5 ton lockout hubs

[73m819]

I am interested in a set as long as they work on the A2.

They will work on ALL the 5t front hubs, the 39, 809, 939 series, though you will have transfer issues with the 39 and 809 series

 

[Gunzy]

Ouch, that is way out of my range. I think most will see that out of their range. Some one better be putting a lot of miles on their truck to justify the expense. JMO

 

[patracy]

I had been following the other thread profo (I think that's his user ID) was posting about them. I was eager to purchase a set. But it'd have to be around $1500 mark for me to consider them. (Double/triple the cost of 2.5T hubs) I in no way discredit the amount of effort and work put into them. But for a truck I only rarely drive, I'll never see a return on fuel costs from it. I know cutting another $1K out of the cost of them is a tall order. Probably only achievable from mass production and casting.

 

[Jeep Nasty]

I'd be in for a set in the 1k ball park.

 

[Ddmk18]

Yeah I would go about $1500.

 

[KaiserM109]

I'd be in for a set in the 1k ball park.

Ditto

 

[74M35A2]

Ditto^2. $2500 is nearly half of what I paid for my truck. Roll em' for $800 per and you won't be able to keep them in stock. Where is all the money at in these? CNC should bring the cost way down, even for low batch volumes.

I'd pre-pay to commit. Were these confirmed to work on A2 (CTIS)?

 

[162tcat]

I'm with the other guys, $800-1k is far more reasonable. At $2,500 a few sets will be made then production will stop for good. Hope you never need replacement parts... At $800-1k lots will sell to us and the guys who use these on mud/4x4 rigs. You may even see them in the classifieds in the future. It may be time to shop around for the machine work.

 

[tobyS]

Oh yea...very nice workmanship. Premium materials.

Have you considered air operation or mounting on an intermediate or rear axle?

 

[Castle Bravo]

They will work on ALL the 5t front hubs, the 39, 809, 939 series, though you will have transfer issues with the 39 and 809 series

I'm sure MtnSnow and Ddmk18 are referring to CTIS compatibility. It doesn't look like it would work with the front CTIS arrangement on a 939A2.

 

[tobyS]

Here is an interesting thought on an 809 series. The transfer case is always engaged (except in neutral) and the front, while having the same gearing and turning the same rpm while going straight, has a 13/14 ratio in the transfer case. The front drive in the transfer case turns 13 times for every 14 times that the rear turns. Thus the sprag clutch...a one way clutch is used, to relieve what otherwise would be drive-line binding. In slippage conditions, the clutch holds and provides torque to the front. This clutch is very important.

Here is the point. If the front axle is not turning the drive line, like in the case of lockouts, the input on one side of that clutch will turn while the other side will not. Instead of it turning 13 times for every 14 that the rear drive turns, it will turn 0. That is making the sprag clutch see 13 times more wear and tear on the guts of the sprag (the elliptical cog) by stopping the front drive from turning, than if the axle is turning.

Unless I had a supply of sprag clutches laying around and like to change them, I would not use lockouts on an 809 series or any vehicle with the sprag clutch.

I could be wrong, but a properly functioning sprag is to be cherished.

 

[MyothersanM1]

Remove the air routed through the transmission twin poppet valve to the sprag declutching cylinder and the sprag will default to neutral. The front shaft will then be disconnected from both the transfer case and the axle. I believe there was an MWO applied to some M809-series trucks that installed an air switch to cut out the sprag. Corrections if I am wrong.

 

[Squirt-Truck]

The M39 series and the M809 series use the same case and yes it goes to neutral when the air is removed. There is NO position of the shifter that gives neutral, that is what the MWO was for. to relieve wear on the sprag.
Yes a properly operating sprag is to be cherished, they are far better than a direct connection unless the truck is totally off hard surfaces.

 

[73m819]

The sprag is a over running, one direction, automatic engaging clutch, in the 5t transfer (39/809) there are basically two over running clutches back to back, the internals in the transfer case have the front input (from the front axle rotation) turning 8% faster then the rears, when the rears spin (loose traction) there by spinning 8%+ faster, the over running clutch dogs are allowed to engage, driving the front axle, the over running clutch WILL STAY ENGAGED even after there is no rear spin till the load is taken off the clutch dogs (step on the clutch), this is WHY it is INPORTANT to release the load on the over running clutch BEFORE you drive on hard surfaces, you WILL break something if you do not.

