Selectable Hubs or Not?

[W_A_Watson_II]

Back when I bought the Mile Marker Selectro Hubs for the M37, I thought they had a life time warranty, but that is not the case.

I've had them repaired once under warranty, and again just now out of warranty. The first failure was because of the O-Ring, this failure was because I stripped the teeth off the internal component.

I ran the locking hubs as the week point (fuse) in the front, to help prevent breaking a front axle. Well, that didn't necessarily work as planned since I did explode a Tracta Joint. That might have happened as a result of the Hub going first on the opposite side, and when the Locker was engaged (while not in a bind/load), all the power went to the wheel I broke the joint on. Once I knew the hub was broke I installed the drive flange, but the damage was probably already done.

So now for the question. Should I leave the Drive Flanges on and run the M that way as it's almost exclusively a trail truck now, or should I re-install the Selectro Hubs? I like the idea of the hub being the fuse, but if they break too easy (repairs are slow and cost), and I don't catch it and cause more axle breakage, should I leave them off?

Merry Christmas,
Will

[712edf]

While I can't answer your question, I can pose another one that might get those creative engineering juices flowing. Would it be possible/feasible to introduce the "weak link" at another point within the drivetrain? It is my understanding that PTO winches have a shear pin somewhere within the system to prevent damage to the more costly components in the event of an overload. Could a driveshaft be designed in such a way that it breaks (actually shears) without really breaking, but coming disconnected, at least to the point where power flow ceases from one end to the other.

Take a look at farm impliments, they are loaded with shears pins & other features to allow for controlled breaks (weak links) within the system. Some way to take the break, yet keep things attached at the same time surely can be thought of. I am using the terms "attached" and "connected" to mean 2 separate things here. For instance when a selectable hub is in the open/unlocked position, it is attached but not directly connected to the axle shaft.

Just pondering.

Bucky

[mannyc]

driveline savers

heavy trucks have torque tubes on the driveshafts. they cut the driveshaft in half. they weld flanges on either side of the cut. the insert a smaller tube and weld the tube to one half of the joint. they assemble the flange with bolts that act like fuses when the desired breaking point is reached. might be an option.....

[MasterYota]

I don't know if these could be adapted to fit your hubs, but it could be an option worth looking into....

http://www.bc4x4.com/features/2000/sema/sema-22.jpg

[712edf]

heavy trucks have torque tubes on the driveshafts. they cut the driveshaft in half. they weld flanges on either side of the cut. the insert a smaller tube and weld the tube to one half of the joint. they assemble the flange with bolts that act like fuses when the desired breaking point is reached. might be an option.....

This is exactly what I had invisioned. Never seen one though, glad to know it exists.

Bucky

[Gordon Maney]

If this is just a trail truck and is trailered to the site; I would suggest just using the drive flanges.

[Chris Olson]

power train savers

These are the driveline fuses I have seen
http://www.sonnax.com/powertrain.php

[Deathdeelr]

Now that is the coolest add on I've seen yet.

[Keith in CO]

drive hubs

. . . Should I leave the Drive Flanges on and run the M that way as it's almost exclusively a trail truck now, or should I re-install the Selectro Hubs? Will

I keep a set of flanges under my seat and just run them when I am wheeling hard because I know my locking hubs are just too exposed to risk. One less thing to deal with when negotiating obstacles. Also, if I leave a selectable hub on - tempting fate don't you know - and break one on the trail (happened last Sept), I can bolt up a flange and keep going. I really like being able to disconnect the hub from the axle shafts, diff and front drive shaft when running down the highway enroute to the trail, and if I break a front axle shaft, I want to be able to drive the truck without turning the axles.

Not convinced about hubs being a dependable weak link because the stock front M37 and FFPW axle shafts are so wimpy that I figure I can break one no matter what hub I am running. I've also seen people break both hub and axle shaft at the same moment.