M210/D44 specs for truetrac

[chevymitchell]

Be careful about putting a limited slip in the front. If you don't have a full time 4wd system the clutches in the limited slip will wear out quickly. With the part time 4wd the FAD disconnects one side of the axle allowing one wheel to free wheel while in 2wd. The other axle is still connected to the diff. With an open diff this is fine, the spider gears in the diff can just spin while not turning the drive shaft. This is done to help with mileage by not having to spin the ring gear, driveshaft and transfer case internals while not in use. Also saves on some wear. With a limited slip the clutches try to prevent this by applying friction. So either the diff, driveshaft and transfer case internals spin or the clutches slip and the spider gears spin. My guess is at first it will be a combination of both until the clutches wear out, which I think will be rather quickly. With the one axle disconnected there is no dynamic load and the static loads on the clutches will be pretty lite. I don't think the clutches will stand a chance.

With a truetrac axle rotations are controlled by worm gears in the diff, so it won't wear out the same. It will probably effect the part time system the same and you can expect a hit on mileage.

If we still have part-time hubs, like the old days where both wheels are disconnected, none of this would be an issue, but we don't. FAD only disconnects one axle.

While I know you didn't want it, a locker may be your best bet. Lock it when needed, and leave it open for handling and better steering when in 4wd.

Just my $.02

This is really solid advice.^

I talked with Paul this morning and he also shares this same thought.

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[Kurt0]

Be careful about putting a limited slip in the front. If you don't have a full time 4wd system the clutches in the limited slip will wear out quickly. With the part time 4wd the FAD disconnects one side of the axle allowing one wheel to free wheel while in 2wd. The other axle is still connected to the diff. With an open diff this is fine, the spider gears in the diff can just spin while not turning the drive shaft. This is done to help with mileage by not having to spin the ring gear, driveshaft and transfer case internals while not in use. Also saves on some wear. With a limited slip the clutches try to prevent this by applying friction. So either the diff, driveshaft and transfer case internals spin or the clutches slip and the spider gears spin. My guess is at first it will be a combination of both until the clutches wear out, which I think will be rather quickly. With the one axle disconnected there is no dynamic load and the static loads on the clutches will be pretty lite. I don't think the clutches will stand a chance.

With a truetrac axle rotations are controlled by worm gears in the diff, so it won't wear out the same. It will probably effect the part time system the same and you can expect a hit on mileage.

If we still have part-time hubs, like the old days where both wheels are disconnected, none of this would be an issue, but we don't. FAD only disconnects one axle.

While I know you didn't want it, a locker may be your best bet. Lock it when needed, and leave it open for handling and better steering when in 4wd.

Just my $.02

so youre saying the axial forces from the driveshaft applying torque arent required to wear out the clutch packs? That would be a problem for sure. My understanding was that spinning wasnt enough to tension the clutch packs, that it had to be spin differential AND torque input. if spinning is enough to engage the packs then it is an issue.

ive decided just to wait for a helical/truetrac. Ill delay gear install a little since ill just be on pavement for a while; and worst case just open the diff back up later. I do not want a front locker.

 

[oldcjguy]

so youre saying the axial forces from the driveshaft applying torque arent required to wear out the clutch packs? That would be a problem for sure. My understanding was that spinning wasnt enough to tension the clutch packs, that it had to be spin differential AND torque input. if spinning is enough to engage the packs then it is an issue.

ive decided just to wait for a helical/truetrac. Ill delay gear install a little since ill just be on pavement for a while; and worst case just open the diff back up later. I do not want a front locker.

If the driveshaft isn't spinning and a wheel is then the spider gears are differentiating. That means the clutches and steels are rubbing against each other and will wear. I'm not going to pretend to be an expert on that unit, but normally there is a preload (static) force on the clutches, so I believe they will engage no matter what. At constant and high speeds (which is how the spider gears will be rotating inside the carrier when the vehicle is moving) it takes very little pressure to start wearing the clutches. The clutches sit on the sides, splined to the axles between the spider gears and the carrier. A static preload, springs, or just packing them in tight puts a load on the clutches. The rotation of the spider gears and the angles they are cut on applies a dynamic force against them. The spider gears force against the teeth of the other naturally pushes them out and into the clutches and carrier sides. So there's always "some" force.

Think about it. During normal driving in a straight line the spider gears need to do no differentiating because both wheels travel at the same speed. When making a turn the outer wheel speeds up slightly so the spider gears differentiate a little (less than a full rotation?). When one wheel is disconnected and the carrier is not rotating then the spider gears on each inner axle are differentiating. They're rotating in opposite directions of each other at the speed of the wheel. There are some pretty good youtube videos on how diffs work for those who haven't torn one apart or have a hard time picturing it.

I think you're smart to wait for the one you want. That's a good diff. Really cool how they work too.

 

[intentsrig]

Don't put a limited slip in the front. Selectable or nothing at all in my opinion.

 

[Kurt0]

Don't put a limited slip in the front. Selectable or nothing at all in my opinion.

a selectable locker up front would be the worst possible choice for my application and needs.

