How to: Rebuilding a Borg Warner 4404

[Mbrooks420]

Wow, nice write up. Very interesting. Too bad it had to come out a second time. My rear output has more play than it should, thats prob where most of my vibrations come from. Prob also why my t case shakes itself loose once every year or two.

 

[Fordified1]

ohhhh you just bought a whole new(used) case. gotcha.
yeah, they are spendy. All the junkyards up here want $700+ for the 4404, regardless of miles.
which is why I ended up rebuilding it myself, saving ~$300 and having all new parts and writing this thread :

Is yours fixed now? I don't see a post past the driveway.

Mine needs a $350.00 viscous coupler (plus all the normal rebuild parts). The quick cheap fix was to buy a used case to get me by until I have time and funds to properly rebuild the old unit.

From what I have read (not just here). These 4404's are frequently mis-diagnosed as needing a new chain and sprockets.

 

[gavin]

Wow, nice write up. Very interesting. Too bad it had to come out a second time. My rear output has more play than it should, thats prob where most of my vibrations come from. Prob also why my t case shakes itself loose once every year or two.

actually it came out a 3rd time, too. After rebuilding, then tearing apart to replace a bearing and clean it after a failed bearing (due to bad install), I tore it apart again earlier this summer to replace the VC and replaced bearings again (destroyed bearing = lots and lots and lots of metal shavings, even after the first cleaning, there was still a LOT of shavings I got out the last time).
the rear output will have some play. But it's hard to say how much is too much, really. Although if it's "shaking itself loose," then there's definitely something wrong. Although not necessarily with the t-case.

Is yours fixed now? I don't see a post past the driveway.

Mine needs a $350.00 viscous coupler (plus all the normal rebuild parts). The quick cheap fix was to buy a used case to get me by until I have time and funds to properly rebuild the old unit.

From what I have read (not just here). These 4404's are frequently mis-diagnosed as needing a new chain and sprockets.

I highly doubt my t-case is the cause of issues I'm still having. My truck does still have issues, but I'm not 100% sure as to the cause. But as of this point, the only thing not replaced in the t-case is the chain, and it was still good. Plus the one I got was the wrong one anyway (2 different chains, 2 dif part #'s, but #teeth, pitch, and width was exactly the same; although one chain is actually 1 link wider than the other).
I highly doubt my t-case is still causing issues, as it seems to perform flawlessly. Have had absolutely no issues this winter driving in the snow and ice.

 

[Fordified1]

actually it came out a 3rd time, too. After rebuilding, then tearing apart to replace a bearing and clean it after a failed bearing (due to bad install), I tore it apart again earlier this summer to replace the VC and replaced bearings again (destroyed bearing = lots and lots and lots of metal shavings, even after the first cleaning, there was still a LOT of shavings I got out the last time).

I highly doubt my t-case is the cause of issues I'm still having. My truck does still have issues, but I'm not 100% sure as to the cause. But as of this point, the only thing not replaced in the t-case is the chain, and it was still good. Plus the one I got was the wrong one anyway (2 different chains, 2 dif part #'s, but #teeth, pitch, and width was exactly the same; although one chain is actually 1 link wider than the other).
I highly doubt my t-case is still causing issues, as it seems to perform flawlessly. Have had absolutely no issues this winter driving in the snow and ice.

Sooooo you saved money how?

I applaud you for diving in and trying to do the job yourself, but so far you have not saved yourself a dime.

I'm not trying to bust your balls or anything, I'm just hoping others reading this and contemplating "saving themselves some money" will at least use a proper rebuild manual. Not just an exploded view, but an assembly manual with torque values and bearing pre-load settings.

Sorry, but this thread has turned into a how NOT to rebuild a transfer case.

Your bearing failures are assembly related.

All good info none the less.


.

 

[gavin]

Sooooo you saved money how?

I applaud you for diving in and trying to do the job yourself, but so far you have not saved yourself a dime.

I'm not trying to bust your balls or anything, I'm just hoping others reading this and contemplating "saving themselves some money" will at least use a proper rebuild manual. Not just an exploded view, but an assembly manual with torque values and bearing pre-load settings.

Sorry, but this thread has turned into a how NOT to rebuild a transfer case.

Your bearing failures are assembly related.

All good info none the less.


