Transfer Case Fluid
JK Enthusiast
Joined: Dec 2011
Posts: 195
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From: Bakersfield
Originally Posted by JKingAround
Use it for the manual Trans only transfer case takes automatic Trans fluid
Thread Starter
JK Enthusiast
Joined: Nov 2009
Posts: 118
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From: Johnson City, Tennessee
You quoted an AMSOIL vendor...his job is to sell his brand of oil. And many of the AMSOIL products do NOT meet API specifications.
I agree with the need for extreme pressure additives in ring and pinion gears. but how does a bevel or spiral gear have LESS load? we are transmitting the same amount of torque in the transfer case as we are in the differential...
Personally, I think they spec'ed AFT4+ since it gives better gear efficiency that the heavier gear oil AND is already in stock at all the dealerships.
My question still remains, why NOT tractor hydraulic oil, in many pieces of heavy equipment, the gear boxes are serviced by the hyrdaulic system, which means they will never run low or hot, since those systems have a surge tank and a cooler.
Of course, this is an moot point since I put in ATF in the transfer case yesterday, with a VERY slow gallon bucket pump.
Howard
I agree with the need for extreme pressure additives in ring and pinion gears. but how does a bevel or spiral gear have LESS load? we are transmitting the same amount of torque in the transfer case as we are in the differential...
Personally, I think they spec'ed AFT4+ since it gives better gear efficiency that the heavier gear oil AND is already in stock at all the dealerships.
My question still remains, why NOT tractor hydraulic oil, in many pieces of heavy equipment, the gear boxes are serviced by the hyrdaulic system, which means they will never run low or hot, since those systems have a surge tank and a cooler.
Of course, this is an moot point since I put in ATF in the transfer case yesterday, with a VERY slow gallon bucket pump.
Howard
I honestly don't know myself, but I found this answer on another web site. Seems to make sense:
The use of ATF is very common in both manual trans and transfer case applications. The criteria for these applications is to have a lubricant with good anti-wear additives and also provide excellent flow to the bearings in the unit. Many people make a mistake by putting thicker gear lubes in these units. Gear lubes are made to handle the heavy loads and the contact and slide operation of the ring and pinion gears in a differential. The Extreme Pressure (EP) additives in GL's are sulphur based and will chemically attach to the surface of the metal under load. When the oil film gets blown away the EP will prevent steel to steel contact and that is where the wear would occur. Since there is no contact slide in the transfer case or the transmission (simple bevel gear sets)then only anti-wear lubes are required. Anti-wear additives such as zinc are only loosely attached to the surface and can be easily scraped off in contact and slide appliations.
So the use of ATF is correct for the transfer case and the use of motor oil would be a qualified second choice. Don't forget the use of automatic transmissions is prevalent in heavy duty applications and the ATF has to lube all the gears and bearings in those HD auto trans. Synthetic ATF is superior to petroleum because of the synthetic basestock not the anti-wear additives. The temperature range of synthetic is more than twice the petroleum and the natural film strength is more than twice the petroleum.
One last thing to note: most gear sets (transmissions, transfer cases etc) have bearing failure much more than gear failure. Why is this? Because people use a thick gear lube where they should have use a light weight oil such as ATF and the bearings get starved for oil. The thick stuff can't get into the bearings tight clearances.
In any case stick with the manufacturers recommendation in the owners manual. They know what it is designed to take and that is the best bet.
ALT Dan Watson
AMSOIL Synthetics, AMSOIL Dealers, Synthetic Engine Oil, Synthetic vs Oil Comparisons - AMSOIL
(Copied from: Transfer case lube?)
It sounds like basically the t-case doesn't need high viscosity oil since it is using straight bevel gears and a chain drive, and the use of (thinner) ATF helps extend the life of the bearings. Spiral bevel gears need specialized gear oil (thicker) because of the shearing action that occurs as the spiral teeth mesh against each other. But there are no spiral bevel gears in a typical transfer case. This guy's answer makes sense to me.
The use of ATF is very common in both manual trans and transfer case applications. The criteria for these applications is to have a lubricant with good anti-wear additives and also provide excellent flow to the bearings in the unit. Many people make a mistake by putting thicker gear lubes in these units. Gear lubes are made to handle the heavy loads and the contact and slide operation of the ring and pinion gears in a differential. The Extreme Pressure (EP) additives in GL's are sulphur based and will chemically attach to the surface of the metal under load. When the oil film gets blown away the EP will prevent steel to steel contact and that is where the wear would occur. Since there is no contact slide in the transfer case or the transmission (simple bevel gear sets)then only anti-wear lubes are required. Anti-wear additives such as zinc are only loosely attached to the surface and can be easily scraped off in contact and slide appliations.
