Transfer Case "Doesn't work"?

[bruss01]

Hi gang. I just bought a 1978 terra 4x4 pickup, 345 engine, automatic transmission and all original everything. Previous owner told me the 4wd "doesnt work" and that the owner previous to him "disconnected it" somehow. Wtf? He didn't know much mechanically so it was pointless to try to get more information from him. After trailering it home, I wanted to test it. I go to turn the hubs (which manual says should only ever be turned by fingers) and see what look like plier marks on the hubs. Trying to turn the hubs with my fingers revealed why there are plier marks, it just wouldn't budge. The 2wd seems to work all right, btw.

Can anyone offer some steps to take to determine just what is meant by "disconnected" and how to find out what is wrong (I'm assuming a transfer case or hub issue) in a logical manner? I have basic tools and basic skills, never did any work on an axle or tc before, except changing fluid, but there's one way to fix that, right? I want/need to do all I can on this project truck myself for $$$ reasons, but there are cases where it's cheaper to bring in an expert. Recommendations?

 

[Mark Ashford]

First thing to do would be take the hubs apart. Easy to do with some basic, simple tools. Search hear and/or binderplanet.com to get some step-by-steps.

Then crawl underneath and look at things. Are there driveshafts front and rear, are they in good shape. Does the t-case lever attach to the t-case, is there anything obviously missing. What happens when you try shifting the t-case?

Start exploring and see what you find. Report back, take pictures.....

 

[Michael Mayben]

hi gang. I just bought a 1978 terra 4x4 pickup, 345 engine, automatic transmission and all original everything. Previous owner told me the 4wd "doesnt work" and that the owner previous to him "disconnected it" somehow. Wtf? He didn't know much mechanically so it was pointless to try to get more information from him. After trailering it home, I wanted to test it. I go to turn the hubs (which manual says should only ever be turned by fingers) and see what look like plier marks on the hubs. Trying to turn the hubs with my fingers revealed why there are plier marks, it just wouldn't budge. The 2wd seems to work all right, btw.

Can anyone offer some steps to take to determine just what is meant by "disconnected" and how to find out what is wrong (I'm assuming a transfer case or hub issue) in a logical manner? I have basic tools and basic skills, never did any work on an axle or tc before, except changing fluid, but there's one way to fix that, right? I want/need to do all I can on this project truck myself for $$$ reasons, but there are cases where it's cheaper to bring in an expert. Recommendations?

If you are new to the world of "old skool" 4x4 stuff, I really think the best $$$ you can invest now is in a service manual for that rig! I don't always feel that way, but in this case I do.

IH used several different "locking front hubs" on the Scout II and they are not "all the same" in design and maintenance points, they they do all interchange when replaced as a complete unit.

If you determine that the locking hubs are problematic, I think the best solution is to ditch the pair you have now and install a pair of new ones from one of many vendors that are readily available. The oem hubs can eat your lunch in trying to poorboy 'em into correct operation, I really feel they were somewhat marginal in load capacity/quality as compared to the aftermarket versions from the same supplier to ihc. And 30+ years of no maintenance on locking hubs renders them useless.

Even if the locking hubs on the front are totally trashed, ya still need to start at the beginning and verify the front and rear drivelines are functional. Do this with all four wheels off the ground and the rig up on stands of some sort! Then actually engage the transfer case in 4 high and see what happens. If the front locking hubs are disengaged or trashed, the front driveshaft will spin along with the differential and axle shafts, but the wheels are disconnected and will not spin except possibly through parasitic drag. If the front driveshaft will not spin/engage, then ya gotta transfer case issue and teardown is called for.

Ya gotta figure out what is happening before ya can make a diagnosis as to what kind of repair will be needed in order to make the complete 4x4 system functional.

 

[bruss01]

if you are new to the world of "old skool" 4x4 stuff, I really think the best $$$ you can invest now is in a service manual for that rig! I don't always feel that way, but in this case I do.

Thanks for the replies. I once owned an 86 grand wagoneer (the old style) and did things like brakes and put a 3" lift under it. I already got the factory manual for the 78 Scout, it goes into quite a bit of detail and what I was looking for was more "big picture" stuff before getting down to the point where gears-n-stuff are coming out and lying all over... Wanted to see if there was a standard way of "disconnecting" the 4wd and I was just unfamiliar with how the term was being used.

Sounds like you are recommending I replace the locking hubs first off before going any further, since they won't turn by hand like the manual says only to ever turn them, and I can't engage the 4wd without first engaging the hubs (again, according to the manual) without damaging the tc... Will let you know when I get that far, will take lots of pics. Thanks.

Btw, love your sig lines (in red).

 

[Michael Mayben]

thanks for the replies. I once owned an 86 grand wagoneer (the old style) and did things like brakes and put a 3" lift under it. I already got the factory manual for the 78 Scout, it goes into quite a bit of detail and what I was looking for was more "big picture" stuff before getting down to the point where gears-n-stuff are coming out and lying all over... Wanted to see if there was a standard way of "disconnecting" the 4wd and I was just unfamiliar with how the term was being used.

