considering manual hubs

[flomulgator]

So I have a "new" (old) set of axles on the truck and one of the auto locking hubs is going bad (looks like poor maintenance). I can't find a single part for sale out there in internet land. Now I REALLY don't like the idea of getting out of the vehicle in the driving snowstorms in traffic that I deal with regularly and that's why I've always preferred the idea of autos to manuals.

But now I read that you may be able to leave a manual hub "locked" and just switch between 2Hi and 4Hi at will? And that all it does is cost some fuel mileage from spinning the front driveshaft? I don't have experience with manuals, so I need some help verifying this.

1. Does running a "locked" manual hub in 2Hi at full speed (75mph) on dry pavement for a 100 miles or more pose any danger to the system?

2. On the other hand, does anyone have any clue where I can buy an auto locking hub or how to service or repair a failing unit? (it's not disengaging properly).

Thanks for any advice!!

[DmaxMaverick]

I'm sure parts are available, but I haven't looked in a couple years. Take them apart and get a look inside. They may just need a good cleaning and some lube (silicone grease). Short-shaft bearings can also make the hubs act up (the shafts don't rotate true).

I like manuals, and there's no problem leaving them locked full time. The mileage hit is minimal, if noticeable. Depends on your current driving habits. My old trucks with manuals stayed engaged most of the winter (and some of the summer when I forgot unlock). If you decide to switch, I like Spicer or Perfect Circle hub lockers. Warn used to be OK (not as good as Spicer or PC, ever), but they've gone to mostly plastic assy's. All metal is better when the conditions get really bad, as I've found the plastic cuffs would bind (very hard to turn) when really cold, and didn't feel as "sure" engaging or disengaging. Silicone grease is the key with any of them, including auto lockers.

[flomulgator]

Thanks Dmax! As soon as I got these axles on the truck (maybe 2000 miles ago) I pulled the auto hubs to inspect them for obvious damage (none to my eye) and regrease them. However, since it just looked like heavy grease I simply replaced it with Mobile 1 synthetic grease. Bad idea?

Pulled the cover off the left one which is now acting up to inspect it and all the grease was brown, less viscous, blown all over the place, and smelled heat affected. Did the same to the right and the grease was still packed and red like I first put it in. Repacked the left one and it's at least running in 2Hi okay now.

Could this just be a wrong grease problem or should I start checking the short shaft and bearing?

Also, thanks for letting me know about the manual hubs, if I can't get these to work reliably I'll probably pick up some Spicers.

[Robyn]

I have had rigs with the auto lockers and when they were new, they worked.

This is about all I can say. They are like all the rest of the so called labor saving convienience items that the manufs bolt on these trucks.

Missy's recipe for success.

Carefully remove the auto lockers, place them in a heavy plastic bag and place gently in the garbage can for pickup, taking care to seat the can lid tightly so the little beggars can't get out.

Install a set of Warn manual hubs and sit back and relax.

These hubs are the best of the best and rarely if ever give trouble.

You can happily run the front end at road speed, and truth be known, its good for the gear box to be turned every so often anyway.

As Maverick mentioned, the mileage hit is minimal.

My prefered Modus operandi is, if the weather looks threatening, to twist the hubs in while I have the convienience of time on my hands (before hitting the big slab) then a casual flip of the lever is all thats needed.

When the weather is going to get Blistering cold and snow is likely, just flip the hubs in and leave them in.

In very cold weather (below 20F) the grease can get so hard that even the manuals can get cranky and not want to turn. Now below zero temps are a sure thing for stuff not wanting to work.

Keep it simple.

The 94 Burb we had always made me nervous as the front end was locked in via an electric Solenoid. Ya never knew if it was going to work or not.

I like to leave the things in 4x4 when the weather requires it. Just come out, get in start up and its gonna work.

I have seen a few folks that waited until they were stuck to try and flip the hubs in.. "BAD PLAN"


Just Missy's thoughts on the subject.


