How to: Rebuilding a Borg Warner 4404

[Kevin Barry]

Thanks for the advice. The liquid whatever it may be is thinner than grease and thicker than ATF, but could be mixed with some water I guess, kinds brownish in color. I was just concerned that there may be a seal behind there letting go. I've had my round of front and rear axle seal leaks recently and thought we might be springing another one. Does this CV/Shaft just bolt on? It looks fairly simple on the outside.

 

[gavin]

Thanks for the advice. The liquid whatever it may be is thinner than grease and thicker than ATF, but could be mixed with some water I guess, kinds brownish in color. I was just concerned that there may be a seal behind there letting go. I've had my round of front and rear axle seal leaks recently and thought we might be springing another one. Does this CV/Shaft just bolt on? It looks fairly simple on the outside.

yeah, if it's a browish color it's most likely grease. Although I have no clue what kind of grease is in the CV's; it's possible it's a thinner grease, but I really don't know.

And I can't say I've heard of a front output seal going out on this t-case.

There's 6 bolts and 3 weight spreaders(?) that bolt the shaft to the t-case.
iirc, they are a 5/16" head.

 

[Kevin Barry]

Gavin- Thanks again. Looks like this will be an upcoming project.

 

[Glacier991]

Very nice write up, and with the pictures I think very helpful. You get Glacier's TWO THUMBS UP !

 

[SoNic67]

Wrong post.

 

[blakshukvw]

The noises people usually associate with the TC being the cause are popping noises. My truck occasionally has a shudder when turning at low speeds that resonates through the truck so I can't pinpoint where it's coming from. I've yet to hear any popping.

Also, on a lift, when I turn the rear wheels by hand, all of the wheels turn, but occasionally there is heavy drag on the wheel I'm turning and then the center driveshaft spins at a different rate as does the front wheels. This is usually when turning the wheel in reverse but not always. Does this point to a VC in the TC as failing possibly? I disconnected the rear driveshaft so to eliminate the TC completely and this drag is completely eliminated. That makes me think VC. What do you think?

 

[gavin]

tough to say; sounds like it could be the viscous coupling.
but, the drag could possibly be coming from the front diff. I think?
it's certainly possible that a drag caused by the front diff, could cause a binding that would allow the VC to start "slipping" which would cause the driveshafts to rotate at different speeds, when on a lift.
Granted, it's an open front diff, so theoretically if one side started to drag or bind, the other tire should then rotate instead.

 

[blakshukvw]

I dont think the front open diff could cause it though I could remove the front driveshaft and see wht happens. Right now it seems to have the heavy drag when moving the wheels in reverse. Earlier it was both directions. If I spin both front wheels forward, it turns the rears and everything turns easily. If I turn both front wheels in reverse the heavy drag is there pretty consistently. If the VC were locked up then the front and rear wheels would turn at the same speeds even when turning and that is what I think is causing the shudder. The TC has to control some slippage through the VC so when turning it's not like driving a full engaged 4wd.

 

[blakshukvw]

I think when I spin the rear wheel, I'm overcoming the slip of the lsd and thats when the wheels turns easier, and thats happening because the VC is locked up or nearly 100% locked up. Why would it be worse in reverse though.

 

[gavin]

well for one, you won't be able to apply enough torque, by hand, to get the VC to "slip" with all the tires off the ground.

now that I think about it, I don't think the issue is directly related to the VC.

there is always a ~35/65 split of power front to rear.
which would mean, with all the tires off the ground, spinning one end should always cause the other end to rotate.

when you say the driveshafts do rotate at different speeds, something is causing a bind allowing the VC to "slip"

the end opposite of the one you're rotating will always spin slower; since the "power source" is the end you're rotating by hand.

 

[Wolfrom64]

Rebuild and new chain in the 4404 in my 96 explorer a couple of weeks ago. this thread really helped a lot.
Thanks. after 500 miles no issues runs smooth and noise free. It all cost less then $200

 

[mutt5956]

I know it's been a while since this thread was started, but I'm wondering how much you remember about having your TC apart.

