Detroit Locker Question

[cgtboy1988]

Hi all,
I recently picked up a pair of detroit lockers at a great price ($320/each after shipping) with the military seal kit for my M109A3. These were I guess surplus- perhaps from the marine deuces setup with them? In any event, I am considering which axles to stick em on and where to put lockout hubs. I figure the front and rear would be good with lockouts, allowing the mid axle to drive. I am wondering if the front needs lockout hubs to preserve good handling characteristics. My deuce has the sprag transfer, which means the input shaft to the front will always be turning, but it will only be receiving power from the t-case if there is a loss of traction on the rear, which would be a good time, I would think, for the axle to be locked so I am not terribly worried about that. But, what about in regular driving conditions? Will the detroit lock without any input from the drive shaft? After a search, I found somewhat contradicting answers to this. Some say the detroit is always locked, others say it is only locked with input from the drive shaft. If it is always locked- or locked until sufficient traction unlocks it- I will just grab lockouts for the front. That introduces a second potential problem. The sprag t-case does not usually transmit any power to the front drive shaft, because the front axle should turn quicker than the sprag front drive. If the sprag has to apply power to the front differential because the front wheels are not turning it fast enough, will that wear the sprag?
Thanks in advance for any wisdom!

 

[gimpyrobb]

Yes, they lock with power applied from the driveshaft. Yes, you will wear out the sprag T-case clutches with lock outs on the front.

 

[cgtboy1988]

Yes, they lock with power applied from the driveshaft. Yes, you will wear out the sprag T-case clutches with lock outs on the front.

Cool. I guess that means just stick the lockers in the front and don't worry about lockouts, as the lockers should not drastically effect handling when the t-case is not powering the axle.

 

[gimpyrobb]

I use de-splined axle caps on mine. I don't have a locker and do have an air shift T-case though.

Good news is, you can swap in an air-shift case in a day or two if your sprag goes bad.

 

[clinto]

These were I guess surplus- perhaps from the marine deuces setup with them?

I would very much like to see some pictures of your lockers.

The M44/G742 series only had one locker and that was the air operated model in the Norwegian M621 series of deuces. I feel very confident about this.

USMC lockers was a 5 ton thing and I don't think terribly common.

If you really have a detroit locker and it's US surplus, I think you have a V100 locker. Like this:

 

[cgtboy1988]

I would very much like to see some pictures of your lockers.

The M44/G742 series only had one locker and that was the air operated model in the Norwegian M621 series of deuces. I feel very confident about this.

USMC lockers was a 5 ton thing and I don't think terribly common.

If you really have a detroit locker and it's US surplus, I think you have a V100 locker. Like this:

The lockers are on their way to me as we speak, this is it



On another note, does anyone know if the wheels and axles spinning will make it back to the drive shaft through a locker? IE if I stick a locker in the front axle on a sprag T-case, would the T-case be spinning the drive shaft, or would the wheels be doing that work?

 

[clinto]

The lockers are on their way to me as we speak, this is it

I can't tell from that picture but I'll warn you: The V100 has larger, different spline axle shafts. Make sure to check this with your axles before install.

Also, eBay links are forbidden here, so I've edited your post and just added a picture.

Thanks

 

[cgtboy1988]

I can't tell from that picture but I'll warn you: The V100 has larger, different spline axle shafts. Make sure to check this with your axles before install.

Also, eBay links are forbidden here, so I've edited your post and just added a picture.

Thanks

My apologies and thanks. According to the Boyce website, these are 16 spline axle surplus, but more info than that is not available.

 

[w3azel]

Something you should think about is if your truck doesn't have power steering you should seriously consider it or place lockouts on the truck. Normal easy driving around on the roads you should be fine. Your lockers will do their thing and allow one wheel to spin faster when you let off the throttle and your sprag t-case won't engage the front axle. Now if you drive in the rain, a gravel road, snow, or just hit the throttle hard in a turn and that sprag T-case engages for whatever reason that steering wheel is going to whip itself straight so fast you won't be able to react.

