Transfer Case Clunking

[Diano Gabbana]

a 2004 has live hubs, they don't disengage-ever. the front diff is always turning with the wheels. the only front disconnect is inside the transfer case.

the transfer case has 2 separate shift mechanisms inside. one slides the range reduction from hi to low, in the process of that is a neutral spot that gets passed over.
that would put all 4 wheels in neutral if it got stuck there.
the other engages the chain/front driveshaft, at that point the rear driveshaft is always engaged to that mechanism.
if it slips the rear stays powered, the front loses power.

both mechanisms are powered by the same shaft via the shift motor. the shift forks are spring loaded so the motor rotating the shaft
only tells it to attempt to shift, the actual shifting happens when the gears align and the springs push the shift forks to engage.

that could possibly explain the front dropping out. if it doesn't engage fully and pops out the springs will attempt to push it back in.



check out this thread, download the manual.
the cases listed are earlier than yours, the front outputs are different, the internals are the same

Warner Gear 1350 -1354 Manual found | The Ranger Station

Wow Thankyou for the info, haven’t pulled my TC apart yet so this so very helpful, sounds like I could have a be having issues with the chain driven gear or fork like your sayin, I’ll look more into it!!

 

[Diano Gabbana]

Mine fully lock, and I think both are limited slip. In 4WD turning, just here in the yard it's digging it up just trying to turn, does the same on rocks and gravel

My truck has a rear 8.8 LSD and a front D35 - Sla which like pjtoledo said it’s just the open diff version of the real D35. I don’t have anything special just a regular open diff on the front

 

[Josh B]

I guess it isn't positively for certain, but when it's in 4WD the wheels all turn together at the same rate. A turn will have the inside tires turning the same distance as the outside wheels, leaving the outside to cause a bit of drag, and the inner ones digging things up a bit. I'd almost be afraid to engage it on a very hard surface

I wanted to do a turn around in the yard today if I had room to turn it there and see how it showed in a photo but got too busy and forgot it till now

 

[Josh B]

I also think there's some confusion about being locked in, and I am not certain who actually used it or how many times.
All I've tried to imply is that when in 4WD the front is as engaged as the rear, and as far as I know all four tires turn equally, even through a turn.

 

[James Morse]

Thanks Josh I understand what you're saying. It does sound like things are locked up (side to side), which seems different than how I understand it, but here's the thing, there are a bunch of people on here who know a lot more about it so hopefully one of them will chime in and tell us, on your '93 (and my '97, which should be same gen), are the diff's locked or not? (I think not) With my limited experience, I think mine acts the same way (as if they are locked side-to-side) so something is a little weird in how I'm understanding it.

If the only "locking" is front to rear (per side) I suppose it could still cause the same thing? In other words if the fronts are trying to turn at a different rate from the backs, then it could cause it, even if they weren't locked side-to-side.

Edit: started General Discussion thread about this

 

[Josh B]

I'm not really talking "locked", and I don't recall ever doing so, even if so I didn't mean it in the way yall seem to think.
When I engage 4WD all 4 wheels turn, at all times. Even in a turn they all pull, none of them slip or freewheel, they all stay engaged.
In a turn the wheels on the outside, I'll go on out now and see if it will show in the yard and I'll get you a photo that may explain more clearly

 

[Josh B]

This is a left turn, the left wheel drags. IF it were a right turn the right wheel would do the same.
This only happens when turning and is specifically due to both axles being equally engaged

 

[rumblecloud]

Well...I don't know about anyone else, but I get it -- and I'm not that smart.

 

[dvdswan]

Welcome to the site. You will get this clunk when going through a belt driven car wash went entering and exiting the belt. One set of tires will be stopped while on the belt and the other set of tires will be turning because of the ground. The t/case is just reliving the stress between the moving and not moving axles.

 

[James Morse]

I get it. It's not locked up, it's binding.