Brief description of my problem: The truck was running fine, then 1 morning my Daughter drove it. She went about a mile from home, turned around and started back. Suddenly all she has is a noise that sounds like hamburger being ground, in all gears. No movement at all, forward or reverse.

Fast forward: after diagnosing, I determined the TC had an issue. After pulling it out and getting it on a table, at first glance it looks and acts normal. Pulled the plugs, drained the fluid, and then noticed a little more fluid in it so I turned it up and held it over the drain pan. When I did this I heard a clunk. Back on the table, I look things over again until I finally grab the input shaft to turn the TC around. When I did this, the shaft shifted away from the case. Now I start wondering, when the shaft is pushed in, everything appears as it should, both output shafts turn, but pull it out and nothing turns, the shaft just turns and moves nothing.

So, my question is this. What holds the input shaft in place? Surely it's not normal for this shaft to pull out like this and disengage. I haven't had the truck very long, and I did notice some vibration, but I attributed it the fact that it has different tires all around. There is some play at the input shaft, but little play at either output shafts. I will check all that out again if I decide to break it down.

Thanks for any reply....

 

[gavin]

Nothing really "holds" the input shaft in place, except for the press-fit of a bearing and the viscous coupling.

 

[Turdle]

I know it's been a while since this thread was started, but I'm wondering how much you remember about having your TC apart.

Brief description of my problem: The truck was running fine, then 1 morning my Daughter drove it. She went about a mile from home, turned around and started back. Suddenly all she has is a noise that sounds like hamburger being ground, in all gears. No movement at all, forward or reverse.

Fast forward: after diagnosing, I determined the TC had an issue. After pulling it out and getting it on a table, at first glance it looks and acts normal. Pulled the plugs, drained the fluid, and then noticed a little more fluid in it so I turned it up and held it over the drain pan. When I did this I heard a clunk. Back on the table, I look things over again until I finally grab the input shaft to turn the TC around. When I did this, the shaft shifted away from the case. Now I start wondering, when the shaft is pushed in, everything appears as it should, both output shafts turn, but pull it out and nothing turns, the shaft just turns and moves nothing.

So, my question is this. What holds the input shaft in place? Surely it's not normal for this shaft to pull out like this and disengage. I haven't had the truck very long, and I did notice some vibration, but I attributed it the fact that it has different tires all around. There is some play at the input shaft, but little play at either output shafts. I will check all that out again if I decide to break it down.

Thanks for any reply....

Did you drive it without the front drive shaft? How did it sound then?


Mismatched tires, even if the same "size" will not actually be the same diameter, and quickly damage the awd system

 

[mutt5956]

Guess that means the bearing, or input shaft are worn to the point that a press fit isn't doing it then. One or both will need replaced!

Trudle, yes it was driven without the front drive shaft. I bought it that way, the seller telling me that I could read it on the net that it would save me mileage and not hurt anything. After reading on it, I came to the conclusion that was wrong! Before I could reinstall it I came up with this problem. I only had it a matter of a couple of days at this point.

No I am not happy to have only owned this truck for days when it became a brick on the driveway, but it ran fine when I drove it the 50 miles home. Since it's a spare vehicle, and I am leaving on vacation the end of the week, I will be taking my time getting it running. Not like I don't have plenty to do around here, but paying for a fix is out of the question (who has that kind of spare cash?), especially when this is something I have the knowledge to do on my own. What can't be accomplished in my garage, will be taken to a friend's machine shop. He let's me use his shop free of charge whenever I have the need.

I have located the u-joint for the front shaft, but no bolts for the TC end. Anyone happen to know what they are? Bolt size, length, and grade? I want to make sure I get the right thing and if I can't get the info any other way, I'll pay a visit to a local Ford dealer for information.

Thanks for all the good information, the pictures helped me a little, but getting it open will do more for me.

 

[CDW6212R]

Guess that means the bearing, or input shaft are worn to the point that a press fit isn't doing it then. One or both will need replaced!

Trudle, yes it was driven without the front drive shaft. I bought it that way, the seller telling me that I could read it on the net that it would save me mileage and not hurt anything. After reading on it, I came to the conclusion that was wrong! Before I could reinstall it I came up with this problem. I only had it a matter of a couple of days at this point.