I have lockers front and rear on my truck, along with power steering and lockouts. Now I have an air shift T-case so I only engage it when I go off-road but I did have a situation where I had to drive with my front axle on. Even with power steering it was the most terrifying time I had driving in town. It's not fun when a +12k lb truck fights to go straight when you're trying to go around curves with traffic.

 

[cgtboy1988]

Something you should think about is if your truck doesn't have power steering you should seriously consider it or place lockouts on the truck. Normal easy driving around on the roads you should be fine. Your lockers will do their thing and allow one wheel to spin faster when you let off the throttle and your sprag t-case won't engage the front axle. Now if you drive in the rain, a gravel road, snow, or just hit the throttle hard in a turn and that sprag T-case engages for whatever reason that steering wheel is going to whip itself straight so fast you won't be able to react.

I have lockers front and rear on my truck, along with power steering and lockouts. Now I have an air shift T-case so I only engage it when I go off-road but I did have a situation where I had to drive with my front axle on. Even with power steering it was the most terrifying time I had driving in town. It's not fun when a +12k lb truck fights to go straight when you're trying to go around curves with traffic.

Thanks for the feedback! I have air steering and have not yet experienced any of the thumb-breaking issues others have had (including when I turned off air steering after developing an air leak once) but I am thinking that, if the sprag engages and locks the front, it could be a much bigger issue. I was favoring lockouts on the front axle as well, but I just also worry that having an unengaged front axle would strain the t-case (as it would have to keep the drive shaft spinning all the time, not sure this type of t-case was built to do that). In any event, I have the lockers and they are officially on the list of things to install, but I am planning to get new tires and take care of the axles and wheels in one sitting, so it may be a while before I get to them. When I do, I am planning to install the lockers in the front and rear and put lockouts on the rear initially. If the front needs them, I will grab lockouts for the front later.

 

[gringeltaube]

.............I was favoring lockouts on the front axle as well, but I just also worry that having an unengaged front axle would strain the t-case (as it would have to keep the drive shaft spinning all the time, not sure this type of t-case was built to do that)....................

No reason to worry. In your case, driving with locking hubs unlocked (having a diff. locker or not)... 1) there will be no strain at all; 2) the front DS (+ differential gears + axle shafts) will spin all the time, yes. But instead of being driven by the front wheels, at basically the same speed as the rears, it will turn about 7% slower. While doing so, the only force that sprag clutch had to overcome is the inherent drag (resistance) of all internal front axle components, moving at said speed; 3) your T-case was designed well enough to run even in that condition - I'd say almost forever!



G.

 

[Eliteweapons]

While we are on the subject. I looked at lockers in the past but read alot of negatives about using the Detroit version in these axles which delayed me getting any. Anyone have any bad experiences with these? I was only considering getting one for the furthest rear axle. Any thought about that as well?

Thanks

 

[rustystud]

While we are on the subject. I looked at lockers in the past but read alot of negatives about using the Detroit version in these axles which delayed me getting any. Anyone have any bad experiences with these? I was only considering getting one for the furthest rear axle. Any thought about that as well?

Thanks

Any "Detroit Locker" style limited slip differential will be hard on parts, especially axles and side/spider gears. That's just the nature of the beast. They are the best and strongest of all the limited slip differentials except the "air-lockers". In my opinion the air-locker is the very best for a heavy truck like the deuce. It is also only "on" when needed. When you consider all the stress the normal rear differentials are under in a deuce (no compensator between differentials) when turning. Adding a "locker" is just compounding the stress. The problem with the "air-lockers" is price ! They are extremely expensive units ! If all I could afford is one Detroit Locker then I would install it on the forward rear differential. This area of the truck benefits the most from having both wheels turning with power when your in a sticky situation. This is also where most big rigs have their lockers installed when only using one.