How to: Rebuilding a Borg Warner 4404

[masospaghetti]

I had a "clunk" on acceleration with no other symptoms, no binding while turning. I now have the case apart on my workbench.

The chain looks loose, how do I know when it needs to be replaced? Also, I have some play fore-aft in the front output flange, should this be tight? The case has 150,000 miles on it.

 

[gavin]

A clunk could be a u-joint or cv-joint on the front driveshaft.
Unfortunately, as I haven't seen or been abel to find any OEM documentation on the unit, I don't know how much play would still be within specs.

Some for-aft play in the front output flange wouldn't be unusual, as the front shaft is held in by a circlip. This obviously can't be tight or it would wear out the circlip.

 

[masospaghetti]

I am still looking for a real "overhaul" instruction for this thing, I feel like there has to be wear limits on these parts.

some questions I had though (BTW, great write up, its been very helpful):

- What kind of pliers did you use to spread that big retaining clip on the output shaft?
- Which way do the chain drive gears go? The gears aren't symmetrical. Do you have a picture of them assembled?
- The workshop manual specifically states NOT to remove the pilot bearing, although rebuild kits include a new one. I rented a "pilot bearing puller" from the store and I think it would make short work of it. Any reason that you know of, not to pull it out?

Thanks again!

 

[gavin]

- What kind of pliers did you use to spread that big retaining clip on the output shaft?

I don't think I used pliers. Just a couple long screwdrivers.
Yeah, getting it back on was a PITA. The clip doesn't have holes for any kind of actual circlip pliers. You would need a couple enormously long and small needle nose to make it easy.

- Which way do the chain drive gears go? The gears aren't symmetrical. Do you have a picture of them assembled?

I made sure to put them back on in the same order and orientation as I removed them. I guess I didn't pay enough attention to see that they were not symmetrical.

- The workshop manual specifically states NOT to remove the pilot bearing, although rebuild kits include a new one. I rented a "pilot bearing puller" from the store and I think it would make short work of it. Any reason that you know of, not to pull it out?

Is this the super tiny one that requires a blind hole puller?
If so, I don't see any reason not to replace it, assuming you have the proper tools (unlike myself, which mangled the *!$% out of it)

Ok so I just googled "pilot bearing puller" and I'm guessing my assumption was correct. I don't see any reason not to as long as the tool fits and works properly to remove the bearing.

Thanks again!

It wasn't a problem at all!

 

[masospaghetti]

Thanks for the reply. Wish me luck, I just ordered a new chain and rebuild kit from American powertrain warehouse.

Strangely, they show that the HV-051 chain to be correct for early build cases (96-97), so hopefully that's the correct chain. They had a great price on parts, $143 out the door for the kit (with Koyo bearings) and chain.

 

[gavin]

Thanks for the reply. Wish me luck, I just ordered a new chain and rebuild kit from American powertrain warehouse.

Strangely, they show that the HV-051 chain to be correct for early build cases (96-97), so hopefully that's the correct chain. They had a great price on parts, $143 out the door for the kit (with Koyo bearings) and chain.

FWIW, the only difference between the 2 is 1 link in width.
Here's my email to Anaheim Gear and their response, regarding the interchange between HV-051 and HV-070

From: Jeremy <@gmail.com> Mon, Oct 10, 2011 at 8:13 AM

To: pat@anaheimgear.com


In searching for a new chain for my BW 4404 t-case, I came across an eBay auction you folks have for a HV-070.
In the description, it says it will interchange with the HV-051.
I'm at work right now so I can't access eBay.

My question is, where did you get the interchange info? I purchased an HV-051 quite some time back, but found that it's actually 1-link skinnier than the chain currently in the transfer case.

I know the actual listed specs for both the HV-051 and HV-070 are exactly the same

I'm about to rebuild the transfer case again and would like to replace the chain; but if I can use the HV-051 I already have, I'd rather do that.

Your ad is the first place I've seen that says the 2 part numbers are interchangable, and I'm just curious where you got that info since I haven't been able to find that myself.


Thanks,
Jeremy

From: Pat <pat@anaheimgear.com> Mon, Oct 10, 2011 at 10:20 AM

To: Jeremy <@gmail.com>

Jeremy,

We have been only using the 070 chain for several years. I do not know what the difference is between the two numbers, but they have the same dimensions, width, number of links and call for the same sprockets.

Pat

From: Jeremy <@gmail.com> Mon, Oct 10, 2011 at 2:03 PM

To: Pat <pat@anaheimgear.com>


Thanks Pat!

When I counted mine, the HV-051 was 9 & 10 links wide, whereas the original chain was 10 & 11 links wide, I believe it was.

