BW 4405 t-case problems

[CRUISERMEDIC]

my 97 ex with a 4.0 sohc, is having t-case problems.....some thing inside is causing it to engage the 4wd.....even when unplugging all elec. stuff. what gives? is this a rebuildable problem? and how easy is it to do? any one got a t-case for sale near the lansing michigan area? any help will be appreciated.

 

[CRUISERMEDIC]

bump....


i found a salvage t-case for 300 bucks.....thinking of doing this route, as a new one is around a grand. any thing i should do to the replacement t-case prior to putting it in...new seals, clean out old grease and repack....that type of stuff. looks like i just remove the cross member and the drive shafts unplugg some elec stuff and then undo mounting bolts...is this correct...about how loge does this usually take?

thanks, steve

 

[gijoecam]

Sorry for the lack of response.... holiday week and all...

Back up a second... what makes you think there is something wrong with the t-case to start with? What exactly is it doing that leads you to believe it's malfunctioning? The system should engage the 4wd at certain times as determined by some computer algorhythm stored in the electronics.

Now, you mentioned that it would lock up when everything is unplugged... what's 'everything' and which plugs?

It's pretty simple to troubleshoot.... we're happy to help out. We just need you to bring us up to speed on exactly what it's doing and exactly what you've checked and how you checked it so we're all on teh same page.

-Joe

 

[CRUISERMEDIC]

well i forgot to mention in my last post that i can hear something in the t-case making a grinding noise, the fluid when drained looks very black and smells burnt.....i didn see any metal flecks or any thing. and as for what was unplugged.....im pretty sure i got all the elec plugs off it. 3 or 4 of them couldnt find any more. im not sure what they went to exactly but i was sure they wwere sensors and the signal devices. same deal then....still a clunk in the rear and it does it much more when on the hoist. i off course put new fluid in before i ran it. this is my first 4wd vehicle but when i put into 4wd it is smooth as silk and is functioning as farr as i can tell. the clunk only happens when it does it on its own. not speed dependant or anything just happens when ever.....not on a shift point, no rpm fluctuation, shifts smooth as silk, drive shaft splines and u-joints seem fine ill inspect further when i drop them though

 

[CRUISERMEDIC]

is there a vacuum lockup device for this transfer case im not seeing bw 4405
f774 ga is the id number.

 

[blueexplorer212]

Im not sure on what tranzfer is what one so this my be a retarded thing but is it all wheel drive or auto 4wd ? If its all wheel drive on a lift its going to try to put in 4wd all the time thinking its sliping the tires. This might help but like i told you i am kinda new to explorers.

 

[CRUISERMEDIC]

nope its a part time automatic engaing 4wd with the electronic shift with the switch for auto, 4hi, and 4lo on the dash

 

[blueexplorer212]

So your saying it dont have a 2wd spot ? If it dont its going to try to go in to 4wd any time the back tires spin faster than the front tires do automaticly. As it gos in to 4wd it will make some sounds kinda klunky.

 

[CRUISERMEDIC]

correct no 2wd selection only the auto, 4hi, and 4lo. i dont think it shoud go into 4wd with all elec sensors and such removed from it. it shouldnt detect different wheel speed without them should it? and it is more of a definite clunk like some thing is locking up inside the t-case.....absolutley no clunk when i select 4hi or 4lo. i know this as i tried it and it seems to work fine on road and hoist. like i said i dont know what is in these t-cases.....i know a cluch pack some gears and a chain thats all i know......ill find out soon enough though

 

[CRUISERMEDIC]

and its like my rear end wants to "buck" like i ran over a good crack in the road only there aint no crack.

 

[blueexplorer212]

Well just a thought but it might be the front end makeing the sound it locks in and out just like the transfer does there is some vacum lines and wires that gos in the pass side tube. Might be the sound you hear becouse the drive shaft is not turning the right speed from the transfer stuff you un hooked. Not to say thats what it is but you might have to wait till somone that knows more about it looks at the post heh

 

[CRUISERMEDIC]

i do appreciate the advise.....i thought about vac controls but didnt see any right away when i looked under there and was unplugging stuff.....ill look again as i dont want to do a swap if i dont have to....i just hope nothing is wrong with front end from this deal.