Yesssss, my 89 K5 has a set of lovely "U twistems" by Warn :D

Now if this Girl had really pretty painted nails, maybe she would not be willing to get out and turn the hubs, but that ain't the case. ;)


Missy

[DmaxMaverick]

Sounds like the left hub lost a seal. Could be inner/outer hub or short shaft seals. M1 grease is good stuff, but isn't nearly as water tolerant as silicone (which is why I recommend it, and it's slicker than snot at -20°). If the hubs are locked (and your tire size and axle ratios match), you can shift 2hi-4hi and back at any speed because the TC gears are at matched speed all the time (don't do it while in a turn).

Robyn likes Warn, and that's OK. Warn isn't a bad product, but they are only 1/2 as robust as the Spicers. Warn is adequate for most uses, at best. I've replaced a BUNCH of these, and the Spicers (Perfect Circle) last twice as long, and give less trouble when you need them most. Good seals and silicone grease will keep either brand working as well as they can. Don't forget the idler bearing. It needs some grease, too.

If you don't know when it's been done, consider a full service of the front axle. I used to be able to get a Fel-Pro "front axle service kit", which included all the short-shaft seals, bearings, retainers and gaskets for both sides, including the axle tube seals. The short shaft is a full-floater (floats in the side gears in the diff, and on the bearings inside the spindle), and is hardly ever touched during a full service (4x4 specialty shops do, dealers and general shops don't). You can't see all the little parts unless it's fully disassembled. You can also get a close-up look at the U-joints while they're out. It isn't a bad job at all, and you'll feel better afterward knowing it's all fresh after decades of abuse.

[flomulgator]

Alright Dmax, I've searched up and down for Spicer hubs that are for this axle and not a Dana. Do they still make them? Any idea where I can find them?

[DmaxMaverick]

Spicer and Perfect Circle is a Dana product brand. They make parts for other axles, not just Dana. I'll see what I can come up with.

[DmaxMaverick]

Looks like Warn 20990 may be your only choice right now. I didn't find any Spicer/PC in stock. I haven't shopped for them in a while. www.summitracing.com has the Warn hubs for about $100. There are some listed on Ebay, but they're more $$. Go figure.

[flomulgator]

I was kinda thinking that they might not be selling them anymore, looks like that's the case. I'll get the "premium" ones which have all-metal construction. I see that summitracing.com site has a brand I haven't heard of called Rugged Ridge. If you think those are good lemme know, otherwise I'm getting Warn Premiums from LMC Truck, who has them the cheapest and who I am a fairly devoted customer of.

I'll look around for a Fel-pro kit too. Any heads-up appreciated of course :)

[DmaxMaverick]

I have no experience with "Rugged Ridge". I don't know anyone who has. Reason enough for me to stay away from them, for now. I like LMC Truck. I didn't think to look there, this time. I usually do. Summit is usually fairly competitive, and has a wide selection. Good luck with the Fel-Pro kit. I haven't shopped for them in a while, either.

[flomulgator]

Slow and steady. Warn Premiums are sitting in the garage, now I'm working on the seal part. Funny, when you search the interwebz for "Fel-Pro axle service kit", this thread is pretty much all that comes up as a result. How circular!

So looking at Summit Racing I see this axle seal:
http://www.summitracing.com/parts/AXT-5131/
and this wheel seal:
http://www.summitracing.com/parts/AXT-471271/

Looking at LMC truck they have a lot of individual parts I'm not familiar with. I see a Spindle Seal, a related Oil Deflector and Axle Shaft Bearing, Seal, and Spacer.

Which of these parts do I need to keep water out of the hub? Also, should I replace the axle U-joint while I'm at it?

[DmaxMaverick]

Slow and steady. Warn Premiums are sitting in the garage, now I'm working on the seal part. Funny, when you search the interwebz for "Fel-Pro axle service kit", this thread is pretty much all that comes up as a result. How circular!

So looking at Summit Racing I see this axle seal:
http://www.summitracing.com/parts/AXT-5131/
and this wheel seal:
http://www.summitracing.com/parts/AXT-471271/

Looking at LMC truck they have a lot of individual parts I'm not familiar with. I see a Spindle Seal, a related Oil Deflector and Axle Shaft Bearing, Seal, and Spacer.

