4 wheel drive problems need expert

old · Feb 4, 2011

My Chev 4 wheel drive truck let me down today. 1980 Chev with front lock outs. One if not both the manual lock outs would not lock in. So #1 how do I figure out which one is not working as it should and then #2 what do I look for to fix it. This summer I had to replace the wheel bearings on both sides so figure there is part of the problem. On one side the lock out bar does not lock so if reads the correct way could it be as simple as turning the outer ring one bolt hole so things line up.
Thanks

Anonymous-0 · Feb 4, 2011

With tr. in neutral not running, wheels block, and keys in your pocket. lock both hubs. then craw under tr. with flat screw driver, try to turn axle, the one that truns is the one with bad hub. may not work if you have posi track. hub may have ice in it or gummy grease.

Anonymous-0 · Feb 4, 2011

Should be able to put the transfer in gear and raise the front end and turn the wheel when the hub is locked. If it doesn't turn all the way thru and turn the driveshaft, there is the problem. Been a long time, but I remember the military vehicles from that era were not real reliable. Pull the caps and look for anything broke.

Dave

Anonymous-0 · Feb 4, 2011

(quoted from post at 18:34:21 02/04/11) With tr. in neutral not running, wheels block, and keys in your pocket. lock both hubs. then craw under tr. with flat screw driver, try to turn axle, the one that truns is the one with bad hub. may not work if you have posi track. hub may have ice in it or gummy grease.

That's the sissy way of doing what I said :roll:

JayinNY · Feb 4, 2011

Old/Rich, I had a simular prob on my 84 chevy, had dad get in and put it in gear on ice, I watched the front u joints to see which was spinning, the left was the right side wasent. I squrited oil around the manual lock hub and drove the truck around, seemed to have freed it up and it worked after that. Sounds primitive but it worked for me. J

JayinNY · Feb 4, 2011

Oops, sorry, dident see that you took it apart, ya you may have to unbolt the 6 allen bolts and re aligen it, I think it is 6 bolts, if memory serves me right. Hopefully you put it back together right inside.?? Been awhile since I worked on mine!

cadet trooper · Feb 4, 2011

If I remember right Chevy only made all wheel 4 wheel pickups in the 74&75 2500 model and the 1980 & 1981 1500 pickups in the automatic transmission models which had no locking hubs I tried installing locking hubs in the 80 model to save gas and I discovered if I unlocked the hubs the truck would not move and I found out the truck runs off of the locker system so if they are unlocked it will not move period. Just a thought. They were KA trucks because they would throw mud from all four tires when giving them heck.I don't know about the manual transmission models just never had one.

GordoSD · Feb 4, 2011

Rich, Do you have a heated garage there. Drive it in and let it set overnight.
If you DON'T have at least a small one stall heated shop/garage, you need to sell/swap/trade a lot of stuff you don't need so you can build one. No reason for a good mechanic like yourself to NOT have a place to work year round. I'll bet we could get enuff yters to come down and put it up if you let go of enough junk to buy the materials.

Gordo

Anonymous-0 · Feb 4, 2011

Cadet, my 77 K-10 was like that, fulltime 4X4.. Stick had 5 positions, HiLock, Hi, Neutral, Lo, Lo lock. No locking hubs.. Used a lot of gas, though..

ericlb · Feb 4, 2011

old, you'll have to raise each front wheel off the ground and lock the hub, if the u-joint in the axle shaft isnt turning its not locking in, what kind of hubs does if have? if warn,carefully remove the 6 hex bolts from the chrome lock out, those little suckers will break easy, make sure both snap rings are in place, also that the "cams" on the plastic lock handel are there and when turned will push the metal ring inward and lock the hub to the axle, if you can manuely push the outer part of the aluminum hub over the inner with a screwdriver and achive lock, the problem is right in the handel end, as long as both inner and outer snap rings are there , hope this helps if pushing the outer aluminum part over the inner part on the axle does not achieve lock it either has a ring missing, or the aluminum outer piece is damaged

old · Feb 4, 2011

Manual lock out and a 4 speed transmission and a cast iron transfer case this truck if heavy duty old school

JDemaris · Feb 5, 2011

I don't know what you actually have for hubs, but I suspect they are NOT full manual. You've probably got the cheap spring-loaded Warn style hubs that are commonly now called "manual."

Full manual hubs usually have no plastic anywhere and when you turn the dial, they force engagement. Sometimes you have to rock the truck, to line up splines, to get the dial to turn. Common in the 60s; not so common anymore.