.

used t-case = $700+
brand new t-case = >$1000

parts <$500

I screwed up on my first try. This is noted.
How is this a thread on how not to rebuild a t-case?
I screwed up, fixed it, and made sure to note the mistake I made.

pre-load values? torque values?
did you not notice there are absolultely NO bolts except the ones that hold the case halves together?
bearing pre-load? notice how there's NO way to adjust this?

what do you need a book for? if you have the balls to open the case and tear it apart, it's a cinch.
no need for a book.

and I also spent $200+ less, for NEW parts, than it would have costed me for a USED t-case in unknown shape.

So I essentially spent $200 less for a new t-case than a used one would have costed.

How is this not saving money?

 

[Fordified1]

used t-case = $700+
brand new t-case = >$1000

parts <$500

I screwed up on my first try. This is noted.
How is this a thread on how not to rebuild a t-case?
I screwed up, fixed it, and made sure to note the mistake I made.

pre-load values? torque values?
did you not notice there are absolultely NO bolts except the ones that hold the case halves together?
bearing pre-load? notice how there's NO way to adjust this?

what do you need a book for? if you have the balls to open the case and tear it apart, it's a cinch.
no need for a book.

How is this not saving money?

If you had used a book you might not have needed to replace the bearings twice, and the jury is still out on if it is really fixed yet. I'm betting more bearing failures are in your future.

Just looking at the way the yolk butts against that bearing race suggests that it needs to be pre-loaded against said bearing (with that "big nut" you had so much trouble with) and the pre-load checked with an inch lbs torque wrench like a differential housing does.

Any body who doesn't know what a planetary housing is "big gear" and has trouble getting a simple snap-ring off and on has no business doing a "how-to".

How NOT to fits much better.

 

[gavin]

If you had used a book you might not have needed to replace the bearings twice, and the jury is still out on if it is really fixed yet. I'm betting more bearing failures are in your future.

Just looking at the way the yolk butts against that bearing race suggests that it needs to be pre-loaded against said bearing (with that "big nut" you had so much trouble with) and the pre-load checked with an inch lbs torque wrench like a differential housing does.

Any body who doesn't know what a planetary housing is "big gear" and has trouble getting a simple snap-ring off and on has no business doing a "how-to".

How NOT to fits much better.

wait... now you're telling me I don't know what I'm doing?
why are you being some a... ok, I'll leave those words out.

No, I did not know the technical terms. Do you know the technical term to every single thing in the universe? I doubt not. Just because I don't know the technical names does NOT mean I don't know what I'm doing.

And the nut on the flange, well duh, because it's loc-tited on. Of course it's not easy to remove.
And actually, I did torque that nut down per torque specs in my Chilton's.

No, a book would not have helped. I just didn't pay enough attention when removing/reinstalling parts.

I learned from my mistakes, fixed it, and moved on.

Now quit being such a nagging nancy, and get out of this thread if you don't agree with the information I have provided. Go write your own if you think you're so much better.

 

[Mbrooks420]

Damn, I found this very informative, and would consider doing some t case rebuilding myself now. If you don't agree with what you read, just then don't use the info.

As for the t case shaking itself loose, the bolts have came loose on it twice. I also had the OEM front shaft fail, as well as a junk reman fail. Those both caused vibrations, which prob didn't help anything.

 

[gavin]

Damn, I found this very informative, and would consider doing some t case rebuilding myself now. If you don't agree with what you read, just then don't use the info.

As for the t case shaking itself loose, the bolts have came loose on it twice. I also had the OEM front shaft fail, as well as a junk reman fail. Those both caused vibrations, which prob didn't help anything.

Just pay more attention to it the first time, unlike I did, and it's easy as pie.

The CV shafts are known to be failure prone. I went through.... 4 I think? the original that was in it when I bought the truck, 2 junkyard units which lasted ~1yr each, then I finally got a new Ford OEM unit from ericautopart which has been working fine for.... a couple years I think? Can't remember when I got it.

I will say that the job would have been easier with a blind-hole puller to get a couple of the bearings out.

 

[Fordified1]

You are right. Sorry for being such an ass.

Just suggesting to anyone who wants to do this. Do yourself a favor, buy the service manual and do it right the first time. Plus the book will help you with little dis-assembly and assembly tricks that can drive you crazy. Special tools also.

