How to: The Borg Warner 4405 Transfer Case Rebuild Diary

[GusBrazil]

Thanks Wolfgang,

Actually, I just discover that it was broken when I needed it (in a beach sand).
When I got back home I realised that the turn on button was disconnected
and when I connected again it starts making the crackling noise.

Any ideas why it was broken?

I am having a hard time to find a new part but fortunately I found a used one
down here in Brazil.

Take care,
Gustavo.

 

[wollimann]

reason why this part brokes

Hello Gustavo,

i don't know the reason why this part brokes, but maybe your transfer case is worn out. Many problems appear at 150 thousand kilometers, more or less.

I could imagine, that your clutchpack is down and/or the spring brokes and one of this 3 steel balls jumps out of his notch. If the magnet coil gives pressure on the APPLY CAM again, there is irregular power and the APPLY CAM broke -> maybe the reason?

Nice to hear, that you found that (used) part in Brasil. It's like in Europe, no parts available -> everything i had to order in the USA.
But the Explorer is worth the efford, he is a reliable fellow.

Good luck

Wolfgang

 

[GusBrazil]

But everything you said seem fine when disassembling it the only thing that was worn is one of the fork bushing.

Here in Brazil is also difficult (and expensive) to find parts. I usually buy it over the internet.

 

[matbrandt]

Clutch pack discs

Hello my friends,

Sorry to bring an old topic to the top, but....

I am with a problem in the assembly of my 4405. Initially when I opened it, I saw that the discs were worn, but when I removed it had only 5 discs each with a pair of metal discs totaling 10 discs. But when I bought the part from Cobra Transmission in Miami, it came with a 12 discs kit, the first difference I noticed also is that the disks that were on my 4405 had only one side with clutch, and the new I bought had 2 sides with clutches. Anyway, the 4x4 worked normally but when I accelerate (we note that it is precisely when the 4x4 turn into operation) i'm hearing a very loud noise, and a bump, it seems to be from the transfer case itself. I will disassemble again and re-assembly it with 10 disks, the to see if the problem solves, but, anyway, how many discs are? this can vary from year to year? could be other problem that i missed????

mine is a 1998 Explorer V6
Thanks

 

[wollimann]

Hi,

my clutch pack exactly counts 10 disks

What you can get, for example at EBAY
has also 10 disks

Don't believe that it vary from year to year,
maybe you ordered/or they send the wrong pack?
With 12 disks it should be impossible to close the clutch pack perfectly?

Wolfgang

 

[matbrandt]

Hi,

my clutch pack exactly counts 10 disks

What you can get, for example at EBAY
has also 10 disks

Don't believe that it vary from year to year,
maybe you ordered/or they send the wrong pack?
With 12 disks it should be impossible to close the clutch pack perfectly?

Wolfgang

Wolfgang,

Thanks for the quick response and the pics. The discs i have ordered are exact like the discs that you sent me from ebay, but, they are 12 instead 10 that i removed from the t-case, believe, the clutch pack has closed perfectly with 12 dics....For now, i can count on the pic that you sent me from the ebay, 11 discs, am i crazy?? . Yesterday, i finish mouting it with 10 discs, and tested today, and now theres no traction on the front axle. Ive taken a better look at the chain on transfer case, and seems to me there's a little a gap on the chain, do the chain works tight, or theres really a gap on it? I'm starting to think this may be related to the bump and the noise....

Thanks!

 

[wollimann]

Hi,

you dont have made any pictures of your clutch pack, chain an other parts?
Where did you recognize a gap at the chain?
Here's a original chain without any gaps.

If the chain is lengthen too much, it could jump over the gear-wheels,
this causes a short bump.
For normal the chain must be tight and didn't have any sag.
Did you dismount the transfer case, or did you try to fix it under car?
What did the label on your TC shows exactly?

Here you can take a look (maybe reading) for my BW4405 F77A-7A195-GA
with elektric shift motor and speedo gear.
http://www.explorer4x4.de/viewtopic.php?t=18457

To find out what's about the amount of clutch discs, you should ask a professional member by PM (Glacier991). I am not a professional, writing bad technical english and coul only talk about my TC.

There are so many sources of error for this 4405 (e.g. coil, chain, shift fork, bearing seats, sensors, oil pump) that is hard to identify your errors.

Greetz

Wolfgang

 

[matbrandt]

Hi,

you dont have made any pictures of your clutch pack, chain an other parts?
Where did you recognize a gap at the chain?
Here's a original chain without any gaps.

If the chain is lengthen too much, it could jump over the gear-wheels,
this causes a short bump.
For normal the chain must be tight and didn't have any sag.
Did you dismount the transfer case, or did you try to fix it under car?
What did the label on your TC shows exactly?

Here you can take a look (maybe reading) for my BW4405 F77A-7A195-GA
with elektric shift motor and speedo gear.
http://www.explorer4x4.de/viewtopic.php?t=18457

To find out what's about the amount of clutch discs, you should ask a professional member by PM (Glacier991). I am not a professional, writing bad technical english and coul only talk about my TC.

There are so many sources of error for this 4405 (e.g. coil, chain, shift fork, bearing seats, sensors, oil pump) that is hard to identify your errors.

Greetz

Wolfgang

Wolfgang,

Unfortunately i didnt take any pics of my transfer case open, mine's have the speedo, but is not in use, i didnt find any cable or wire to plug in, and the speedo works fine without it.

I've removed the t-case from the car and dismounted it. At this time it is mounted and working only on 4X2, because i am in need of the car but i will disassembly all again this weekend, when i get the new chain, and put the 2 discs back again. I thought the chain was loose because when i press it with my finger i can feel that the chain has a gap, its not like yours on photo. Im not a professional too, but i liked so much of your work in the German forum, I'm lucky that I can read German. I'll read it slowly your whole process of disassembly the t-case.

