Front diff lubing vs freewheeling hubs

[cranetruck]

Freewheeling the front will keep the differential gears from being lubricated.

Nothing is turning, any thoughts on that?

 

[Recovry4x4]

Most vehicle manufacturers recommend locking the hubs for X number of miles each month. Since I'm lazy, I just engage 4x4 and leave the hubs unlocked. Nets me the same results. Honestly, even followin the mfrs directions doesn't get the front axle hot enough to ward off the condensation. I've never looked that closely at the -10 for the CUCV but I had a civilian K-30 that I bought in 1986 and it had the instructions right on a sticker on the visor. Off tangent a bit, I also had a 1962 GMC panel truck that was factory 4x4 with hubloks. Had a similar sticker right on the inside of the top.

 

[cranetruck]

Is there anything in the instructions to that effect when you buy freewheeling hubs from, say, Interagency Motor Pool?

 

[Rattlehead]

Condensation will build up in the diff when not used. I once drained a considerable amount of clean water from a pickup's front diff, and I am pretty sure it was not from swimming.

Same as Kenny, with my pickup I drive with 4x4 engaged and manual hubs unlocked, or vice versa, on occasion.

 

[Gatnom]

<SPAN style="COLOR: white">[3]When I’ve had the opportunity to drive 4wd vehicles without the tranny floor pan, the front drive shaft always turns despite the hubs being out.<SPAN style="mso-spacerun: yes"> I’ve attributed it to drag caused by the grease in the hubs.<SPAN style="mso-spacerun: yes"> This coasting of the assembly would keep the ring and pinion oiled well enough to prevent rust.<SPAN style="mso-spacerun: yes"> I think the idea of working the 4wd is more to exercise the clutch pack in a limited slip diff. to prevent its friction disks from sticking. <SPAN style="mso-spacerun: yes"> Using the 4wd would generate a little more heat, but I, like Kenny, think your hard pressed to make enough heat chase off a large amount of condensate (Although you seldom find much moisture in any gearbox of a regularly driven vehicle so maybe there is more heat there than we think). <SPAN style="mso-spacerun: yes"> I never noticed any rust in the diff of a vehicle that is driven regularly whether the hubs are locked in regularly or not, but have seen major rust damage to ring & pinions, transmissions, etc. that have been left to sit.<SPAN style="mso-spacerun: yes"> The lube runs off and dries/evaporates and the condensate attacks the exposed metal.<SPAN style="mso-spacerun: yes"> The areas submerged in oil show little or no damage.<SPAN style="mso-spacerun: yes"> Something to keep in mind the next time your after that axle, transmission, or transfer case that’s been sitting for the last 20 years.<SPAN style="mso-spacerun: yes"> It pays to pull a cover and peek inside before cash changes hands.<SPAN style="mso-spacerun: yes"> Dave <SPAN style="mso-spacerun: yes"> <SPAN style="mso-spacerun: yes"> [/3]<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

[SixBuy]

Interesting! My 1/2 ton 2001 Dodge 4x4 service says change the front diff lube. I guess that's because the left axle is one piece (no hubs) while the right is split with a disconnect. Seems wrong because the left axle is constantly engaged - kind of like driving the jeep with one hub locked - a definite no-no!

The 3/4 ton trucks don't have the right axle disconnect; they rely on hub disconnect. I've often wondered why the same drive train in a 3/4 ton seems to get a little better gas mileage, despite the extra weight. Is it the drag of the left Front axle? What am I missing?

I've always heard one-axle-engaged puts undue wear one the spider gears due to the constant full speed differential action. Does that occur when you pull one rear axle on a deuce?

 

[rdixiemiller]

You actually are not doing anything to the spiders running with one hub unlocked, as long as the drive shaft is engaged. That is how the newer vehicles are set up. Unlocking the one axle eliminates wheel hop and bind when turning. With the driveshaft turning, and one hub unlocked, the spiders are only turning when you make a turn.

 

[SixBuy]

Now dadgumit you're gonna make me rollout the floor jack and see for myself! I always thought that when the xfer case was in 2H the front driveshaft was disengaged and if it turned at all it was from the drag of the left axle. I can see that disconnecting one axle wil get rid of "K-nuckle K-nock" at the expense of differential action....

Now on the deuce that's not an option because the xfer case is only High/Low. Come to think of it it doesn't even have a Neutral, does it?

 

[cranetruck]

Hmm....it does have a neutral, that's how you run the transfer pto.

 

[SixBuy]

I had to go climb up in the cab and see! Yep there's a detent in the shift travel even though the dash shift plate only says "up/high - down/low". Idle curiosity - do they have a different dash plate for trucks equipped with xfer PTOs? Mine has a tranny PTO for the front winch.

Unrelated - I've spotted a new HIAB coming up in surplus. Any idea what one is worth? Or how much it weighs?