manual transfer case swap

[So-CalVX]

i found a 1998 trooper t-case for $100 dollars...
the question i have is... what would it take to swap out my TOD and install this?
i was thinking it would work because we basically have a short trooper and it came with or without TOD so why can't i have the manual selection instead of a computer controlled 4WD?
also... there are a few smashed up troopers available at any given scrapyard which makes this swap an easy fix if anything else breaks in the future

any input or ideas?

[tom4bren]

Not sure how much the TOD is tied into the main computer. As long as it mechanically bolts up you should be fine but you may get a bunch of CELs if all the sensors aren't happy.

Before you commit, check the TOD error codes, check tire pressure, check all electrical connectors under vehicle, check transfer case fluid level. Ya may want to go to a grassy or dirt area & do some donuts in reverse (really punching it). Whilst your at it, try exercising the ABS - prolly not associated but it never hurts to try.

[So-CalVX]

ABS went out about a year ago...
i'm gonna disconnect the batt while i go to the scrap yard to check that silver vx for a transfer case (and other lil doodads)
then when i get back... if she hasn't fixed herself, i'll take the bee to my buddies garage to see what is up
i will check all connections under nieth and try that reverse donut trick

i think my tod is finally getting back at me... we've never had any disagreements when it came to tread depth or air pressure and once i ran over the fire hydrant everything slowely got worse and worse

oh well, atleast i own it... i can buy something cheap and put this monster on the back burner till everything falls into place if i need to

[Triathlete]

Might want to check in over on the Planet to see if anyone there knows if any other t-cases are interchangable. There is a wealth of Zu knowledge over there.

[Knivx]

I'd be very interested to know this as well because I've had these same thoughts rattling around for awhile. Nothin wrong with my TOD (doesn't work in reverse? thats normal right?) I just would like to have the option of 2wd and 4wd lock not to mention low range kits. Plus I see it easier going to a solid front axle without the TOD.

[So-CalVX]

ok.. i disconnected my tod computer 3 different ways...
1) small connecter close to driver - engine revs with brake applied lights still on (afraid to test drive with brake acceleration)
2) large connecter close to passenger door - lights off and two wheel drive (rear wheels) no problems yet
3) both connectors - same as 2

anybody have any advice, warnings, tips or criticism? speak up

[RamAirZ]

Ya me and him discussed this swap not long ago via PM, I think he just wants to get rid of TOD (like me). I like having 2wd as an option as well as 4HI, that and the availability of lower gears is a nice option too. We already confirmed that he can bolt everything up and go, the only sensors that would be screwy would be for the TOD itself but if he already has those problem, well then he probably doesn't care lol

[BigMeatVX]

Hmmm

Ok I was just making sure he realized that he could have 2WD and normal TOD and 4WD-HI range....all with the TOD case he already has...


I have disassembled a TOD case and I can assure folks how it works both internally and externally....

I will start a new TOD thread soon, with detailed pics of the inside, showing how it functions....AND describe different ways to modify it to folks liking...
Also, some cool new tricks to allow different torque splits at will....

[RamAirZ]

Wasn't someone working on that before and figured out the electromagnetic clutch portion would always transfer a little power to the front or something? Would be awesome for some folks to be able to have 2wd, 4hi, 4lo and normal tod, be nice for 2wd on nice sunny days but pop it in tod for rough weather (snow, rain etc) without being in full 4wd. I like having the simplicity of the manual case and then I can drop in some lower t-case gears.

[BigMeatVX]

Yes well sort of....

With TOD disconect switch, I am in 2WD mode....I can spin the rear tires endlessly, at will, W/O the front getting any REAL torque....the front is VERY disconnected in this mode....

ON the Dyno, folks HAVE had issues with the front wanting to pull a little bit, BUT this is with the front tires sitting still and the rears spinning at 70+MPH!!!
Difficult to repeat in real world driving....

With the TOD 4HI modifacation, you will have 50/50 torque split, (with no delayed grabbing) and this is a one wire mod!!!!

Normal TOD....we all know how that performs....
4Lo- 50/50 LOCKED....TOD is off...

There were some folks, a while back, that were working on a Pulse Width Modulation controller that would have SUPPOSEDLY allowed variable torque....0-50% to front axle....But that plan was scrapped a while ago???....

Nowdays, after tearing into a TOD unit myself, I can indeed see how simple it is to design a modifacation that will allow a steady 30/70% torque split as well, and possibly a few other pre-determined ratios....20/80% ect.....

I may even modify my current TOD unit, so as to remove the shift fork that locks the 4x4 in low range....In other words, I want to experament with LO-Range TOD....I feel that that the clutched design can and will save my CVs!!!! as the multi-clutch plates would absorb much driveline shock!

[RamAirZ]

I've read the write-up Tad did over on the Planet for the 4HI switch, if I change my mind and keep my TOD I was planning on this. Look forward to seeing what you come up with, I have manual hubs up front now and can spin my tires pretty freely as well but of course it's not real 2wd. I thought I read on here that even with the TOD off switch you still send SOME power up front but still, it's less than without it so that's always a plus.

[BigMeatVX]

Im uploading a few pics of the internals for folks to gaze at...lol...

There is a detent spring that holds all the disks in the free position, when there is no power going to the coil (elctromagnet)...SO....there should be very little, if any, power sent thru the front driveshaft in TOD disconect mode...UNLESS of course you incur some sort of drivline shock/torque that could overcome the detent spring....

Here are a few pics...notice the 3 balls that sit in the "bevelled ramps"
Pic 2 is ramp down or 2WD
pic 3 is ramp up or 4x4 50/50 split

[BigMeatVX]

The coil (elctromagnet) actually pulls the back plate away, allowing the balls to travel up the ramps ....


As the balls travel up the bevelled ramps, the two plates get wider...this puts force on the many clutch disks...the harder it turns (driveline torque) the farther up the ramp the balls go and the more force on the plates!!!!

[RamAirZ]

very interesting! Makes me want to go tear my tranny out lol. I love tearing things apart haha, of course putting them back together is always fun too

[So-CalVX]

big meat... my TOD decided to lock up permanently while i was wheeling out on some rocks at the beach... i tried everything listed and other things to get it back to normal but it wouldn't go so i unplugged the computer and that put me in (what i'm assuming is) 2wd. i'm sure the front end is still spinning as i left everything connected but when i disconnected the computer i was no longer locked and i could do burnouts (which i couldn't do with the tod on)
so i am looking for the more info like ram air and i have been chating about on swapping in a roddeo/trooper t-case
from what i recollect i can bolt up an early 90's t-case from either and get a custom longer front shaft and i'll be golden... so i'm looking into that
by the way... i love seeing the insides of anything mechanically relevent to my baby... keep those interesting pics coming