Sounds like you are recommending I replace the locking hubs first off before going any further, since they won't turn by hand like the manual says only to ever turn them, and I can't engage the 4wd without first engaging the hubs (again, according to the manual) without damaging the tc... Will let you know when I get that far. Thanks.

Don't replace anything until you diagnose what is going on!

It's very common to have to use pliers or whatever to twist the hub control. Most especially if they have not been maintained. Some of the earliest locking hubs have a rawhide internal seal and those can really lead to inop hub controls due to invasion of water/mud/salt resulting in massive corrosion over time...but the same holds true for the hub controls with rubber seals.

When the locking hubs were new (and properly maintained), all that is required to lock/unlock is turning the control by hand.

And let's not confuse this by talking about the "auto-lock" variations of locking hubs. Those are a different spin on the manual locking hubs that have their own unique set of issues regarding breakage/maintenance.

We're assuming here that the hubs you have right now, are the units that were oem on the rig, not some aftermarket replacement hub from a manufacturer other than warn. That is important that we know exactly which locking hubs you are dealing with, pictures will tell the story.

If the hubs are not damaged component-wise, then they can be totally dismantled and cleaned/polished/lubricated and brought back to life with alotta benchwork. I do this quite often just for the challenge but then I have many that are nothing but parts donors for hubs that are either missing pieces or have damage, most folks don't have that luxury.

If you have the two volume Scout II manual, cts 2304, you can see how "complicated" this whole hub issue can be! That manual is a mish-mash of hub-related stuff that shows many variations that were available over time, some of the units shown in that manual were never available on the '77 and later sii axles and go all the way back to 1962 for the Scout 80 with a d27 closed knuckle steering axle...but the manual doesn't' allude to that so the confusion is rampant!

You "disconnect" the front axle by positioning the stick/sticks and placing the transfer case in either 2wd or neutral (disconnects rear driveshaft also).

So first ya need to determine if the transfer case will actually shift...and then what happens if it will shift!

 

[bruss01]

Ok, thanks again. Just one point of clarification... You say first see if it will shift. Should I understand you to mean use pliers/leverage/whatever-it-takes to engage the hubs and then try shifting the tc? Or do you mean ignore the hubs for now and try it as-is?

I'm a little leery of using pliers to turn the hubs, that could void the warranty don't 'cha know...

appreciate the advice.

 

[Michael Mayben]

Scruu the warranty! Use pliers, a hammer and punch, big tree limb, whatever to make that hub control move!

Hub controls with plier tooth-tracks mean they are experienced and well broken in!

Work with the transfer case stick first, shifting in and out of the various positions. With the rig up on stands, it doesn't need to be running to begin with. Put the trans in neutral and you can turn the driveshaft(s) by hand from underneath while someone else plays with the stick.

These transfer cases are very crude in design, and they can be difficult to shift in and out without some manipulation. They don't work as smoothly and precisely as say a manual four speed transmission which just clicks through the gears! Even when perfect, it sometimes to difficult to get 'em shifted out of 4l and back into 2h without the engine running and moving the tranny back and forth between d and r.

Another thing to do...with the front axle up in the air...shift the transfer case into 4l. Then work with one hub only trying to engage/disengage while rocking the wheel back and forth to "help" the hub locks move internally. You can easily feel when the front axle stub shaft engages and disengages. Then do the other side. It May in fact have only one locking hub operational (or broke!).

But scruuin' with the hubs themselves is not viable until you have verified if the transfer case will engage all the positions as the stick is moved around.

By the way...my personal preference regarding old skool/part-time 4x4 stuff, toss the locking hubs and run drive flanges (or as some call 'em ..."slugs" if the internal spline hub design) like the original axle design incorporated starting around 1935! The oem design d44 hub system used on the Scout II axle is a weak link in the locking hub department, IH could have used the internal spline hub system like was oem on the pickalls, but no...they went for "cost reduction" on the Scout II.

 

[MarkO]

As per usual, mm has hit all the important points.

I am going to chime in and repeat some of what mm said.

The first thing I would do is check to make sure you have all of the driveshafts in place and working.

I had a '74 3/4-ton that had the four wheel stop working due to spun splines on the front driveshaft--everything was operable except the front driveshaft spun on the splines on the front slip yoke.

The next thing I would check is verify the t-case actually shifts into four wheel. With the vehicle safely blocked up with the wheels off the ground it should be fairly easy to determine if the t-case is shifting between two wheel and four wheel.

If you determine you are getting power to the front axle it would be at this point I would look at the front hubs.

Front hubs are not that complex. If you can take pictures of each step of the disassembly/assembly and only do one at a time you shouldn't have any problem working on them. You will need to learn how to take them apart in order to service front wheel bearings and brakes so learning how now is just another step in learning how your Scout was put together.

If you have any questions don't hesitate about asking. The only dumb questions are the ones that aren't asked.

Good luck and welcome to the addiction.

Mark o.
Winlock, wa