I'm wondering if they changed the chain with one of the iterations of the t-case, since it's had at least 3 iterations; the change frrom the flat front output flange to the "cup," then the removal of the speed sensor from the tailshaft.

I used the HV-070 myself. Although I think I may have found the HV-051, which is how I determined the (minimal) width difference.

 

[masospaghetti]

So the overall width is the same, but the HV-051 has wider links (since it has 1 less link)?

 

[gavin]

So the overall width is the same, but the HV-051 has wider links (since it has 1 less link)?

I didn't measure myself, so I don't know if the actual measured width is slightly different.
It's possible, since the difference in width is so small, they're both labeled as 1.25" wide

 

[mtnlovrs]

I didn't measure myself, so I don't know if the actual measured width is slightly different.
It's possible, since the difference in width is so small, they're both labeled as 1.25" wide

Yes it is... I measured my chain at 1 5/16" (10&11 links wide). When I ordered my chain, exactly like yours Gavin, they told me the correct chain was the HV-051 because they only go by the one blue link. I have compared the chains and don't believe it is the correct chain because it looks completely different and seems to be looser and flimsier than the old chain with 228K miles on it. It does fit the gears; in fact it fits them tighter and is about 5/16" shorter in length with the gears applied inside the chain than the old one (because the old one is stretched). I took the chain to a local transmission shop and asked their guy, that does all of the transfer case rebuilds, what he thought and he said that he would use the 051 chain because of the one blue link, "That's what they go by" he said. I'm still dissatisfied with his answer and I am wondering if anyone has a HV-070 chain that they wouldn't mind taking pictures of and posting on this thread? Your supposed to check your chain by holding it sideways (the way it's not supposed to bend) and seeing how much it bows (banana shaped), but when I hold the new chain next to my old one, I can see that the new one bows a lot worse than the old one. Lastly, I'm wondering why two different chains? Well, the best answer I could surmise is the HV-051 fits both 4404 and 4405 transfer cases, which leads me to believe it is designed for the less torquier V6 engine and the HV-070 (with two blue links) fits only the 5.0 V8 4404 according to nearly every website I've been to. That's why I would like to compare these two chains side by side, for example, does one bow more than the other when held sideways? Still confused!

 

[mtnlovrs]

No one replied, so I went ahead and used the HV-051 on my brother-in-law's Explorer. He seems to be happy with it and has no problems to report. I'm still curious though what the difference is between those two chains. If anyone is able to compare the two, please post.
Thank you, Gavin, for starting this thread and all the great photos!!! You helped me out more than you know!

 

[1998rollover]

Just finished a rebuild on a BW4404. 070 Chain, bearings, bushings, seals, thrust washers and rebuilt VC from STE.

Also had to replace the input shaft because of wear on its thrust face and it was slightly bent. I chucked it in my old Monarch 12CK lathe to see if I could true up the thrust face then add a hardened thrust washer. Yes, would have worked except for the wobble from the bend.

Cobra Transmission has the best price on the 4404 input shaft, and now they actually have their inventory information on it correct, after they sent me a part that's not even in the 4404, and after saying they didn't have any of the input shafts in stock. I asked if they had a good used one, which is what they were supposed to have sent since they "didn't have" a new one.Turned out they had the correct new shaft in stock when I ordered it. The new shaft came with a new plastic oil scoop installed in the small end.

Only took about an hour on the phone to get that straightened out.

 

[mtnlovrs]

Just finished a rebuild on a BW4404. 070 Chain, bearings, bushings, seals, thrust washers and rebuilt VC from STE.

Also had to replace the input shaft because of wear on its thrust face and it was slightly bent. I chucked it in my old Monarch 12CK lathe to see if I could true up the thrust face then add a hardened thrust washer. Yes, would have worked except for the wobble from the bend.

Cobra Transmission has the best price on the 4404 input shaft, and now they actually have their inventory information on it correct, after they sent me a part that's not even in the 4404, and after saying they didn't have any of the input shafts in stock. I asked if they had a good used one, which is what they were supposed to have sent since they "didn't have" a new one.Turned out they had the correct new shaft in stock when I ordered it. The new shaft came with a new plastic oil scoop installed in the small end.

Only took about an hour on the phone to get that straightened out.

I also went with Cobra Transmission and had a similar experience. It's good to here they finally got their inventory information correct. Are they still recommending the 051 chain? I see that you went with the 070 chain... did it work well with this case?

 

[1998rollover]

I got the chain from somewhere else. I shopped around, eBay, Amazon, Cobra and more to get the best prices on every part. Got a rebuilt VC from STE, which is apparently the only place that rebuilds them.