 

[CRUISERMEDIC]

do you know if a vac must be interpreted by a sensor to cause a change to
4wd? if so i wouldnt think it would work. is the vac sensed from the front axle or from the t-case? forgive me if i dont make sense as its late in my 48 hr shift.

 

[gijoecam]

Again, sorry to chime in late here....

The 95-96 system is different than the 97-01 system. The later second gens do not have a vacuum-lock-up (aka Center Axle Disconnect) on the front axle.

Now, if you unplug the transfer case connectors and try and drive it, it's not possible for the case to lock up, however, due to the design of the clutch inside it, there can and generally is some amount of frictional force applied to the front half of the drivetrain and the front wheels will likely turn. I suspect that's a part of the reason they did away with the CAD on the 97-up Explorers as well.

Now, with the clunking when driving, are you talking about steady-state cruising? Accelerating? Decelerating?

The black fluid leads me to believe there's a problem there... it should be pink as it's trans fluid, not gear oil.

-Joe

 

[IZwack]

sorry for the late response too - holidays

Anyways, the transfer case does normally make a small amount of noise when its operating as the chain turns and turns - even when the vehicle is not in 4HI/4LO. As gijoecam mentioned and with all four tires off the ground, there is some 'drag' in the transfer case that forces the front wheels to spin even if the transfer case has been electrically disconnected form the rest of the vehicle.

If your vehicle is indeed going into 4wd on its own, your engine should feel like its going to die on dry pavement as you make a tight turn (tight as in you're trying to park into a parking spot). If this is true, the transfer case is really in 4wd and the transfer case is binding up as the front driveshaft spins at a different speed than the rear driveshaft (in a tight turn, the back wheels never follow the same path as the front - hence the bindup). If it does not bind during turns, then the vehicle is not in 4wd. Be careful about this test tho -- the moment you feel that its going to bind, turn the wheel the other way

 

[CRUISERMEDIC]

ok new scoop here.....I wasjust under there andi removed the plug that has the controlof tgagement of the front wheels.....the little switch for auto 4hi and 4lo....no engagement of front. i was mislead by some one that was working on it with me and he was under there and said he removed it....guess not. with this inplace the truck sensed it was on ice and ofcourse compensated with front wheels, next time illdoit myself. anyway i drove it for abot 1/4 mile and same klunking noise with a buck to te rear...no better and no worse. i did notice a leak of fluid from the front driveshaft area where it connects to the front diff. i assume its a pinion seal and i may need to replace bearing to. could this be a chain jumping teeth. any one have a exploded view of the inside of my case bw 4405 f774ga?

 

[CRUISERMEDIC]

ok i found the exploded view on here. what is the one black wire that leads into the right rear area of the t-case? f i need a new one the one im looking at was cut about 4 inches from the case i dont know where it goes as it goes right into the case. everything else has a plug. is this cut wire splicable?

 

[CRUISERMEDIC]

Now, with the clunking when driving, are you talking about steady-state cruising? Accelerating? Decelerating?

The black fluid leads me to believe there's a problem there... it should be pink as it's trans fluid, not gear oil.

-Joe

klunk is always when i am applying gas. dont happen when i push it....i mean if i pump the throttle it doesnt klunk klunk klunk in unison. it never has done it while decelerating/braking. it does it while cruise is on. basically it does it only when under load. when i had it up on hoist i ran it about 30 mph and she didnt clunk, put her on the ground and she was klunkin before i got out of my driveway. doesnt seem speed dependant although ive never had it happen if i was driving 75-80 mph or more. like i said before not on a shift point shifts are smooth. fluid for trans looks smells great. ive moved all kings of things back there to see if it was something other than the drive line....nothing is sloppy. if i put it in 4hi i still get the same clunk no better and no worse, 4lo works but of course i dont ever get it to klunk ithink cause i just cant move fast enough. i do appreciat the thins that are coming back to me

 

[IZwack]

ok i found the exploded view on here. what is the one black wire that leads into the right rear area of the t-case? f i need a new one the one im looking at was cut about 4 inches from the case i dont know where it goes as it goes right into the case. everything else has a plug. is this cut wire splicable?

The cut wire is probably brown - not black. This single brown wire goes into the back of the transfer case - typically around the rear output flange. That is the infamous "brown wire" - of which people use to do the "brown wire mod".