790 front axle leak

[beenthere]

I have a 2004 790 4wd with loader. 243hrs. I was bushogging yesterday and noticed gear oil leaking onto right front axle. Everything seems to be working fine otherwise. Could a seal be bad? I've read about gear problems but 4wd seams to be working fine. Any ideas? I'm almost afraid to ask.

Loosen the dip stick plug, as if it is tight, then the axle isn't vented. So when the oil gets warm, it squeezes past the seals. Works for my 4300. You may have just filled it to the brim too, and no room for expansion. There is a thread here somewhere that tells about a mod to vent the dip stick plug.
At least worth a try to see if the oil stops leaking after hard use.

 

[RoyJackson]

Loosen the dip stick plug, as if it is tight, then the axle isn't vented. So when the oil gets warm, it squeezes past the seals. Works for my 4300. You may have just filled it to the brim too, and no room for expansion. There is a thread here somewhere that tells about a mod to vent the dip stick plug.
At least worth a try to see if the oil stops leaking after hard use.

That venting was done by TBN member Arribil...it's at least 15 to 18 months since he posted that.
However, IIRC, the 790 axles are already vented...but I'm relying on my memory on that...

 

[scdawg]

Thanks for all the info. I'm not much of a mechanic but those diagrams do look familiar.
I know that when I remove the dipstick to check the oil level, it often sounds like air pressure is being released. I did just top off the oil before my last use.

 

[rsewill]

I bought a 4100 this spring. It leaked from the left front seal. After reading this forum extensively I decided the easiest, albeit not the best, solution was to drill a pin hole in the filler cap. I filled the pin hole with gun grease which pushed out within a few minutes (on a 40F day so the front differential certainly didn't get very warm.) Still easier to add a bit of gear lube than to replace another seal. I have a dab of grease mostly sitting over the pin hole.

 

[Willl]

However, IIRC, the 790 axles are already vented...but I'm relying on my memory

Nope. At least not from the factory.

 

[RoyJackson]

Nope. At least not from the factory.

As I wrote, I was dependng on my memory.
There is a hole in the upper side of the casting. It's even shown in the 790 manual (pics posted on TBN somewhere). A thread (has to be close to 2 years old (or more) speculated it was a vent since it seemed to have no other purpose.
This is what got Arribil motivated to vent the front axle of his 4200 (see one of my previous posts in this thread).
So, it might be a vent...might be just some result from the casting process. So, unless you know otherwise, you can't say it's not a vent...
My 790 has been gone for 18 months (along with the manuals).
Do you own a 790, Will? If you have one, take a look at the top of your front axle. IIRC, it's near the front differential.

 

[Tractor Pilot]

That venting was done by TBN member Arribil...it's at least 15 to 18 months since he posted that.
However, IIRC, the 790 axles are already vented...but I'm relying on my memory on that...

Here is the link to the thread Roy mentioned:
http://www.tractorbynet.com/forums/...ing/168295-does-everyone-have-front-axle.html

 

[Mighty Dodge]

My 4200 had a leak at the front axle. This was after I used the loader to lift the front of the tractor to fix a tire. There's a little end play in the spindle and I guess it disrupted the seal between the spindle and seal lip. Anyway after a week or so it stopped on it's own. Maybe you'll luck out and it'll stop. Has it been leaking long?

John

 

[scdawg]

It just started leaking this weekend. I noticed it on Friday after bushhogging a couple of hours. I'll run it for a while and keep my eye on the fluid level. Hopefully it will stop on its own.

 

[godaddy]

Mine developed a leak on the right side also. I noticed also that when I would check the front gear oil that it would have a little pressure in the front diff. after use(normal). Mine is a 2001 and has no vent. So, I drilled a small hole in the dip stick and placed some foam in it for a filter like. Mine does not leak anymore now. Not hard to replace one though. Did the left side acouple yrs ago.