Which of these parts do I need to keep water out of the hub? Also, should I replace the axle U-joint while I'm at it?

The first link appears to be the axle shaft seal, which seals the axle tube (to diff) inside the knuckle. The second doesn't list the size, so I don't know which it is. Perhaps the wheel bearing/hub seal, which fits the hub (and captures the inner bearing). The others you list are all required, and perhaps others not listed. I'd have to look at the drawing (can't find mine). Contact a local 4x4 shop. They should be able to source all you need, or tell you where to get them.

[flomulgator]

http://img819.imageshack.us/img819/2815/img2187kp.jpg

[DmaxMaverick]

Looks good and they should serve you well. I thought the Warn Premiums were extinct.

[Robyn]

Same set that I have on my K5

Love them.

My normal modus operandi is, when the weather is at all sketchy, to flip in the hubs.

If the weather is dry, it only takes a second to unlock the little critters.

Do it before you get in the truck or at the coffee stop, fuel stop ???

Myself, I just feel far better knowing that when the hubs are twisted in that the thing is going to work when I yank the lever.


Just a FYI
Back in the mid to late 70's when the NP203 Full time T case was the hot ticket the front axles had power all the time no matter what the speed.

So driving with the axle spinning is not a real biggy, and certainly will not hurt it one bit.

I really wish that the NP 203 system, or something similar would be brought back.
This was IMHO the best 4x4 setup ever made.





Looking good


Missy

[Hooptybass]

I really loved the 4x4 system on my 90 Jeep Comanche . It had the jeep
command-trac system there wanst a hill around i wasnt afraid to climb in 4wd low in 1 gear on the 5 speed .. If memory serves it locked all 4 wheels up and it would go like hell in he mud or whatever you threw its way

[More Power]

Cupla things....

Back in the 1980s/90s, a friend of mine (who owned a service shop) drove a Ford F150 4x4, and left the front hubs engaged all the time. He said the front shaft U-joints lasted longer and there was just a minor hit to fuel economy.

That said, I know that unless the front driveshaft is balanced perfectly, it'll introduce some vibration and noise at freeway speeds that you can feel/hear in the cab. Personally, I'd rather replace a u-joint every few years and experience a quieter ride. And, I don't like turning stuff that doesn't need to be.

Jim

[arveetek]

Regarding the front axle being engaged all the time:

Jeep got rid of the locking hubs a long time ago, and now the front axle is "live" all the time, with the front driveshaft spinning at all times, whether the transfer case is selected for 2WD or 4WD. When you shift the transfer case into 4WD, it simply locks the front driveshaft to the rear. Result: instant 4WD! No waiting around for a central axle disconnect to engage....

That's one thing I really like about my Jeep (1997 Wrangler TJ): as soon as I pull the lever up on the transfer case, I'm in 4WD ready to blaze trails. If I want to go back to 2WD, just push the lever back down. No waiting time needed.

By having the front driveshaft spinning at all times, it allows you to shift into 4WD on the fly as well.

Casey

[Robyn]

The factory stuff had the shafts ballanced really well. The issues start after rigs get messed with in the field and folks repair/rebuild shafts or do other mods.

Most of the earlier GM stuff had a CV joint on the front drive shaft, and this made things very smooth.

Sadly once the CV joints wore out, many folks would replace the shaft with one that had simple single joints on both ends of the shaft.

Once this was done, slow speed off road work was fine, but higher speed highway running would many times see some bad vibes show up.


Seems that the engineers can't make up their minds on how these 4x4 systems should work.

From part time to full time, then back to part time, then back to full time, then run the front end all the time???????????????

Yank a lever, push a button, never happy.

Myself, I like a little lever to pull and hubs on the front on a part time system.

I still loved the days of the full time system such as the NP 203 cases with the single shifter on the floor.
High
High loc
Low
Low loc

Pretty simple and very reliable.

Missy

[flomulgator]

Okay so this is odd. Took a long road trip to for christmas. hubs were locked, 4wd went in and out, truck reversed, then hours on the road. No vibes, but pretty bad fuel economy (however that could be a number of things).