 

[intentsrig]

a selectable locker up front would be the worst possible choice for my application and needs.

So you want a limited slip style locker to lock in certain conditions while you are trying to turn?

Let me tell you how annoying that is on the trail...incredibly annoying. Even my friends with trailer rigs don't put limited slip style lockers in the front anymore since they can afford selectable lockers, turning can become a pita in the rocks, snow or anything where you are losing traction.

 

[Kurt0]

So you want a limited slip style locker to lock in certain conditions while you are trying to turn?

Let me tell you how annoying that is on the trail...incredibly annoying. Even my friends with trailer rigs don't put limited slip style lockers in the front anymore since they can afford selectable lockers, turning can become a pita in the rocks, snow or anything where you are losing traction.

thanks for the input. The questions i had about the fitting of diffs to the case and the technical questions about the engagement of the clutch packs have been answered.

dont mean to be a dick but ive been doing this a while. I have nearly 200hrs of professional driver instruction, not an insignificant amount of which was from Baja 500 winners. I have a formula 4 open wheel race car driver license. ive operated off road trucks across 4 continents. I know what i want the vehicle to do and when and from what driver input. What trailered rock bashers with drivers who never did a single school want is completely irrelevant and different than my intended uses.

 

[Tank the Jeep]

KurtO, I find it quite humorous how many armchair mechanics and my way or no way opinions you got from a simple question. I ran the truetrac front and rear in a jk and it worked great.

Remembering the installation, it think the truetrac wasn’t exactly right for the D30. I ordered it and the G2 gears from 4WD and they offered some guidance. The bolts were slightly big for the holes in the truetrac. I had to use a larger drill bit to make it work. Dont remember the specifics but it was very little. Probably a couple of thousandths. I wonder if this could be why it doesn’t fit the new axles. Anyway, hope you get your axle sorted out the way you want it.

 

[Kurt0]

KurtO, I find it quite humorous how many armchair mechanics and my way or no way opinions you got from a simple question. I ran the truetrac front and rear in a jk and it worked great.

Remembering the installation, it think the truetrac wasn’t exactly right for the D30. I ordered it and the G2 gears from 4WD and they offered some guidance. The bolts were slightly big for the holes in the truetrac. I had to use a larger drill bit to make it work. Dont remember the specifics but it was very little. Probably a couple of thousandths. I wonder if this could be why it doesn’t fit the new axles. Anyway, hope you get your axle sorted out the way you want it.

thanks for the tip. Ill take a look and keep investigating. @chevymitchell is staying gangster and helping me through the truetrac even if i have to wait a bit. Itll get sorted.

and yeah, youre right on the other stuff. sometimes people are just trying to be helpful, other times it is an inflated ego. doesnt bother me.

 

[oldcjguy]

So you want a limited slip style locker to lock in certain conditions while you are trying to turn?

Let me tell you how annoying that is on the trail...incredibly annoying. Even my friends with trailer rigs don't put limited slip style lockers in the front anymore since they can afford selectable lockers, turning can become a pita in the rocks, snow or anything where you are losing traction.

Limited slip diffs are not lockers. Some brands make that confusing with names like "trak-loc" (which is not a locking diff, but a clutch type limited slip diff). Limited slip diffs are not part time lockers, they do not lock, they attempt to limit the amount of slip between the 2 axles at the diff. JLs with open diffs do this by the traction control system and applying the brakes at individual wheels. While they are not as effective as a locker for rock climbing they have advantages over lockers in other situations since they are not an on or off feature. It depends on what you're doing with your rig.

 

[intentsrig]

Limited slip diffs are not lockers. Some brands make that confusing with names like "trak-loc" (which is not a locking diff, but a clutch type limited slip diff). Limited slip diffs are not part time lockers, they do not lock, they attempt to limit the amount of slip between the 2 axles at the diff. JLs with open diffs do this by the traction control system and applying the brakes at individual wheels. While they are not as effective as a locker for rock climbing they have advantages over lockers in other situations since they are not an on or off feature. It depends on what you're doing with your rig.

Yeah I suppose I am thinking more about a true Detroit locker as opposed to the truetrac or posi clutch style Detroit.

 

[Kevin Mojito]

I ran "posi" 44's in the front for many years. You will have to keep up on oil maintenance little more often. Oil additive for clutch pack. Other then that no issues. When I moved to 35's I rebuilt with the double beveled plates for high torque. Dana use to sell the high torque kits back in the 80-90's. I did notice the axle u-joints started to rust up. This would be more stress added from the high torque kit. Still never dropped a u-joint. Used for the same thing your talking about, snow running. For me it was snow and sand.

 

[djherdez]

TrueTracs are awesome but they don't make them for the new JL diffs AFAIK

They do now!!!! As of December 2022!

 

[Beungood]

correct. Im leaning towards just waiting until trutrac is out and ill just have to open the diff up again.

Do they plan on one for the Mojave? Ill any other LSD Locker work there?

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