Another 4400 front axle leaking!

[arrabil]

That nut looks exactly like the one on my Ford trucks. Has anyone taken a standard 4wd spanner socket to it and seen if it fits?

 

[dfkrug]

I think it is a mistake to use hydraulic fluid instead of 90wt gear oil in
there. I think you would have less leaks with gear oil, and probably not
the corrosion I found in mine.

 

[defed]

i used the low vis hy-gard as recommended. i was thinking the same thing about the thin oil leaking....the old oil had water in it and was a nasty syrupy mess....it barely leaked out of the drain plugs, let alone a seal.

but, it still took a week for it to leak, and then that was sudden, when the tractor hadn't been used in 5 days.

 

[RickB]

I think it is a mistake to use hydraulic fluid instead of 90wt gear oil in
there. I think you would have less leaks with gear oil, and probably not
the corrosion I found in mine.

New Holland, Deere, and for the most part Kubota disagree.

 

[arrabil]

The thinner oil will get into crevices, bearing spaces, and between gear teeth far easier than 90w gear oil which is likely why its specified. There are all kinds of manual automotive transmissions that use ATF (also a hydraulic fluid) instead of MTF for the very same reason.

 

[Tunguska]

Interesting discussion. The MFWD on my 870 requires JD GL-5 gear lube. I wonder what changed over the years now that Lo-Vis Hygard is called for.

 

[arrabil]

I wonder what changed over the years now that Lo-Vis Hygard is called for.

Likely the same thing that happened with automotive trannys... the manufacturers realized they would get the same protection from thinner oils with less warranty repairs.

 

[dfkrug]

Likely the same thing that happened with automotive trannys... the manufacturers realized they would get the same protection from thinner oils with less warranty repairs.

There is another thing happening in the automotive realm: lower viscosity
oils in manual gearboxes help with gas mileage. Not an issue for tractors.

Many tractor owners manuals say either hyd oil or gear oil is OK. Others
come with hyd oil in the MFWD axle, but specify gear oil (my Kiotis). My
Kubotas specified gear oil, and my oldest one was pristime inside.

I know the 4x00s are specced for JD hyd oil, but this axle (Spicer) would
be better served with gear oil, IMO. There have been a lot of design
goofs on this tractor, and several re-designs of the MFWD axle in just a
few years. JD is certainly not infallible....I think they made a mistake (or
Spicer did), speccing hyd oil. I went to GL-5.

 

[arrabil]

I think they made a mistake (or Spicer did), speccing hyd oil. I went to GL-5.

Realistically, at 5mph, I doubt it matters one way or another. Did you use the same amount of gear oil as specified for hydraulic fluid? I'm wondering if you know if they expand at different rates?

 

[dfkrug]

Realistically, at 5mph, I doubt it matters one way or another. Did you use the same amount of gear oil as specified for hydraulic fluid? I'm wondering if you know if they expand at different rates?

I just fill until the dip stick or sight glass says I am full. It takes a while
to get the oil distributed. I don't measure the amount I put in, but it is
in the neighborhood of 5 qts.

Even at 5mph, your tractor's bevel gears are under a lot of pressure, pushing
and pulling heavy things. Max protection is called for, IMO, at least if you
want the tractor to last well past the warranty period.

BTW, gear oil is still specced for many many final drives in cars, where
the greatest gear forces are.