Then I go wheeling though the snow. Pull back on the highway, keep it in 4 hi due to snow, and start getting faint vibes at 40-45. Pull it out to 2, then hit the freeway. Vibes get bad at 65. Pull over, unlock hubs, vibes disappear. Never had the chance to reverse, which seems the only difference between these two experiences.

Q: Does reverse affect something mechanical w/ manual locking hubs?

Q: I got U-joints on an '86 10 bolt front axle. Did this use to be a CV joint axle?

Q: How do I fix this? Balance axles? Lube something? This is gonna be a pain tomorrow in the weather driving 8 hours through mountain passes and long dry stretches, getting in and out of the vehicle just for the hubs so that I can drive freeway speed. I'll make do tomorrow but this kind of operation is exactly what I wanted to avoid when switching to manuals.

[DmaxMaverick]

This is not uncommon with helical gears (diff and TC), and the reason for backing up. Unlocking the hubs relieves the load from the drivetrain, allowing the gears to disengage. You can do this by unlocking only one hub, or backing up, or driving a distance with some on/off loading. Moving the TC shifter is passive, meaning it only "suggests" the desired gear range (2H/4H). The compulsory "back up" is specifically related to the auto hubs, which are also loaded helical gears.

[flomulgator]

So basically I was still stuck in 4hi then?

It seems then that I could leave the hubs lock but reverse it like when I had the autos and it would unlock the system? How do I do effectively do the "on/off loading" instead?

Also, the vibe at speed is worse than when I had autos and would take it from 4hi to 2hi on the freeway and sped up.

[DmaxMaverick]

The TC should disengage (on the fly) over a short driving distance (mile or so/less), regardless. If it isn't, then something else is wrong. The load/unload is nothing more than acceleration, then deceleration. A couple series of this should unlock it. You may also consider measuring your tire diameters (roll out). If they are off significantly, it can cause a continuous condition of drivetrain loading, which can prevent unlocking. Using synthetic lube in the TC also helps.

[flomulgator]

Okay it sounds like I'm stuck in 4hi then.
Definitely did the load/unload thing (highway version)
All 4 tires are pretty new, purchased together
Full synth all around
TC case may be low though as rear driveshaft seal leaks. Could this be the issue?

[DmaxMaverick]

Okay it sounds like I'm stuck in 4hi then.
Definitely did the load/unload thing (highway version)
All 4 tires are pretty new, purchased together
Full synth all around
TC case may be low though as rear driveshaft seal leaks. Could this be the issue?

Ding..ding..ding.... You betcha!

If it was low enough, for long enough, it may have burned off the shifter fork bushings, which exaggerates the sloppy shift characteristic. Which transfer case (round tag on the rear case half), and what fluid?

[flomulgator]

Ah thanks for the resolution Dmax. I knew I should have topped that off before a trip in which 4wd was going to be seen, but I ran out of time, motivation, and supplies the night before I left. I have no idea what my shifter case is but I'll check next chance (not before I drive home though) based on your description.

Will also need to check on the fluid but Redline 90w-140 would be a good guess.

When I drive through the passes tomorrow I'll really try to give the shifter hell :D

[DmaxMaverick]

The TC should be serviced with ATF, in almost every case (the reason I ask for the TC model). Using heavy diff/lube oil will cause shifting issues (and premature failure), when ATF is called for. Redline ATF is good stuff, if that's what you have.

[flomulgator]

I was just guessing as I don't have my records here in vacationland, I almost certainly used ATF if thats what it called for; I take my lube seriously. The Redline part is probably true though.

I think the underside is stained red too so that would make sense. Stupid rear seal. Stupid old truck. If it weren't for the help of you and other people on this site I'd have given up on the beast years ago!

I like to think that if it I'm not fixing something then I'm not learning anything. At least that's how I stay positive.

[DmaxMaverick]

......I like to think that if it I'm not fixing something then I'm not learning anything. At least that's how I stay positive.

No doubt! Unfortunately, it seems I've "learned" a lot more than my fair share....

[a5150nut]

No doubt! Unfortunately, it seems I've "learned" a lot more than my fair share....

These old trucks also give a good lesson in patients and understanding.