 

[00t444e]

How does that fit in the scheme of Limited slip, locking, and (the axle where one side is always slipping)?

What is that kind of axle called?

The transfer case works the same no matter what type of differentials you have in the axles (open, limited slip or locked). In 2wd only the rear output gets power, in 4x4 high the front and rear outputs both get power and are locked together to turn at the same speed, in 4x4 low it is the same as 4x4 high only the output shafts turn 2.48 times slower than the input shaft since the BW1354 has a 2.48:1 low range gear.

 

[James Morse]

when you say "locked together" what you mean is the driveshafts are locked... but the front/rear wheels aren't locked, they bind by nature of the fact the differential ring/pinion have to turn the same speed and if you turn the truck there is no combination of differential action that can accomodate the different rotation speeds of all the 4 tires. Normally in the turn the front tire will end up sliding on the gravel and I don't know why this is, because you'd think the back, being lighter, would slide. Fact is, something has to give somewhere and that's where you see it. Probably just due to the geometry of things. A scale model would be enlightening.

left/right aren't locked at all when looking at just front or just rear. rears will be locked (to each other) only to the extent the lsd allows it. front is an open differential so it's never locked, of itself.

a thought experiment is, what if both front and rear have open differentials, would that still act the same? is the lsd somehow contributing to the binding, or no?

 

[00t444e]

Yes it would do the same thing if you had open differentials in both axles.

 

[James Morse]

This tells me that no matter what the differential is doing, power is being applied to at least one wheel front and back and they will be the same side (I think?) and therefore if they are not turning at the same rate due to the front wheels being turned left/right, there is a discrepancy between them and so you get the binding. And the front will slip/drag even though it's heavier because... well I lost it there, but we know how it behaves.

This is where a model would help me... but I think I'm starting to get it.

Either diff in and of itself has no problem negotiating turns without tires slipping/dragging. (no binding). But when front/rear are in sync because the driveshaft, ring, pinion, these all are turning at the same rate, seems to me that let's say you turn right, both diff's will be putting more power to the outside wheels (the left wheels), allowing the insides (the right) to turn slower (what diff's do). So it seems to me that if you have made the turn and are, say, driving in a pefect circle, then the front and rear inside and f/r outside tires are travelling exactly the same distance so it seems like there should be zero wheel drag/slip. Is this correct?

Maybe it is only when you -start- the turn that the problem happens? Because then the fronts are moving sideways (turning) but the backs are still going essentially straight.
I suppose some experimentation on a gravel surface would answer this... but from a how-it-works standpoint, am I at all on track?

 

[00t444e]

This tells me that no matter what the differential is doing, power is being applied to at least one wheel front and back and they will be the same side (I think?) and therefore if they are not turning at the same rate due to the front wheels being turned left/right, there is a discrepancy between them and so you get the binding. And the front will slip/drag even though it's heavier because... well I lost it there, but we know how it behaves.

This is where a model would help me... but I think I'm starting to get it.

Either diff in and of itself has no problem negotiating turns without tires slipping/dragging. (no binding). But when front/rear are in sync because the driveshaft, ring, pinion, these all are turning at the same rate, seems to me that let's say you turn right, both diff's will be putting more power to the outside wheels (the left wheels), allowing the insides (the right) to turn slower (what diff's do). So it seems to me that if you have made the turn and are, say, driving in a pefect circle, then the front and rear inside and f/r outside tires are travelling exactly the same distance so it seems like there should be zero wheel drag/slip. Is this correct?

Maybe it is only when you -start- the turn that the problem happens? Because then the fronts are moving sideways (turning) but the backs are still going essentially straight.
I suppose some experimentation on a gravel surface would answer this... but from a how-it-works standpoint, am I at all on track?

An open differential due to the way spider gears work always sends equal torque to both wheels and also allows them to spin at different speeds. You get binding in 4wd because there is no differential in the transfer case, and in a turn the front and rear axles travel different distances.