1705 Front axle fill cap pressure release

[Jolson1705]

Does anyone know how the front axle fill cap is supposed to release the pressure that builds up during use.
I see the there is a v shape cut in the threads, but I don't see any way for the pressure to release.
When I removed the fill cap after using the tractor, there was obvious pressure built up.
I just don't want to blow my axle seals. Thanks for any info.

 

[Dmacleo]

see that thing in center of cap that looks like casting mark?
keep it clean. NEVER use tools/drills on it.
its the actual vent, a little pressure is fine, we all see it. axle won't puke fluid all over unless that center is plugged and crap gets really really REALLY hot. then at that point it has expanded enough (remember fluid not full to top of housing) and will come thru hole.
fwiw my GC2400 uses same part on left front axle as your GC1705....and my hydro fill tube uses same exaxt part on it so...chance your hydro fill tube uses same part.

 

[Dmacleo]

no need to go thru all that. OP did not say was any leaks. was worried about the pressure differential.
little pressure is ok. its normal actually, especially if its warmed up when you pull it to check.
overfill (if that plug is clean) may work thru it. its meant to do that.
I'm at 610 hrs on my GC2400 with no leaks. 385 hours since I bought it 10-2020.
been thru 2 full services. ug about to buy fluids for another full service...yay.
keep the 2 plugs (axle and hydro fill) clean and you are ok.

in past few years (2015 to present) maintained 5 GC series. my 2010 GC2400 (bought 10-2020), boss 2015 GC1710 then 2020 GC1723, neighbor 2021 GC1723, other neighbor 2021 GC1725M.
now (since Dec 2021) down to maintaining my 2010 GC2400, neighbor 2021 GC1723 and other neighbor 2021 GC1725M.
oh yeah, 2012 MF1532.

never have had to use unapproved fluid on any of them. hell for the 4 GC series NOT my own would have ruined warranty.

edit:had to correct the years on 1 GC1723 units. one bought in 2020.

 

[Jolson1705]

see that thing in center of cap that looks like casting mark?
keep it clean. NEVER use tools/drills on it.
its the actual vent, a little pressure is fine, we all see it. axle won't puke fluid all over unless that center is plugged and crap gets really really REALLY hot. then at that point it has expanded enough (remember fluid not full to top of housing) and will come thru hole.
fwiw my GC2400 uses same part on left front axle as your GC1705....and my hydro fill tube uses same exaxt part on it so...chance your hydro fill tube uses same part.

View attachment 823828

Thanks for the information. That hole seems so miniscule, that it was hard to believe that it could actually vent.
You have put my mind at ease. Thanks again. This is such a great to get helpful information!

 

[Dmacleo]

Thanks for the information. That hole seems so miniscule, that it was hard to believe that it could actually vent.
You have put my mind at ease. Thanks again. This is such a great to get helpful information!

if you look close on inside of plug on the "shorter" side (iirc) you will see an approx 1/8 inch slot that runs up into top of plug, thats the channel to that vent.

 

[jeepcj7]

The front axle oil level should be 1/2 way up the horizontal shaft that is visible thru the fill hole. After draining the oil, refill it., wait 5 minutes and recheck the level. If you dump the oil in to fast it can create a few air pockets that will affect the visible oil level. If you have a small leak in the seals you can use gear oil in the front axle - it won't hurt anything because the front axle is its own reservoir.

 

[GeneV]

Don't overfill that axle, that's the main thing.