Hybridized 4405 T-case (97 and 98 parts) > stuck in 4hi - (Great Pics of the 4405!)

[IZwack]

Hybridized 4405 T-case (97 and 98 parts) > stuck in 4hi

hey all,

my brother's 97 40 sohc eddie bauer's transfer case (BW-4405) was making a funny sound so we pulled it the other day and cracked it open.. the tcase sounded like the chain was slapping against the casing itself.. so we purchased a new chain.. however, we also found this thing cracked in half:

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one of the friction plate's friction material also disintegrated upon removal.

so we had a few parts to replace. luckily, a long time ago, i switched to a manual BW 1354 so i no longer needed my electric shift 4405 and its been sitting in the shed since then. of course, the easy thing would be to swap my 4405 (from my 98 X) to his 97 X. Problem is, in 98, the 4405 model had a few changes compared to the 97 and below models. Among other things, unlike the 97 4405, the 98 4405 has no speed sensor at the rear output shaft - so swapping that into the 97 would mean a dead speedometer (which is what happened when we tried it). so the only other option was to rebuild the 97 4405 using some of the 98's parts.

well so i did the rebuild - replacing that cracked gear pictured above with the gear from the 98 4405, and also the friction plates set on the 97 4405 were replaced with the set from the 98. but now it seems that the tcase is stuck in 4-hi. I dont think the electromagnet is being powered up so thats not the problem, but rather the friction plates are being engaged prematurely (when they shouldnt be). here is a shot of the two different friction plates set:

im thinking that the friction plates, or something in the entire clutch system is thicker than the original - causing the entire clutch pack to engage the front output shaft. anyone know whether or not the 98's 4405 friction plate set is thicker than the previous years? or any other part in the front engagement system?

oh and also, anyone know what the torque spec is on the rear flange's nut?

 

[IZwack]

bumpity

 

[88mustanggt]

oh i am in the same plase you are, broke same peace and am in a half my 97 case and half a 99 case but mine only engages hi and low to the rear tires not the front

 

[IZwack]

ahah hey there, i didnt think anyone else would try this or even reply to my post..

anyways, im assuming that you are driving a 97 and ur donor transfer case is from a 99? my situation was very similar except my donor case was from a 98. anyways, the simple solution that i went with was just simply swap the rear halves of the magnesium case and use everything else from the 99 transfer case... so basically, in ur situation, rebuild the 99 transfer case using only the 99's parts, but instead of using the 99's rear magnesium housing half, use the 97's rear housing half..this will give you the sensor output that you need at the rear output. it worked for me so hopefully it will work for you.

 

[88mustanggt]

yup thats what i did, but no 4 high or 4low out front , the rear goes to 4 low and i can stop the front driveshaft from spinning when its in 4 low. and that shouldnt happen. i dont think the clutch is engaging correctly

 

[IZwack]

hmm are all of the friction plates in? are the three little balls sitting in the groove? did you put that one bearing thats about 3/8 of an inch thick at the rear output shaft?

 

[88mustanggt]

hmm whats this bearing look like? that sounds liek somthing that would do it.

 

[IZwack]

​

 

[Chris97Exploder]

I'm getting ready to do this too!
I bought a 99 t case thinking it was the same and found out the speedo sensor was moved, my explorer is a 97.
Can't I basically take the back half off and just set it on the 99 once its back half is removed? I guess I don't know the sequencing to splitting the case pertaining to what comes apart first.

Any helpful hints are GREATLY GREATLY appreciated!

Thanks,
Chris

 

[IZwack]

your right, you can just swap out the back halves.

splitting the transfer case is pretty straight forward tho there are a few tricks that may make it a little easier for you. you probably already know most of what i'm going to say but i'll say it anyway for future readers or whatever.

first off, get your vehicle on a flat surface and block off the wheels. remember that after the driveshafts are removed, there's no more drivetrain holding your vehicle still - so block off the wheels but still keep your shifter in the "Park" position.

then remove the front and rear driveshaft and disconnect all wires going to the transfer case. there is also an overflow tube that will probably be attached to the vent fitting at the top/front of the transfer case, remove that also.

i find it easier to remove the transfer case shift motor now because there's really not much clearance between the shift motor and the gas tank when your trying to slide the transfer case out - so this one is up to you.

while the transfer case is still on the vehicle (and the vehicle in "Park"), loosen the nut thats holding the rear output flange onto the tranfer case. this nut is quite the toughy so its easier to loosen it now when you have the transmissoin help you hold the nut from spinning. After you break it with a breaker bar, spin it about 3 or 4 full turns out so its lose but still on the transfer case.