Later Warn-style hubs are spring-loaded. NO positive engagement. They did that so you can always turn the dial without having to rock the truck back and forth. When you turn the dial into "lock", a spring pushes the parts into engagement-ready position. Then when you move the truck, and the parts line up, they snap into place. So, they can get ice inside and get stuck. When that happens, the dial reads "lock" but the hub is still in free-wheel.

If not frozen, and the cheap hub, your plastic cam might of come loose inside. It's only held in by one self-tapping screw. But if that happened the dial should pull off.

I assume you've got the big internal ring installed in the hub-housing, and the small external ring installed on the splined axle stub?
You would of removed them both to get to the wheel bearings.

IaGary · Feb 5, 2011

I don"t know if it worked when it was warm, but is there a chance that it has a little water in there and it is frozen.

I had one that would freeze. If you could drive it a bit in two wheel it would seem to warm enough to lock in.

Then don"t unlock it till spring or take it apart and clean it out.

So you might try warming it.

Gary

old · Feb 5, 2011

Yep got the spring type lock out and wondering it the outer ring that has the words free and locked need to be lined up when I put it all back together to work. the side the lock out lines up as it should and the other side it doesn't an wonder if I go it to line up if that would fix it or not

old · Feb 5, 2011

I have a shop with a wood stove but it is where the snow is the deepest and no way to get the truck in it at this time. Plus I did not cut any wood for it and the wood I do have for it is out where I can not get to it either. Had not planed to us the shop this winter

Billy NY · Feb 5, 2011

Rich, if I am not mistaken didn't that truck have Spicer hubs from the factory, though they could have been changed later, I have an '80 K-10 that had em, thought they were OEM, but they were changed out as something went awry in there, used to have em serviced too, it's been a long time since I have seen one apart, those spicer ones seemed to be good, never any trouble locking em as I remember.

JDemaris · Feb 5, 2011

The polarity shouldn't make any difference. That cap can be rotated and stuck on three different ways - and it should work fine with any.

I just had mine apart on my 79 - but with the opposite problem. Not staying dis-engaged. I had to pull apart and clean the plastic cams inside. Now they work fine.

I'm having trouble with my 78 plow truck not staying in 4WD but the problem is the transfer case. It has the 203 that was converter from full-time to part-time 4WD a long time ago. Now it's jumping in-and-out.

I assume you've got the gear-drive, cast-iron 205 in yours?

smallercrawler · Feb 5, 2011

Hi Old, not an expert but BTDT, I had '80 Blazer, 4 speed /Spicer hubs did same thing on 1 side after wheel bearings job. If I recall correctly (15 yr. ago) under the lock hub with several allen bolts there is an internal spline with two grooves about 1/4" apart for an internal lock ring. I had put the retaining ring in the wrong groove and it needed to be in the other groove to control end play in mechanism when locked. Don't recall which was correct now. Discovered problem in a mudhole a mile or so from help. HTH.

old · Feb 5, 2011

Yep it is the cast iron one and boy is that thing heavy. Did the clutch a couple years ago and had to rig up a way to slide the tranny back and out of the way but not have to try to lift it by hand. I guess here in a little bit I'll go out and jack up one wheel at a time and see if I can figure out which one is not working like it should. I know the chains that I have on the back will help but would prefer to have 4 wheel drive

JDemaris · Feb 5, 2011

My plow truck with the 203 transfercase has chains on all four wheels. When it pops into 2WD, it's useless.

Eric in IL · Feb 5, 2011

Why do you need to jack it up?

I would put transfer case in 2wd or neutral, lock in hubs, then crawl underneath and turn front driveshaft by hand. While turning look at the u-joint on the inside of each front wheel. The one that is turning is the side that is not locked.

Of course this method won't work if you have the gears in the front differential welded up.

Anonymous-0 · Feb 5, 2011

That's the way I'd do it too.

old · Feb 5, 2011

Oh so you would want to lay in snow to do that. At least by jacking it up I can stay out of the snow and also check for other problems which I did find but will post that in just a bit

old · Feb 5, 2011

If it was summer I might do that but with snow on the ground and not being able to get it to the shop I did in fact jack it up. Sure glad I did because I found other problems which I'll post about in a few

old · Feb 5, 2011

Ya funny how a 4 wheel drive in 2 wheel drive is useless but a 2 wheel drive truck if you add the right weight in the right place will go a lot of places

4 wheel drive problems need expert

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