So the use of ATF is correct for the transfer case and the use of motor oil would be a qualified second choice. Don't forget the use of automatic transmissions is prevalent in heavy duty applications and the ATF has to lube all the gears and bearings in those HD auto trans. Synthetic ATF is superior to petroleum because of the synthetic basestock not the anti-wear additives. The temperature range of synthetic is more than twice the petroleum and the natural film strength is more than twice the petroleum.
One last thing to note: most gear sets (transmissions, transfer cases etc) have bearing failure much more than gear failure. Why is this? Because people use a thick gear lube where they should have use a light weight oil such as ATF and the bearings get starved for oil. The thick stuff can't get into the bearings tight clearances.
In any case stick with the manufacturers recommendation in the owners manual. They know what it is designed to take and that is the best bet.
ALT Dan Watson
AMSOIL Synthetics, AMSOIL Dealers, Synthetic Engine Oil, Synthetic vs Oil Comparisons - AMSOIL
(Copied from: Transfer case lube?)
It sounds like basically the t-case doesn't need high viscosity oil since it is using straight bevel gears and a chain drive, and the use of (thinner) ATF helps extend the life of the bearings. Spiral bevel gears need specialized gear oil (thicker) because of the shearing action that occurs as the spiral teeth mesh against each other. But there are no spiral bevel gears in a typical transfer case. This guy's answer makes sense to me.
JK Enthusiast
Joined: Oct 2011
Posts: 285
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From: Central PA
FWIW, the transfer case (NV247) in my Grand Cherokee uses the super-secret Mopar transfer case lubricant part number 05016796. I still buy it at the dealership because I never did find a suitable (read: less expensive) substitute, but then again, I wasn't searching that hard either because I don't change it THAT frequently.
I've been told that this stuff is "Tractor Oil", although I have no idea what viscosity it is or what additives are in it, if any. It seemed a bit more viscous than ATF+4, but not THAT much more.
I've been told that this stuff is "Tractor Oil", although I have no idea what viscosity it is or what additives are in it, if any. It seemed a bit more viscous than ATF+4, but not THAT much more.
Thread Starter
JK Enthusiast
Joined: Nov 2009
Posts: 118
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From: Johnson City, Tennessee
Time to start matching spec's up...we can take the mopar tranny lube spec and see how it compares with ATF and hydraulic oil. We don't need the friction modifiers that ATF has (and ATF is only cheap because they sell A LOT of it ).
I dislike stocking too many different speciality lubricants, but a gallon of this and a quart of this have saved many a trip to town...where I live, the nearest autoparts store is a good hour round trip.
Did a service on a 30 year old motorcycle this evening with 20w-50 motorcycle spec oil and GL-5 gear lube...a little more than a gallon in total.
Howard
I dislike stocking too many different speciality lubricants, but a gallon of this and a quart of this have saved many a trip to town...where I live, the nearest autoparts store is a good hour round trip.
Did a service on a 30 year old motorcycle this evening with 20w-50 motorcycle spec oil and GL-5 gear lube...a little more than a gallon in total.
Howard
JK Enthusiast
Joined: Jan 2011
Posts: 210
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From: Coleman, Tx
Just fill your tranny with tractor hydronic oil if u think it's close to ATF4 specs, it should be just fine. I know it's crazy hard to buy 2 quarts of ATF every 30k. Also if u are a engineer than u should be able to understand the different loads put on way different bearing surfaces. A differential is not just up against a linear load but also a high sheer load and t cases are only linear (round bearings). Last time I checked John Deer made jeep parts so I would quit asking questions becouse you clearly are sure of the capabilities of fluids
Thread Starter
JK Enthusiast
Joined: Nov 2009
Posts: 118
Likes: 0
From: Johnson City, Tennessee
Just fill your tranny with tractor hydronic oil if u think it's close to ATF4 specs, it should be just fine. I know it's crazy hard to buy 2 quarts of ATF every 30k. Also if u are a engineer than u should be able to understand the different loads put on way different bearing surfaces. A differential is not just up against a linear load but also a high sheer load and t cases are only linear (round bearings). Last time I checked John Deer made jeep parts so I would quit asking questions becouse you clearly are sure of the capabilities of fluids
And since I also restore and operate vintage vehicles, where the original lubricant is no longer available, I have to figure out what on the shelf will give decent service.
And I thought you boys from Texas were taught to respect your elders...
Howard