal-type axle on the tractor.

* Whether or not it even does anything useful is quite debatable if you ask me.

 

[dfkrug]

Is that part of what leads you to believe hydraulic oil doesn't belong in the axle? Or did you just chalk it up to the difficult maintenance of a rental vehicle?

A year ago, I was deep into my MFWD axle rebuild. It is buried in my
4300 thread, starting at post #115 on page 3:
http://www.tractorbynet.com/forums/parts-repairs/146974-john-deere-4300-complete-rebuild-3.html

The short answer is yes, that is one of the reasons I am concerned about
using THF in final drives. In rental service, lots of bad things do happen,
but the equipment does get frequent use and maintenance. In my
experience, the rental yard was good at keeping fluids up, oils changed,
and zerks greased.

 

[arrabil]

So I figured out the hex cap size is 14mm. Its actually on the jdparts site, 0.551" drive size, just a little cryptic with the inches measurement on a metric fastener. Hopefully I can pick up a socket tomorrow morning. I figure I need a right angle 1/4" NPT hose barb too since I have to go around the fan shroud. I'm gonna start a new thread when I start tearing into it.

 

[arrabil]

Foiled by the 14mm hex socket. Been to True Value, Tractor Supply, Home Depot, and Advance Auto. Not even a 14mm allen key let alone the socket. Its a special order at Sears too. So I had to go to eBay for it. I did buy the right angle barb and and everything else I need though....

 

[dfkrug]

So I figured out the hex cap size is 14mm. Its actually on the jdparts site, 0.551" drive size, just a little cryptic with the inches measurement on a metric fastener.

I'm a little late, but I did check and it is a 14mm socket head bolt as you
found out. I have a set of 1/2" drive hex (allen) sockets that have a 14
and 17mm size. Very reasonablly priced, from HF. I have a SnapOn 12mm
1/2" drive hex socket that cost more than the whole HF set.

Anyway, I just removed one of my tie rod ends, and I don't think you
need to remove the cyl supports at all (see photo).

 

[arrabil]

Anyway, I just removed one of my tie rod ends, and I don't think you need to remove the cyl supports at all (see photo).

I can't remove the pumpkin without pulling the whole steering assembly out of the way.

I was just at HF getting a small punch for the driveshaft roll pin. Didn't think to look for an allen key there. Doesn't matter I guess, the tracking says the socket I ordered is within 50 miles of my place. Probably get it tomorrow though we'll see when I can start on this again (gotta fix a fuel pump for the neighbor and gotta a line on a backhoe I may need to pickup this week).