Non-functioning 4x4?

[Bombadier]

just rebuilt my driveshaft, new cv, new yoke and pinion oilseals, and while i was at it, had some new vacuum lines put in to my Edrive switch, and installed a better one that didn't leak any.....mechanic said switch works, and locks up the tcase.....heard some funky grinding noises on the way back home last night, went back to the garage, of course, no noise again......
so today it rained good so i went on lunchbreak to a dirt field behind my work....parked, locked the hubs, got back in, put it in neutral, flipped Edrive switch, into drive, gassed it.....nothing! :mad:
front tires not spinning at all, and my back wheels dug into the mucky clay and i almost got stuck :mad: ......
so, i got good vacuum, switch doesn't leak, but
A. i can't tell if my tcase is locking/unlocking
B. what else, besides a vacuum leak, can keep my Edrive from working?

[River Beast]

Hold up!!!! You said "...had some new vacuum lines put in to my E-drive switch, and installed a better one that didn't leak any..."

then said, "...parked, locked the hubs, got back in, put it in neutral, flipped Edrive switch, into drive, gassed it.....nothing!"

Do you have a part-time kit with the QT unit?

if not... your hubs should be LOCKED AT ALL TIMES unless you run E-drive ALL THE TIME with hubs UNLOCKED....

running a factory QT (no P/T conversion) with unlocked hubs will destroy the center diff of the QT unit by allowing the brakecones to slip and really you should move anywhere...

can you ellaborate a little more...thanks

If anything....(not to curse it) Sounds like the shop put the lines on the switch backwards... allowing you to THINK it was in normal mode, when in actuality it was in E-drive...since your hubs were UNLOCKED and you were able to move... this sounds like the only logical thing to me.

when you flipped the switch (now in normal) thinking you were in E-drive.... you locked the hubs and nothing.... this could be a sign that there is serious problems with the senter diff of the QT brakecones being completely shot....

I don't mean to scare you any, but what you described is what leads me to think this way...sorry. :( :eek:

Like I said ellaborate a bit more...

[Bombadier]

my hubs are warn locking hubs, '77s didn't come factory with warns, did they?
thing is, with hubs locked, the switch doesn't seem to do anything, no noises from tranny/tcaseand, no binding when turning corners...and i've tried getting my frontend to lock up on both pavement and mud.... :confused: :confused:
.......
when i bought the truck, the hubs were unlocked and the DSPO told me to run it like that unless i was in good.....then flip the switch and go, but it prolly don't work anyhow.....
.......
right after i had my driveshaft/cv/yoke/ujoints replaced/rebuilt, i got a nasty grinding when taking off once, once at speed, and once pulling into the garage to get it checked out....of course it won't repeat again under same conditions..... :confused:
dunno, this is turning into the mystery mobile for me.....
is there any way to tell for sure if i have a part-time in my truck?
thnx RB

[River Beast]

With hubs UNLOCKED crawl under to see if you can turn your front shaft by hand FREELY... if so... you have a P/T conversion kit.

If not... you have a F/T QT

NOW... do me a favor...go under to see if both shafts are offset to the pass side on the t-case end... the rear shaft should be offset just like the front...

[Bombadier]

yup, hubs unlocked i can turn my front driveshaft by hand.....and both are pass. side offset......
now if my vacuum switch is backwards (i wouldn't be surprised), and it actually locks up my tcase, i shouldn't be able to turn my front shaft by hand, right?
thnx again!

[River Beast]

Sounds like you have a P/T kit in there...that's a good thing! WHEW!!! ;)

Now... in NORMAL mode (no light in dash..BTW,does the dash ligth work?) you should be able to spin the front shaft freely...

E-drive position, the shaft should not turn by hand hubs unlocked at well.

If the switch is backwards, just reverse the red stripe vac line with the white stripe vac line on the back of the va switch... OR reverse them on the QT diaphram...

Now... make sure you trace the lines...from the switch, they go thru the firewall... the lines are all together and smaller than every other vac line undere there and come thru right behind the intake... one (all black, no stripes) goes directly to the intake. The other 2 shoot into metal tubes just below the intake, down the firewall and back over the top of the QT to the diaphram.