Good luck to you.

.

 

[gavin]

FWIW, the torque spec for the rear output flange nut is 249-274 lb/ft.

and the AllData instructions on replacing the rear seal, which requires removing the flange, notes nothing about any kind of bearing pre-load.
just to tighten the nut to 249-274 lb/ft.

 

[Mbrooks420]

Wow, thats TIGHT.

 

[SmoothJimmy]

just curious Gavin, after the first problem-rebuild, you mentioned that the fore-aft play in the front shaft of the TC was almost gone when compared to pre-rebuild. After your subsequent rebuilds, is this still the case?

 

[gavin]

Wow, thats TIGHT.

and I don't think I even got it quite THAT tight... at the time, all I had was a 1/2" drive torque wrench that went to 250 lb/ft.
but I couldn't get enough leverage to hit 250.

I should double-check it one of these days.... since I now have a big ass 3/4" drive torque wrench that will hit 300 lb/ft (as long as the wrench isn't too long, since it is much larger than my 1/2" drive)

just curious Gavin, after the first problem-rebuild, you mentioned that the fore-aft play in the front shaft of the TC was almost gone when compared to pre-rebuild. After your subsequent rebuilds, is this still the case?

good question!

in all honesty; I see what I wrote... but I really don't see how the amount of fore-aft play can change.
the front-most bearing has a seat. A cir-clip goes on the front output shaft.
There's really no way for any of those to change.

I said there was a change; but it could have been one of those things where I thought there was a change, even if there wasn't. You know, kind of like the "seat-of-the-pants" feel when somebody upgrades something on their ride.

 

[SmoothJimmy]

like when ya wash the rig and it feels like the engine runs smoother?

in the medical world... a Placebo.

 

[gavin]

like when ya wash the rig and it feels like the engine runs smoother?

in the medical world... a Placebo.

that's the word I couldn't think of

 

[zekex2]

Hi Guys

Nice post up. Wish I had had this when I did my case the first time.

Just some things I have noted:

The rear nut torque setting is no bull. You want that tight. If it isn't, there will be some self destruction. The other thing is that the chains do stretch with age. Put a new chain up against the old on and you may see that there is a good 1/2" difference in length. I didn't swap that out on my first rebuild but did on the second. When I did the first round I had a lot of noise from the case still. When I took it back apart again I discovered wear on the main rear out put bushing that was caused by not getting the rear nut torqued properly the first time around.

So far the transfer case is doing it's job for the last six months with out problem. I have read that it is best to use full synthetic fluid in it instead of the normal fluid that I put in.

Now if I can just get it to stop eating hubs I will be kinda happy.

 

[Kevin Barry]

I know these posts are a few months old but am hoping you guys see this and can help. I noticed some drops of what appeared to be oil under the center of my 97 5.0 AWD this morning, took a look and it is leaking at the CV boot that mates to the TC. It looks like some type of mounting plate where the shaft goes through the center with the boot. Is there a seal up there as I see tons of posts of people removing the driveshaft with no mention of potential leaks? Or, is this grease from inside the boot? Smells like grease rather than ATF. I would say it is somewhat thick and brownish in color. I don't want to run the T-case dry but am curious what might be involved to rectify the leak? Thanks in advance.

 

[my pos mounty]

probably just the CV end of the front driveshaft dying on you

 

[gavin]

I know these posts are a few months old but am hoping you guys see this and can help. I noticed some drops of what appeared to be oil under the center of my 97 5.0 AWD this morning, took a look and it is leaking at the CV boot that mates to the TC. It looks like some type of mounting plate where the shaft goes through the center with the boot. Is there a seal up there as I see tons of posts of people removing the driveshaft with no mention of potential leaks? Or, is this grease from inside the boot? Smells like grease rather than ATF. I would say it is somewhat thick and brownish in color. I don't want to run the T-case dry but am curious what might be involved to rectify the leak? Thanks in advance.

carefully check the boot for rips and/or tears.
sounds like grease getting flung out of the cv cup.
Look into getting the shaft replaced.
ericautopart (vendor here) has great prices for replacements.

It doesn't sound like it needs immediate attention, but you may not want to wait too long if the boot does, in fact, have any rips or tears.