I took the liberty to take this diagram that's in your post from another forum where exactly show the amount of discs. Clutch discs are 5 and flat discs are 6, totaling 11! I believe that i put on disc more on first time, and now 1 disc less.

Thanks for the help, anyway!

 

[wollimann]

It seems, that someone else (yourself?) mixed the TC of a 97 Explorer with a 98 chassis.

If your speedo works fine, your speed signal comes from a sensor located in the rear differential.

If you found 7GA (F77A-7A195-GA) on your TC label, for my opinion you need the chain shown above.

If you found another number on this label, someone else only uses the rear transfer case half of a 97 TC. Maybe the output rear bearing seat of the original TC was worn out.

So be carefull by ordering the matching chain (Borg Warner by Morse TEC),
available with different width i believe.
Here an offer with chain and overhaul Kit:
http://www.ebay.com/itm/Morse-Chain...rd|Model:Explorer&hash=item58a7a70fe0&vxp=mtr
I ordered my parts here
http://www.manualtransmissionpart.com/BW4405.html
there are 3 different chains!

Nice to hear, that you can understand german. In germany the Explorer is still a "exotic" vehicle. Only a few professionals are left, who have the experience to repair the motor (timing chains), the transmission or the TC.
Only a small amount of OEM spare parts are left in some storehouses, for horrible prices.

So you are in a much more better position and i hope you will bring him back on the road again with a well working TC.

My Ex is waiting or a complete new front suspension since 3 weeks and the front frame is very rusty. Have to restore frame and the main crossmember, that takes time. So i can comprehend, that you need your car.

Whish you the very best!

Wolfgang

 

[bryansr]

Anyone else having trouble viewing page 1 of this? I'm ready to put mine back together, and would like to see it step-by-step, but it appears the advertisements on the images are hanging it up!!.....

 

[bryansr]

Anyone else having trouble viewing page 1 of this? I'm ready to put mine back together, and would like to see it step-by-step, but it appears the advertisements on the images are hanging it up!!.....

I figured it out. It was my IE security settings were set too low.....

 

[EXSPORT97]

97 Explorer 4wd troubles!
Hello everyone, newbie to the forum and like what I see so far. Ok here is what is going on... I bought my 97 Ex sport 4.0 sohc 4wd knowing the 4wd did not work. After doing a lot of the troubleshooting and tests I've read in previous threads, I came to the conclusion it was something internal in the TC. In 4hi and 4lo it would only drive the rear wheels, no flashing 4wd lights, as they were working properly with mode change. I can hear the shift motor changing also, and would drive in 2lo. Even on jack stands the front driveshaft nor the wheels would turn only rear wheel drive.

Pulled the TC and tore it down and the plastic ring was in a dozen pieces and the clutches only had one side of material. So I replaced the clutch pack, inspected all the other areas. Put it back in and still not wanting engage until I would give it some gas pedal. You could hear the clutch locking up when I would gas it in 4hi and 4lo, but would only pull the rears idling in drive on jack stands..

Sorry for the novel, just trying to give somebody the best info I can.
Any help would be appreciated!!!!

Thanks,
Sean

 

[wollimann]

I would prefer to measure if there is any voltage on that brown wire which goes to the coil (462 in the detailed picture above).

Another fact is, that the system maybe can deactivate the 4 wheel drive
to prevent bigger damage to the TC (no 4x4 lights flashing).
If this is the reason, only a garage or Ford daeler with the matching software could reactivate the 4x4.

Another fault could be the elektrik part (under the blue or gray plastik cover) of the shift motor, which tells the system the position of the TC.
Some corrosion inside could cause the systenm to fail.
Unfortunately you could not change this part seperately.

Or the three little steel balls (486) are not right in place, so the clutch pack can not get pressure while the coil is in action. And maybe the spring (974) is broken which causes less pressure on part 574.

Did you find any metall pieces inside the TC or on the magnet?

It's a nervous play i know, but you will get it fixed!
Let's stay us informed.

Wolfgang

 

[EXSPORT97]

Thank you Wolfgang for the reply!

Yes there is 6.4v at the brown wire going to the coil.
And there were no shavings on the magnet next to the pump filter. The spring under the ball ramp was in good shape as well as the ball ramp plate. Just the clutches were worn.

Thank you,
Sean

 

[wollimann]

OK, there is electric potential, a good sign.
Now something cause the coil to get not much more potential.

I don't know only some considerations, take of the shift motor and switch the shaft to high or low by hand, give 12V (seperate connector) on the coil, the clutch should close and you can try to turn the front drive shaft.

There is a modul which is responible for this.
Involved are the two sensors of the TC and the electric position modul of the shift motor.
(Sometimes there is corrosion in the cable connector)

A broken plastik ring inside also could cause faults.#

Before you open the case make marks.

Thumbs up!

Wolfgang

 

[wollimann]

Hi Sean,

did you have any news about your transfer case?

Greetz

Wolfgang

 

[cocofish]

hello I would like to KNOW if I can help What is the function of the coil Going WITHIN THE trasfer and Ranging two Que decompose me . and if the new sell ???
anyone know where I can buy a trasfer recostruido in mexico ,
or trasfer manula

 

[cocofish]

know that model explorer you can put the trasfer my explorer 's 1996 handbook as no longer meeting in mexico if any will be adapted or the trasfer of 2000 explorer is the same just change the outside ???? ???????

 

[np63om]

Thanks for this usefull post. Thank you so mutch

 

[Benjamin265]

Digging up bones...
Thank you for this post. It will be much appreciated in the days to come.
One correction however. The AWD is a magnesium case. You mention it's all aluminum.