Can someone explain what gets engaged when I lock my hubs

[vtboy51]

As I'm rebuilding my front end I'm realizing I don't 100% know which pieces actually lock my axle and hub together to engage the 4wd. I've attached a diagram to help explain what I think is happening. I assume as I lock my hub it pushes the "axle shaft sleeve" down the axle shaft and the teeth interlock with the teeth of the "inner clutch ring" and that is what locks axle and hub together?? If that's correct, what ensures they separate when I unlock the hubs?

 

[bax]

yes......

 

[jrwyant]

The "Pressure Spring" pushes the rest of the internals back out to disengage, when you rotate the "Actuating Knob" to the "free" position.

 

[vtboy51]

The "Pressure Spring" pushes the rest of the internals back out to disengage, when you rotate the "Actuating Knob" to the "free" position.

So the pressure spring pushes the inner clutch ring off the axle shaft completely? I assume this must be the case, since i don't see a way to force the axle shaft sleeve and clutch ring to separate when I unlock the hub.

 

[savage]

Here's a stock hub out of my 74.Like jrwyant said the large spring pushes the inner gear up to lock the hub and to unlock when you turn the knob, it pushes down on the two ears, they push down on the inner gear to unlock.

 

[Broncobowsher]

Second picture, the outer splines slide in and out for engagement and disengagement
First picture, top left part. The square cut cogs facing you, those mesh or unmesh for lock and unlock.

The spring forces the cogs to mesh together.
The knob and ramps push the cogs apart (and compress the spring).

 

[Quick & Dirty]

The spring forces the cogs to mesh together.
The knob and ramps push the cogs apart (and compress the spring).

And if the wheel hub has too much grease, old sticky grease, or the hub body is dented, the spring may not be strong enough to engage the cogs.

 

[vtboy51]

And if the wheel hub has too much grease, old sticky grease, or the hub body is dented, the spring may not be strong enough to engage the cogs.

Funny you mentioned a dented hub body, I've been trying for months to get the inner clutch ring to slide out of the hub . Either the grooves are dented or the hub is no longer perfectly round. At this point I'm giving up and bringing it to a shop to see if they have any tricks I haven't thought of.

 

[Steve83]

The "Pressure Spring" pushes the rest of the internals back out to disengage, when you rotate the "Actuating Knob" to the "free" position.

That's backward. When you turn the knob to "FREE", you're pushing the clutch INBOARD (away from the sleeve & ring) and compressing the spring. When you turn it to "LOCK", the spring pushes the clutch into the sleeve & ring assy., which is held in-place by the axleshaft snap ring (it never moves). It's not apparent, but the actuating cam body (the ring with 2 big teeth) reaches around the sleeve & ring, and only touches the clutch.

...I've been trying for months to get the inner clutch ring to slide out of the hub . Either the grooves are dented or the hub is no longer perfectly round.

After removing everything else, push the clutch INTO the hub, and look for rust or gummed grease that interferes with it sliding out. Use carb/brake cleaner to rinse out the gum, and then use a small punch the same size as the spline grooves to break up any crusty spots. It can take a while to go all the way around the hub (outer) splines, but when they're all clean, the spring should push the clutch out far enough to hook & pull it the rest of the way out.

 

[DirtDonk]

So the pressure spring pushes the inner clutch ring off the axle shaft completely? I assume this must be the case, since i don't see a way to force the axle shaft sleeve and clutch ring to separate when I unlock the hub.

Not quite, but not sure if you just worded it oddly or not.
The inner ring does not slide off the axle shaft. But it does slide off of (out of engagement with) the axle shaft sleeve. Is that what you meant?

Engaged and disengaged is only between the inner clutch ring and the axle shaft sleeve. Each will always stay engaged to their splined counterparts. So all longitudinal splines, whether on the axle shaft or the outer hub, stay engaged with something in the locking mechanism.
Locking and unlocking the axle to the hub takes place when the clutch ring and shaft ring move in and out in relation to each other to engage or disengage the square dog teeth. (If that's what that type of interface is called that is? I've always called them "dog teeth" but never heard from a machinist what they are for sure.)

As others have said, disengagement is all done by the actuating knob pushing on the two ears of the actuating cam, which pushes the clutch ring/gear inward and out of contact with the axle sleeve.
Engagement is done by the actuating knob releasing pressure on the actuating cam and the spring pushing outward on the inner clutch ring until the teeth line up and click into position.
Simple, eh?%)

One aspect of this design is that if the outer knob is ever knocked off (a very common thing back when 6" wide wheels were the norm) and the lockout parts exposed, the spring will keep the mechanism engaged and the truck in 4wd still.
The aftermarket hubs such as Warn and others will fail into the unlocked position if something happens.
With deeper dish wheels (negative offset) this is not as much of a problem. It can still happen on the rocks, or with aftermarket hubs breaking under pressure, but not as often as in the old days.

But either way, if the hub end is open and inner workings exposed, simply cover up the hole with a plastic bag and a rubber band, or a rag and a zip-tie, or whatever you've got. Since the wheel bearings are separate from the lockouts, you're still mobile and you just need to keep the dirt, moisture and whatever other off-road demons want to get in there and wreak havoc.

Paul

 

[vtboy51]

Thanks everyone for the info, it all makes sense now.