No I am not happy to have only owned this truck for days when it became a brick on the driveway, but it ran fine when I drove it the 50 miles home. Since it's a spare vehicle, and I am leaving on vacation the end of the week, I will be taking my time getting it running. Not like I don't have plenty to do around here, but paying for a fix is out of the question (who has that kind of spare cash?), especially when this is something I have the knowledge to do on my own. What can't be accomplished in my garage, will be taken to a friend's machine shop. He let's me use his shop free of charge whenever I have the need.

I have located the u-joint for the front shaft, but no bolts for the TC end. Anyone happen to know what they are? Bolt size, length, and grade? I want to make sure I get the right thing and if I can't get the info any other way, I'll pay a visit to a local Ford dealer for information.

Thanks for all the good information, the pictures helped me a little, but getting it open will do more for me.

The AWD 302's weak link is the front driveshaft, most have been replaced at some point. Early on there were no options but the OEM part, and expensive. Now you can get them rebuilt, or a new unit elsewhere.

The transfer case is reliable, until tires of different diameters are used. That kills the TC fast, so that is likely what you have. The last owner probably found out he could pull the front shaft and be cheap, with the odd tires until he wanted to sell it.

Fix the TC, and install four identical tires before putting a front shaft back in it.

BTW, I have a usable 97 AWD TC you may be able to use if money is tight. I bought a 97 trans and TC in 2005 from a truck(fire), for the trans as a spare. I haven't needed either yet, and I'm going away from the AWD soon. You'd have to have one with the VSS in the rear of it, 1998 stopped having that. I was told these have about 75k miles on them.

 

[mutt5956]

Ok, for those of you following along. I broke the TC open yesterday. Big surprise inside that I didn't expect to see after everything I have read on this. I found the bushing used to hold the input shaft was eaten up, and then beyond that into the case itself. So, basically I have a brick now! At least the front half is beyond repair. The rest looks to be alright other than all the metal fines that floated around in there for who knows how long. Still it appears to have little damage other than the bushing and case.

Lacking a tech manual on this, and the fact that replacing it in one piece appears cheaper and easier than replacing just the front half, I will opt to toss this one aside and replace the TC as a whole.

Don, I will send you a message about your post.

Thanks for all the help and information guys!

 

[torqlox]

Seeking to rebuild...

First of all I want to thank Gavin for such a great thread. I have quickly disarmed dealers and mechanics alike from touching my vehicles for the last 10 years thanks to the wealth of information attained in these forums. Well I picked up my white 2000 Mounty AWD this past June, and got everything refurbished on it. The previous owner had the front DS in a flower box sitting in the back, after telling me that his mechanic told him "taking it off if the best thing to do"

Well after rebuilding the drive shaft, I would get the infamous "klunk" when accelerating/decelerating/turning.

Apparently, the only thing remaining to be done, is to rebuild the T-case. Before I pull mine off, I want to make sure I have everything I need. In your original teardown report you stated that you wish you had all "the right tools". Can you make a quick checklist on what I should have on hand before I tear this baby apart? As far as parts, I am looking at the following:

Rebuild Kit (Bearings and bushings)
VC Unit
Chain

Thanks for your time!

 

[gavin]

As far as parts, I am looking at the following:

Rebuild Kit (Bearings and bushings)
VC Unit
Chain

Thanks for your time!

Looks right for parts.
Should have less issue finding the right part number for the chain; 97 had 2 part numbers listed, and the only difference was 1 link width.

As for tools; I think the only thing I didn't have, that would have been very beneficial, was a blind-hole puller. 1 of the bearings for the front output I managed to remove without it; the other was a very small one for the rear output.

Other than that, the bearing/seal installers were good to have.

The one clip holding the sun(?) gear to the output shaft was a PITA, but I'm not sure what would make it easier (due to it's depth in the case.)

 

[torqlox]

Sounds about right thank you. Going to make sure I have everything ready plus a good running second vehicle for work when I attempt this.