(note the image above is of an electric/automatic BW-1350 transfer case as i don't have any images of a BW-4405's rear output - the only difference should be the shape of the casing - the 4405 has "ribs" where as, as you can see form the image, the automatic 1350 i had was smooth)

after that nut is lose, go ahead and start removing the bolts that hold the transfer case onto the transmissions tail housing. i think these bolts are all 13mm ("half an inch" for those still living in the dark ages- ehehe). start off with the ones at the very top - the hardest of the bunch will be the top one on the passenger side - the exhaust piping and all this other stuff will be in the way. the easiest method i found was to use a socket wrench with about 1.5-2ft extention and a universal-joint socket at the end. a universal-joint socket set looks like this

as an alternative, you can also use a universal-joint adapter and use a standard socket after that. these adapters look like this:

now move on to the other bolts and do the bottom one last. before you do the bottom bolt, have a pan ready to catch transmission fluid because some transmission fluid does overflow into the tailshaft housing and this will leak out once you start separating the transfer case from the transmission. so go ahead and unbolt the last bottom bolt - note that this bolt probably wont come out all the way because there's not enough room to completely remove it as the transmission mount (i think) is in the way - but go ahead and unscrew this bolt so that its free from the transfer case.

chances are, the transfer case isnt just going to separate itself from the tailhousing of the transmission cauz the gasket will keep the two stuck together - so, with a pan in place right under where the transfer case meets the transmission's tailshaft housing, go ahead and give the transfer case a nuge towards the back of the vehicle just so its separated from the transmission by about a millimeter or two. at this point, transmission fluid should be leaking out quite a bit and itll take probably 10-15 mins till the fluid stops flowing/dripping.

now for the delicate but brutal part - while supporting the transfer case's weight, you have to slide it from the transmission's tailshaft housing and from the transmissin's output shaft. the transfer case has to slide back maybe about 1.5-2.5 inches before it completely clears the transmissin's output shaft - support the transfer case's weight during the entire process because you don't want the transmission's output shaft to be the one supporting the transfer case's weight! i find it easiest to support the transfer case with my knees with something in between my knees and the case (a rubber floor mat works well) - but be careful because the transfer case is fairly heavy. once it clears the transmissin's output shaft, you may have to rotate the transfer case to clear the gas tank but it should come down fairly soon if it hasnt already.

so now uv gotta take this transfer case somewhere fairly clean so that you can work on it. use a hand cart or something - no need to break your back (especially since the electric shift cases are heavier than the manual ones).

so now completely remove the rear output pinion flange from the transfer case. note that there are a few things that come with the pinion flange - mainly the nut that was keeping it in, a washer, and a rubber O-ring that may or may not fall out. make sure you keep track of these little things - as well as other things during the entire process cauz there will be quite a few of them.

going around the transfer case, start cracking the torx headed bolts that keep the two case together but dont completely remove them yet. just give them one or two twists to make sure none of them are frozen onto the magnesium housing.

with all torx-bolts lose, position the transfer case so that the output shaft (who's flange you just removed) is vertically facing up. in this position, the input splines (that connect to the transmission's output shaft) of the transfer case should be facing down (if your working on a hard surface, support this with something softer like wood or a mat). this also means that the transfer case's front output is facing down. the front output doesnt protrude out as much as the input splines so you might need a small piece of wood or something to support that flange in order to keep the transfer case fairly level.

now the torx bolts should all be facing up - start removing them from the transfer case and put them in a ziploc or someting because there are many of them and the chances of losing one or two is fairly high.

after the torx bolts have all been removed, u can now officially split the case. if the transfer case doesnt split very easily, there are a few flat tabs on both sides of the magesium casing - put a pipe or a breaker bar between the two and torque it so as to split the two halves apart. as for removing the upper half of the casing from the lower half (remember we have this thing turned so that the transfer case's input flange is facing down), try to lift vertically and not side to side because the shift rod mechanism is very delicate and easily snaps if you put any side lateral force on it. the image below shows two shift rods, one broken and obviously one thats not.

