Rear Axle leak JM284

[linus69]

I finally got tired of the puddle of hyd fluid on the garage floor and tore into the leak that was causing it.
I drained the hyd fluid from the rear, jacked up and blocked the left rear, removed the large and HEAVY rear wheel.
Next came the keyed wheel hub, that took plenty of WD40 and controlled thunping with a lump hammer to get off without doing damage,
Then came the 4 bolt square bearing cover, that also resisted coming off and required much cursing. Contained in that cover were the two twin (50 72 12) oil seals, and mine were shot, there was a piece of the outer seal that was broken off.
Here is a shot of where the mystery rear zerk fittings deposit their grease, there is plenty of room here for grease and I`m heavy handed and their isn`t much grease here.



Here is the end cap after the old seals were removed by a large screw driver and some light hammer blows from the backside.



Here is a shot of the new oil seals installed, they both go in facing the same direction, one up against the other. I used a short piece of 2in pvc pipe and a lump hammer to seat the seals, I put a very light coat of grease on the walls of the bearing end cap to help things along.



I didn`t have a new gasket for the bearing cap so I buttered up the old one with red Permatex gasket maker and put it all back together with fresh fluid. I did all the other hyd fluids, engine oil,and injector pump oil too.I use 15/40 weight diesel oil.
The leak is now gone and I`ll be ordering more of those seals soon, they were $5.80 each from Chris at
www.jmparts.com/

[carld]

Are you running hyd fluid in your transmission?

[grohgreg]

Carl's question is valid. You should be using gear oil in the transmission and both differentials. If you're using hydraulic fluid or UTF, that stuff is thin enough to where one or more leaks would not be uncommon. 80W90 is typical for cold to moderate climates. It's hot enough here in July/Aug that I use 85W140 year round now.

//greg//

[GuglioLS]

Paul -"two twin (50 72 12) oil seals, and mine were shot, there was a piece of the outer seal that was broken off."

Paul, nice job taking everything apart and fixing it. My Ford tractor specifies UTF because the hydraulic reservoir is the rear end lubricant as well. Those seals were probable damaged when installed or just went bad due to the crappy rubber they are made of. Did you use OEM seals or did you get replacements from a local bearing and seal shop? Whenever I have a bad oil seal I first try to get them from a local shop that are made out of higher quality materials. Most bearing a seal suppliers can match up just about anything.

My experience is that Shot / Leaking seals will leak no matter what fluid they are trying to hold back. Sure the leak will be slower with thicker fluid, but it will still leak if the seal is damaged. I know you did this a while back, how is it holding up?

Larry

[grohgreg]

gugliols said:

Those seals were probable damaged when installed or just went bad due to the crappy rubber they are made of.

That kind of damage can be self-inflicted too. The FB50x72x12 outer seal can be compromised by forcing too much grease into the zerk that provides lubrication to the outer bearing.

//greg//

[GuglioLS]

That kind of damage can be self-inflicted too. The FB50x72x12 outer seal can be compromised by forcing too much grease into the zerk that provides lubrication to the outer bearing.

Greg,

Glad you brought that up, it's an Excellent point. There are a few grease zerk's on the axle housings on some of these tractors that have no business being there. By pumping in grease all it does is blow out a seal, other zerks allow you to pump grease into bearings that are already lubricated with gear oil. I guess the moral of the story is to only pump is a couple of shots of grease and not to frequently?

Larry

[linus69]

Hi Gents,
The photo site I`ve been using "All You Can Upload" is closed and no longer accepting photos. I was curious if my old photos were still coming up in my posts and this is the 1st one I checked.
I see a couple of questions were asked that I never saw, so I never answered, sorry.
Carld asked if use hyd fluid in tranny......Yes I use hyd fluid in everything except the engine.
LarryG asked how is it holding up......It has been holding up just fine, no puddle on the floor.

Paul

[Ronmar]

Hydraulic fluid IMO is not heavy, thick and sticky enough to properly lubricate the bearings and straight cut gears in a 284's gearboxes. That is why they make stuff called GEAR oil...

That hydraulic oil, particularly when warm, when it is sandwitched between gear teeth that are put under pressure(teeth transmitting torque from one shaft to another), will more easilly give with the pressure and be squeezed out of the space, allowing metal to metal contact on the gear teeth.

[GuglioLS]

My old 1953 ford tractor calls for UTF (universal tractor fluid) in the transmission and rear-end. It's Viscosity range is equivalent to a 5W20 engine oil, however it contains extreme pressure (EP) additives and anti-wear additives to cope with the sliding action of hypoid bevel gears, yet is thin enough for Hydraulic systems. Ford and many other tractor brands use the transmission and rear-end as the hydraulic sump and therefore require the thinner UTF lubricant. I've used UTF in that tractor going on 26 years without any ill effects to the transmission gears, bearings or seals. Check this UTF Application PDF

After using this thin fluid for so many years, makes me wonder about the real need for for such thick and ungodly smelling gear lubricants in a tractor? Maybe it's real purpose is for automobiles and trucks running at highway speeds as opposed to our super slow moving tractors? Just a thought worth pondering. Not that there is anything wrong with using heavy weight gear oil. I use 80W90 in my Jinma transmission and rear end. One of the advantages to the thicker gear oil is to distribute the oil more evenly throughout the gear train. However I believe the UTF which is essentially the viscosity of AW46 hydraulic fluid except with EP additives seems to lubricate just as well, especially for a slow moving tractor.

As a side note, I use UTF in the Hydraulic system of my Jinma and Komatsu Dozer. The Dozer manual calls for 10W40 motor oil for the hydraulics, transmission, and wet clutch. I called the Komatsu service department about using motor oil in the hydraulics and he said yep, that's whats in the manual and that is what they use to service all the heavy Komatsu equipment. I choose to use UTF hydraulic / transmission fluid so far so good.

Paul,

Out of curiosity - do you use Hydraulic fluid or a UTF?, the viscosity of both is virtually the same, except UTF has EP additives. What made you decide to use hydraulic fluid as opposed to gear oil?

Larry

[linus69]

Hey Larry,
I have used Universal Tractor Fluid since day one in my 284 and I have been more than pleased with how it has performed in my tractor for the past 1/2 decade. I had the opportunity to compare front 4x4 bevel drive gears old and new side by side on the bench last summer and found no discernible wear at all.
I change out my UTF about every 50hrs and always examine it closely and never find any evidence of the gears wearing or breaking down in any way. The diesel mechanics at my job told me UTF would be fine and I called the fellow who imports the JM284 under the Emery Built name and he advised me the same.
Put that together with the manufacturers recommendation and I was convinced, I use UTF in everything except the engine and injector pump. This of course is strictly a point of personnel preference, I by no means was trying to reignite the tractor lubrication argument that has grinded on ad nauseam on various forums for years.
I just wanted to answer a couple of questions that had been posted to me. I certainly wasn`t looking for any lectures from any grohgreg wannabes.

Paul