So by using the front slectomatic hubs UNLOCKLED, the transfer WILL think the rears are spinning, engage the sprag, driving the third member, needless to say this will lead to a lot of UNNEEDED ware, and there is not really any way to get around this UNLESS you can find a NONEXESTENT 5t "REB" kit (never made). (A reb kit was a kit made by Memphis equipment that converted a DEUCE sprag transfer case to a manual shift front engagement transfer case).

Hope the above helps

 

[tobyS]

OKay there may not be a neutral on the transfer case (I sold the truck so could not check).

When I had my t-case out, if I recall correctly, there was not 3 positions for the sprag, but 2...either forward or reverse. There is no "neutral". It's going to turn (the transmission part)... cannot be disengaged.

The ratio 13/14 is 8% so we are saying the same thing. I'll put it another way. The internals of the sprag will rotate 8% between themselves going down the road normally and 12x that amount (100%) if the front is not turning. No way would I want that much wear in it, rubbing the little cams (oblong) against the turning member. I cannot see any way the locking hub works with a full time drive that has a sprag, without causing a wear problem.

Have deuce people had this come up, since locks have been available for some time? Do all (not A3) deuces have the sprag?

 

[Csm Davis]

Yes tobyS and squirting truck there is a neutral position in a 809 series transfer case, you have to use it for the rear body on a wrecker. MyothersanM1 is correct about the removal of air to the transmission poppets that engage the forward or reverse Sprague it will completely disengage the Sprague and allow the front to freewheel.

 

[tobyS]

Yes tobyS and squirting truck there is a neutral position in a 809 series transfer case, you have to use it for the rear body on a wrecker. MyothersanM1 is correct about the removal of air to the transmission poppets that engage the forward or reverse Sprague it will completely disengage the Sprague and allow the front to freewheel.

I must have had the sprague out 10x and cannot remember a neutral position that would allow a freewheel (of the sprague clutch). I always assumed it was in forward mode unless I shifted to reverse (and could hear the air from the shifting cylinder). I never recall doing anything to engage it or hear air shifting it while in forward...thus full time AWD. I must have missed something and wonder why I could not hear the air from going in and out (back to neutral) in forward gears, like I do shifting to reverse.

Is my point about turning made not valid if the sprague is in a neutral position? Turning with an 8% difference is less wear than turning with 100% difference (which will happen if the front axle is disengaged, not turning). Or does the sprague somehow not turn at all when in a neutral position?

Edit; I do recall a spring loaded piston for the sprague that might bring the cogs into a center position so it does not engage either the forward or reverse. In that case the entire unit is probably turning at the same speed and only the tangs of the shift mechanism or it's engagement ring would be a 100% different speed...which I don't trust since there are no bearings, but steel to steel. Thus it would wear, but at a different place (perhaps not as bad...thus the NWO to give manual control, which cuts off air to the engagement).

 

[Csm Davis]

Okay I believe that you are getting the idea on your edit, but you and the others worrying about wear, after a few rotations going down the road everything turns at or very close to the same speed the biggest advantage to the lock out hubs up front is less binding and mass to force up to speed.

 

[gringeltaube]

OK, back to the hubs, with a technical question:

There are no springs of any kind to be seen in the pics. Maybe the OP can explain to us if these hubs use a screw-type, positive engagement mechanism to move the sliding clutch gear, or rather have some sort of springs also, to shift- and hold the sliding gear in place. That is, when put into "LOCK"- and splines are not perfectly aligned the spring will just compress. Then when unlocking after AWD-use, and the gear eventually remained "torque-loaded", that spring would just extend until binding is relieved and said part was free to move.






Edit: Oops, guess I need better glasses: found the "missing link", way back in pic #3 !
That coil spring there basically answers my own question.




G.

 

[sweetk30]

also if the hub ever fails what is the default position ?

locked

or

un-locked .

lots of off-raod guys buy hubs that fail locked if it was to ever fail . helps get back home .