sometimes the shift rod will come up and out with the top half so be careful when removing the top half of the casing - go slow.

so now the only thing that you need to do is put the other magnesium half-casing on and everything is in reverse order. dont forget that you need RTV between the two halves. but before you apply RTV, practice getting the two casings back together because the RTV might cure before you get it right the first time (cauz sometime the top half dosnt just slide down). so practice getting the two halves together, and once you get it right and feel confident, then separate the two and then put the RTV on.

in case the shift rod does come out of position, here are a few images to help u reassemble (these are taken from other threads ive posted so u might not understand why some are labelled the way they are):

and in case you do break a shift rod, dont forget you have two of them (one from each case) and, as you can see from one of the images above, they are similar (the broken one is from a 97 case, the other is from a 98)

 

[IZwack]

i just realized that the 99 transfer case that you have probably isnt on a vehicle so removing the rear output flange will be a challenge... try putting a few of the bolts that held the rear driveshaft to this flange back onto the flange but on the other side of the flange.. this way, a bolt (or two) should be caught on a part of the magnesium casing when you start removing the nut. be careful tho, magnesium, like aluminum, is somewhat brittle. the other option is to temporarilly attach the 99 trasnfer case onto ur vehicle and crack the rear output flange's nut there. if anyone out there has any other suggestions on how to remove this nut while the transfer case is off of the vehicle, please throw in your two cents cauz i had one heck of a time removing it.

 

[Chris97Exploder]

Thanks for the write up!
It really helps to know what to expect when I crack it open. I've swapped T Cases and trannies before (never swapped internal parts though) so that should be relatively easy!
I'll let you know how I make out.......Thanks again!

 

[88mustanggt]

ya i removed the nut with it not on the car. i just used an impact gun worked great. to be honist i cant remember about the bearing, i asume its in there. i really dont want to drop the case again and open it up and put it back together and hope it works. im just trying to find another one that is the correct one now. if the new one works i will deffently open the old one cause i am still curiouse on what i screwed up in there to cause the case not to transfer power to the front wheels. only slip a little power.

 

[IZwack]

i really dont want to drop the case again and open it up and put it back together and hope it works

yeah i gotcha, it is rather heavy huh? here's a picture of me after i had to drop and put back up a transfer case 4 times in a row:

ahaha, what a governor!

 

[88mustanggt]

its not so bad it only takes about 40min to do it now, i can do it at my work on a lift with power tools, and someone else to help me bring it down and bring it up. bty do you know the answere to my other post, a few post down. im gona try to get a case tomarow but have to drive 200 miles to phx to go junk yarding, theres only one yard up here and they want 1000 bucks for a freakin used tcase

 

[IZwack]

bty do you know the answere to my other post, a few post down.

sorry i couldnt find ur question, please restate

 

[88mustanggt]

what is the diffrance between the 3 diffrent models of 4405? my tag broke off so i dont know what one i need to be looking for. thers like ga ca and r_ somthing,

 

[88mustanggt]

oh and i broke the shift rode exactly like you did on my first try to hahah, and that peace at the top of the page the first time i put it together and put the truck in gear. so i wouldnt doubt if the problem of yours stuck in 4high and my problem of not puting power to the front might be by the same type of mistake

 

[IZwack]

what is the diffrance between the 3 diffrent models of 4405? my tag broke off so i dont know what one i need to be looking for. thers like ga ca and r_ somthing,

sorry i dont know all the differences between the models. all i know is that there was a switch between 97 and 98. among the other things discussed in this thread (as well as others) such as the sensor on the output,according to Ford - the chain between those two years were also different. hopefully some1 can chime in on the differences - gijoecam knows a lot about transfer cases so hopefully he can say something about the differences.

oh and i broke the shift rode exactly like you did on my first try to hahah

ahah yeah, its fun isnt it? when you hear the faint tick and depression sinks knowing that yes, it has indeed broke.

 

[88mustanggt]

can i ask does your case have a speed sensor and what model is it? is it a ga? (f77A)
well thats the one i have been askin for thinking it might be the one im after but im not sure.