Solved School Me (and you?!) On Viscous Couplings (BW4404)

[gavin]

replacement viscous-coupling's are too spendy.

I'm now positive the VC in mine is seized/seizing up. Since I cannot find a 4406 manual t-case anywhere for a decent price (only junkyard with 'em want $700), I'm looking into replacing the VC. Plus, I'm about to buy myself a place, so won't be able to afford the misc. parts for a manual t-case swap (yet).

Borg Warner OEM Part #4404-625-001
Can be found here: http://www.drivetrain.com/parts_catalog/transfer_case_replacements_and_parts/bw4404.html
for just under $200.

I called up a local driveline shop, Six States, and they can get it for about the same price, plus freight (unless I can wait 2 weeks for it to ride on their usual shipment).

 

[gavin]

yes... my VC is basically seized.

chirped my rear tires the other day, with no front driveshaft in!

and I gained 2mpg+ just by removing the front shaft.

yup... my VC is toast.

 

[pubenemy]

My understanding is the chain runs the rear output correct? Im thinking about rebuilding my awd tcase from a 97 mountaineer. I see rebuild kits without a chain, then a chain sold seperately. Trying to figure out what parts i need. The suv only ran in fwd, with the front driveshaft removed it didnt move. So Im thinking whatever runs the rear is what I need to replace. Also what fluid do I put in there after rebuild ATF?
Thanks

 

[gavin]

I see you already saw my thread on rebuilding the t-case.

the chain, essentially, runs both front and rear outputs. The viscous coupling is where the power is "separated"

with over 180k on mine, the chain is still in perfect condition, but my viscous coupling is shot, I'm pretty sure.

it sounds like your VC is shot. if you look at the pictures in my rebuild thread, you can see that the the chain runs from a gear on the input shaft, to the front output. That gear is not part of the viscous coupling. It's possible the VC is toast, and is "free-spooling" (fluid inside the VC is not thickening, so there is no friction inside the VC, preventing the 2 halves from moving as a whole). make sense?

a replacement VC is going to cost around $300-$400.
up here in Alaska we have a Six States Distributors, which is where I ordered mine from... should be in this week, and will tackle tearing apart my t-case for the 3rd time.

it may be cheaper to find a junkyard t-case unit. Up here in Alaska, that is not the case. All used cases I've found are going for $300+. Why buy a used t-case, with used VC, when it will cost just as much to replace my VC and make the case like-new again.

edit: and it uses Mercon ATF. How much? ummm... a bit less than 2 quarts I believe.

 

[pubenemy]

Man so 300-400 for just the viscous coupler? Then like another 100ish for the other rebuild parts 100ish for a chain. If you wanted to do a full rebuild and not just find the bad part. Thats getting close to being able to buy a new/reman'd one with warranty! Ouch...

I did buy a used case, put it in today, its working fine except the fact its got no speedo sensor hookup and my original did.. So know speedometer for now.

Was thinking about rebuilding mine in the mean time but at those prices damn I dunno.. I can now that the broke tcase is out turn each output shaft by hand in opposite directions pretty easily.

I got the used tcase and driveshaft $260 shipped. Now I didnt get exactly what I needed tho so now Im going in deeper... I just need cheap wheels to get to/from work this economy is killin me! =)

I went from driving a brand new $52k turbo diesel 4 door with almost all options, that the company paid the payment and gas on, to them laying me off due to no work, no longer making the payments and floridas measly unemployment pay of 275/week no way I could afford it, so it was taken. Picked up the Mountaineer for $600 135k miles, got around $1k into it now with the tcase/driveshaft/used tires/front bumper. So not too bad..

Thanks for the input.
-Mike

I see you already saw my thread on rebuilding the t-case.

the chain, essentially, runs both front and rear outputs. The viscous coupling is where the power is "separated"

with over 180k on mine, the chain is still in perfect condition, but my viscous coupling is shot, I'm pretty sure.

it sounds like your VC is shot. if you look at the pictures in my rebuild thread, you can see that the the chain runs from a gear on the input shaft, to the front output. That gear is not part of the viscous coupling. It's possible the VC is toast, and is "free-spooling" (fluid inside the VC is not thickening, so there is no friction inside the VC, preventing the 2 halves from moving as a whole). make sense?

a replacement VC is going to cost around $300-$400.
up here in Alaska we have a Six States Distributors, which is where I ordered mine from... should be in this week, and will tackle tearing apart my t-case for the 3rd time.

it may be cheaper to find a junkyard t-case unit. Up here in Alaska, that is not the case. All used cases I've found are going for $300+. Why buy a used t-case, with used VC, when it will cost just as much to replace my VC and make the case like-new again.

edit: and it uses Mercon ATF. How much? ummm... a bit less than 2 quarts I believe.

