Another 4400 front axle leaking!

[arrabil]

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

I'm pretty sure the clearances on manual trannies that specify ATF are smaller than those in an axle. I don't know of any final drives spec'd for anything but gear oil do you?

Speaking of which.... all automotive axles are vented. I don't think the 4000 series axle is vented. So maybe thats why minimally expanding hydraulic fluid is specified?

 

[captin_insano]

I'm really surprised the axle has no vent on it. The air is what expands when its heated during use and it finds its way out. If you get it in water, or maybe even wash it after use the air cools creating a vacume and it will suck water back in. The milky thick oil someone mentioned earlier was caused by this. I think if I had to do this repair I'd look for a way to put a vent on the axle.

 

[defed]

i was considering looking for a vented type cap for the fill plug. mine leaks erratically now. it leaked 1/2 quart suddenly after sitting idle for 5 days, then none sitting one day (after refilling). i used it alot yesterday, and it was dripping a bit here and there. and when parked, was dripping into the pan i put there to monitor how much leaks.

btw, where do you find the spec number of the axle as listed in jdparts? i read somewhere that it was near the fill plug, but i don't see anything except 'spicer'.

 

[arrabil]

Gear oil very much does expand. Around 10% at higher working temps. The air pressurizes significantly while the gear oil does not. Neither should find their way out of the axle while running. You should hear pressure release when removing the axle plug on this front axle. Anywhere air can leak out will be a place the axle oil can leak out. You should definitely not be contaminating the axle with water after washing it. Thats just a sign of already failed parts.

defed, sounds like time for a full axle seal rebuild. 1/2 quart is a lot of leakage.

 

[dfkrug]

I'm pretty sure the clearances on manual trannies that specify ATF are smaller than those in an axle. I don't know of any final drives spec'd for anything but gear oil do you?

Speaking of which.... all automotive axles are vented. I don't think the 4000 series axle is vented. So maybe thats why minimally expanding hydraulic fluid is specified?

Clearances inside manual trannies may be tighter, but the greatest forces
are always in the final drive due to torque multiplication. I know that Honda/
Acura FWDs use 30wt motor oil in their manual trannies, and the tranny
is integrated with the final drive. I suspect that many (most?) FWD cars
have integrated trannies/final drives. I was surprised when I found out
Honda used motor oil (in our long-gone Acura Integra).

As for venting, all the 4x4 tractors I have had were unvented in the front,
regardless of whether gear oil or hyd was specced. Perhaps tractor MFWD
axles are not vented because they are highly exposed to mud or water
above the fill port. If someone wants to try to vent their axle, I suggest
using a protected rubber tube that ends in a higher location. Off roaders
do that for their rear end vents to keep water out of there.

 

[dfkrug]

btw, where do you find the spec number of the axle as listed in jdparts? i read somewhere that it was near the fill plug, but i don't see anything except 'spicer'.

Right here (photo).

On my axle, I could see the date, but not the part #. I had to remove
the paint. This old unit has no manufacturer stamp, but it seems to share
molds with Spicer-marked units on later 4x00s, 4x10s, and 3x20s.

 

[arrabil]

So we've seen gear oil, hydraulic fluid, engine oil, and ATF spec'd for axles.... I really think that means they're all of high enough quality nowadays to use any of them.

If someone wants to try to vent their axle, I suggest
using a protected rubber tube that ends in a higher location. Off roaders
do that for their rear end vents to keep water out of there.

I vent both axles, the transfer case, and the transmission to the hightest point in the engine on my off-roader.

 

[defed]

defed, sounds like time for a full axle seal rebuild. 1/2 quart is a lot of leakage.

i have to call the dealer 1st and see what they will do under a drivetrain warranty. if nothing, i will do at least the one side. probably leave the 2nd side until it starts to leak.

 

[dfkrug]

Yes, oil expands when it gets hot. So much so that the SCCA rule book
requires that gearbox and final drive vents use hoses and remote-mounted
catch reservoirs to avoid getting any oil on the race track.

Certainly, oil in a MFWD axle can get hot under exteme conditions, too.
Apparently, the manufacturers have decided that the axles can withstand
the internal pressures without bad consequences and axle vents would
cause more problems than they solved.

 

[defed]

talked to the dealership today....they will only cover 1/2 the cost, or give me the parts to do it. i was kind of irritated that my 'drive train' warranty wasn't going to cover the full cost. he said...it's a used tractor...i said...but you gave me a 30 hr warranty on the engine and drive train.

so i talked to the service manager about some details of the job...like, do you have to disturb the hub seal to get the shaft (kingpin?) and all that out the bottom plug. he said it can all be removed w/o taking the hub apart, or without removing the shoulder from the axle. it is easier to do the work on the bench, but he said it's a pain to get the shoulder back onto the axle, so he just does it on the tractor. so it sounds like i don't HAVE to do the hub seal to do the shoulder/knuckle seal. if they will give me the parts to do both, i will. if not, i might just wait until the hub seal leaks. the hub seal seems alot easier to do at any time....except for the fact of draining and cleaning everything twice...maybe i'll just do both! he said i could borrow their spanner wrench for the nut.

btw, i was quoted $400 to replace it. i'd have to pay $200. think i will do it myself.