Ensure all the lines are good, not blocked off or torn... they tend to dryrot and crack after time

[MONOLITHIC]

if the light dosnt come on (due to blown bulb) will this light effect the circut preventing actuation?

[joe]

Originally posted by MONOLITHIC:
if the light dosnt come on (due to blown bulb) will this light effect the circut preventing actuation?If you mean will the blown light keep the x-case from going in/out of e-drive...no. The x-case is shifted via vacuum.

[MONOLITHIC]

Thanks I didnt think so .Some alternators are that way no alt light = no charge .

[Bombadier]

lol yeah....WHEW smile.gif
all the vacuum lines coming from my edrive switch are brand new, but all black.....so come daylight i guess i'll just trace 'em down, maybe switch 'em around and see what happens.....i thought about what i did EXACTLY when i tried switching into edrive.....first, i had stopped in a grass parking lot to lock my hubs....just down the street was my test area/claymuck lot, and just before i got there, there's a small curve and i remember my front wheels chirping while turning my wheel.....I TOTALLY FORGOT ABOUT THAT :mad: .....so i'm figuring that my lines are reversed OR the rubber diaphram actuator thingy is shot, preventing my edrive from working......JOY!
:rolleyes:
and no, my 4wd light doesn't work....actually, i'm surprised ANYTHING electrical works at all...
so....next question.....i still have 4x4 if my hubs are locked and my edrive is NOT engaged? it's just not 50/50 power front and rear, is it?
what i don't understand is why people put P/T kits in these trucks to begin with....if they were designed to be full-time 4x4....was it to save gas, tires, etc??? :confused:
And is there an easy way to go back to NO P/T?

[ August 10, 2002, 10:55 PM: Message edited by: Bombadier ]

[River Beast]

If your tires chirped around the corner... it was most likely engaged... front ends on the QT equipped FSJ's were open diffs so only one wheel will spin anyway...depending on which one loses the taction first.

P/T kits were designed for tow reasons IHMO... gas savings (fantasy) and for those who neglected the QT and destroyed them by running the wrong fluid and tearing up the brakecones and center diffs.

I would not recommend converting back to a F/T unless you know for sure that the center diff you get was in GREAT SHAPE...

I did find a company that sells REBUILT QT center diffs for $325... $125 core charge

http://www.willys.net/html/transfer_case.html

[Bombadier]

discovered something new today.....only my passenger hub will lock.....the driver's side doesn't engage for some reason..... :mad: .....
once again i headed to my mud area and locked my hubs....just to be sure they were engaged, i grabbed my d-shaft and tried to rotate it, and it would rotate maybe about 10-15 degrees, then stop......HMMMMMM, that shouldn't happen....
so whatever my t-case is doing now, i can't be sure of anything until i get that hub fixed....
any suggestions on what to look out for when repairing a hub that won't lock???
and thanx for the link.....that should come in handy someday, hopefully not anytime soon, but i know Murphy too well.....
.....
have a safe and enjoyable drive to Ouray.... tongue.gif smile.gif , wish we were going!! :rolleyes:

[Bombadier]

would i be better off just buying new hubs, or is the one not locking indicative of a larger problem?

[Bombadier]

update-
i took off the one hub that wasn't locking.....
Whoo-boy, that thing contained a LOT of muck and nasty stuff.....no wonder it wasn't locking.....
So after torquing off on the the allen bolts, and a lot of swearing trying to pop the hub off, i finally got the thing all cleaned out....didn't have time to get to the other side.....
So i figured, yay, my hubs lock now, so i go to a nearby sand lot.....lock them hubs up, step on it.....nothing again....
fiddle with e-drive switch, again i hear nothing from my transfer case indicating anything is working.....
so i figure i'll start doing some slow figure-8s and actuate the edrive switch at the same time, maybe i can get it to lock that way.....
nah, i hear a nasty grinding noise instead....
what gives?????
the switch must be doing SOMETHING, because if i leave it in 2wd mode, everything's copesetic, but when i tested the edrive switch out a couple times up and down my street with the hubs unlocked and locked, i hear a strange whirrring/sand-in-bearings sound from directly underneath......

:(

[ August 24, 2002, 01:36 AM: Message edited by: Bombadier ]