The real crazy thing with Cobra is they had the wrong part inside a bag, inside another bag, with the right number for the BW4404 input shaft on both bags. Takes some effort to bag a part wrong twice.

Am now looking into doing a 302 into an 02 Sport Trac swap with the "old" 98 Mountaineer (which is actually newer than the "new" 98 - that was built in late 97) as the donor. I'll rebuild its BW4404 too as it's been replaced and is now getting towards the miles when the chain gets stretched and jumpy. I'll also transplant the mountie's axles to get the higher ratio for better MPG with the Trac's larger tires. I did the math and at 65 in overdrive that should have the 5.0 loafing along at 1,900 RPM or thereabout, with go-power just a foot wiggle away.

Should be a simpler job than the 1991 Chevy pickup drivetrain into a 1982 GMC 1-ton flatbed dually transplant I'm still working on... ;P

 

[CDW6212R]

I got the chain from somewhere else. I shopped around, eBay, Amazon, Cobra and more to get the best prices on every part. Got a rebuilt VC from STE, which is apparently the only place that rebuilds them.

The real crazy thing with Cobra is they had the wrong part inside a bag, inside another bag, with the right number for the BW4404 input shaft on both bags. Takes some effort to bag a part wrong twice.

Am now looking into doing a 302 into an 02 Sport Trac swap with the "old" 98 Mountaineer (which is actually newer than the "new" 98 - that was built in late 97) as the donor. I'll rebuild its BW4404 too as it's been replaced and is now getting towards the miles when the chain gets stretched and jumpy. I'll also transplant the mountie's axles to get the higher ratio for better MPG with the Trac's larger tires. I did the math and at 65 in overdrive that should have the 5.0 loafing along at 1,900 RPM or thereabout, with go-power just a foot wiggle away.

Should be a simpler job than the 1991 Chevy pickup drivetrain into a 1982 GMC 1-ton flatbed dually transplant I'm still working on... ;P

That sounds like a fun project, both of them really. Have you considered doing the BW4406 swap for the Sport Trac too? Making it actually 4WD is most people's preference.

I'm going to convert my 99 Explorer to a 302 also, and I'm not sure if I would need the 4WD versus AWD. I'll have to decide on that and choose to rebuild an AWD, or hunt another BB4406 etc.

 

[1998rollover]

The Trac is 4WD. I want AWD, and the rear disc brakes. I don't go off-roading, the AWD is just so fine on slick winter roads. Always there and ready anytime the rear wheels lose the least bit of traction.

 

[CDW6212R]

I've got the 4WD in my Explorer also, I'm not sure how the BW4406 will be much different, if any.

 

[daveyhouse]

I am still looking for a real "overhaul" instruction for this thing, I feel like there has to be wear limits on these parts.

some questions I had though (BTW, great write up, its been very helpful):

- What kind of pliers did you use to spread that big retaining clip on the output shaft?
- Which way do the chain drive gears go? The gears aren't symmetrical. Do you have a picture of them assembled?
- The workshop manual specifically states NOT to remove the pilot bearing, although rebuild kits include a new one. I rented a "pilot bearing puller" from the store and I think it would make short work of it. Any reason that you know of, not to pull it out?

Thanks again!

I realize you asked this over a year ago, but it might help someone else.
I used a long pair needle nose pliers I got from Harbor freight with about a 45* bend on the tip to open it.


Once it was out, I used a file to put some notches in it so could use locking circlip pliers which I also purchased from HF. It made installation a breeze.

 

[daveyhouse]

I also purchased my kit from american powertrain warehouse. There is one bearing in the kit that had a circlip installed on it. After at least a half dozen failed attempts at mating the two half cases together I realized I had to remove this circlip. Once removed my dilemma was also gone.

They offer two kits for the 4404. One with speedo in the TC and one without. My case had no speedo. My speedo is in the transmission which I also just rebuilt myself and installed a shift kit (4RW70), but I did not take many pics sorry. It was definitely a learning experience.

 

[daveyhouse]

I used 3 legged puller to remove this bearing, but in order to do so I had to grind the heels of the legs down. If you look closely you can see the flat spots on the bottom of them.

I was unable to get anything I had under this bearing so I took half of bearing separator and hit it with hammer while rotating it until I got it out far enough to get the separator under it.

I used a piece of pvc pipe and hammer to put new bearing on. (Ghetto Style)Using the inner race.
Note only press the side of the bearing that is meeting the resistance. For example this bearing you have to press on the INNER race of the bearing. The case bearings you only use the out race to apply pressure to. Do NOT apply pressure to the balls. You wouldn't want it done to your balls

 

[1998rollover]

I used a pair of parallel jaw lock ring pliers, similar to this.