Oh and I dont know if the one was drained before it was shipped the one I put in but I undid the top square bolt with the back end jacked up and only got like half a quart in before it was coming back out on me. How do you check it? Just undo the top bolt and make sure theres fluid at least to that level?
Thanks again

 

[gavin]

most likely the chain would not be necessary. As I mentioned on mine, my chain is still in great condition at >170k miles.
a bearing and seal kit will run around $100.
and yes, around $300 for the VC.
Not always worth it, depending on what you can find locally. There just isn't anything up here in AK. Closest one for me is $650 for one with 71k miles from a junkyard. No thanks, rebuilding it is cheaper (for me).

and yes, to check the level you would just pull the fill plug and check (which would be the same way to check a differential).

 

[pubenemy]

They really dont make it easy to fill I mean not much room even jacking it up then to get fluid in there at that angle? Never had to check or replace diff fluid before. There was two plugs one low down one higher up so I figured welp I fill as much as I can up to this top one. Made a mess of things too btw lol. OH and I forgot you had to get that plate off to get to some bolts and I was in a hurry so razor blade went through the carpet instead of taking it up properly :/

 

[gijoecam]

The chain drives the front output, but also provides *some* resistance to put the torque to the rear output. Otherwise, the VC is forced to slip (assuming it's operating properly) while driving the rear.

But the chain itself is connected to the front output.

 

[mountaineer02]

yes... my VC is basically seized.

chirped my rear tires the other day, with no front driveshaft in!

and I gained 2mpg+ just by removing the front shaft.

yup... my VC is toast.

I dropped my front driveshaft and still have the prob after I run it for awhile. Is it safe to say its NOT the viscous coupling?

 

[gavin]

I dropped my front driveshaft and still have the prob after I run it for awhile. Is it safe to say its NOT the viscous coupling?

what's the issue to begin with??

 

[mountaineer02]

After driving some distance, the vehicle will start to vibrate or shutter at speed lower then 15 mph when turning.

 

[gavin]

if it's only when turning, and issue persists without front driveshaft installed, highly doubtful it's the viscous coupling.

 

[mountaineer02]

Thats what i was thinking due to the threads ive read. Now to figure out WHAT it is?

 

[gavin]

my guess would be wheel hub/bearing assy

 

[mountaineer02]

On another thread somebody mentioned the diff clutch pak, do to the fact its limited slip and the way it gets worse as it warms up.

 

[gavin]

On another thread somebody mentioned the diff clutch pak, do to the fact its limited slip and the way it gets worse as it warms up.

certainly a possibility too.

 

[Joe Dirt]

gavin, when your VC was toast, did you get a clicking noise when rolling very slow like something was binding in the transfer case? We're still trying to diagnose my buddy's noise in his Ex, and it seems to bind a bit when turning, and there is a very noticeable clicking noise coming from the transfer case. We lifted the truck, all 4 off the ground. Start up, put in drive, and let off the brake slowly. When the wheels were just starting to roll, there was a loud clicking noise from the transfer case. When he lifted his foot off the brake entirely, and the wheels sped up, the noise was not there.

We're trying to find a replacement transfer case locally, but could it be the VC? Or should we be looking at a u-joint? With a stethescope, it's definitely making noise from the transfer case. But, we can't try the u-joint since it's spinning.

Any thoughts? gavin? gi? anyone? I figured that I'd keep it in this thread since he has the 4404...

 

[gavin]

cv-joint at t-case end of front driveshaft?
I never had any sort of clicking.

and most likely, if it was still clicking with all the wheels off the ground, chances are it's not the t-case binding up since it can't bind up when no tire has any friction.

and to be quite honest, I'm not even sure my old VC is bad.
My truck still has issues, so I don't think it ever was the VC.

 

[Joe Dirt]

Would there be enough binding when the brakes are partially applied? When it was in the air, and the brakes were partially applied, it was "popping" like a bad CV axle/joint would. When his foot was off the brake and the idle speed would turn the wheels totally, there was no noise. Same when starting to move when on the ground- 1-5mph there was popping, from then on nothing.

Ive read a lot of threads with the same symptoms of low speed popping and slight binding when turning being transfer case issues. Could it be the U-joints? The front CV axles and hubs are new. I was under the truck and it was definitely coming from either the rear of the transfer case or the U-joint attached to it and the rear driveshaft. I don't see how the U-joints would make noise only on low speed, and not that noise anyway...

Thoughts?

 

[gavin]

well, the only "clicking" I could see coming from the transfer case would be a bearing or the chain somehow causing the noise.

When the cv-joint went bad at the t-case end of my first front driveshaft, I did have similar symptoms. At first it was only noticeable at slower speeds. At higher speeds, the noise and whatnot went away. Of course over time it became worse, and just so happend to get totally shot on my way back home from a 40 mile (one-way) drive. It was fun driving that ~40 miles at about 25mph on a 65mph highway.

With the brakes not fully applied, I don't think binding would be an issue, since the tires could (theoretically) still spin at different speeds. And with only the brakes applied, I don't think there would be enough force to cause binding.

Of course, I could be totally wrong.