Transfer Case

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chui

chui

10 Year 15 Year
Joined
Jun 3, 2009
Threads
25
Messages
73
Location
Kenya
Website
www.zenosafaris.com
Hi,
Any suggestions on how to get my BJ 74 transfer case working. Its a vacuum system but have changed switches but still 4 low does not function.
Is there a way of changing vacuum to manual and if so can I get some info on the same.
 
to do this right you need a donor manual t/case front half and shifters.
once you have this then it is a 2 banana job.
 
vacuum switch on the tcases is only for 4hi, 4low is engaged with the 4wd shifter.
((unless bj74 has vacuum 4lo??))

your shifter might be seized. you can take of the shifter from under and grease the bushing
 
hi..cheers..
have checked and appears shifter is ok.
Put the car on stands and engaged 4 low. No movement from the front tyres.
Tried again and this time front tyres rotated.. then stopped..
have checked shifter, switches etc but cant see anything wrong
 
are you getting vacumm to the VSV from the engine or did a line come loose?
 
I understand you've allready exchanged the electrical switch on the transfer that commands the VSV when the shifter is moved to 4low.
When 4 high (dashbutton) is pressed, does it work?
If yes, then there must be some kind of intermittant connection between the X-ferswitch and the VSV.
If the 4high is not working properly, there can be a problem with the power source (bad fuse? / connection?) or the VSV itself.
Also check the vacuumhoses.
I once got screwed by a cut in the hose between pump en VSV. It was sharp and more or less closed most of the time. Sometimes leaking enough to make the system inoperative.
 
does 4hi work?

in my truck, i have to engage the 4hi first, then shift into 4lo
(this is because a sensor wire is cut?)
 
Chui ,you should have kept it all in one post .
 
I would be as a first step replacing all the VSV vaccumm hoses. WIth the age of your vehicle they may be split in places you do not expect.

then I would be checking the H4 switch - and check there is a circuit with a multi meter if after the hoses change it does not work.

I am assuming you have H4 buitton and then LO/HI lever correct?
 
sorry for the various posts. Im still getting used to this forum.
I have no H4 button.
Was damaged when I did the engine change.
I cant find a H4 - 24V switch here in kenya. thats the problem. Only 12v ones available.
Checked the hoses. cant see any leaks etc.
You can feel the vaccum, from the transfer case. doesn not seem to be any blockage.
let me try checking the hoses again and then see whats up.
thanks
 
i have a 24V H4 switch that i will give you for the cost of postage...
 
ok finally found a switch and connected the system..
the 4wd engages at the press of a button but then when you press it again to release it doesn dis engage in time.. takes long and even once did not disengage.
the guy im working with tells me that there is a minute hole in the diaphragm rubber!!!
 
chui said:
ok finally found a switch and connected the system..
the 4wd engages at the press of a button but then when you press it again to release it doesn dis engage in time.. takes long and even once did not disengage.
the guy im working with tells me that there is a minute hole in the diaphragm rubber!!!
Click to expand...

Good to see your getting somewhere. Before you check the diaphragm,make sure the hose going to the shift mechanism is also leak free.
You can also isolate the problems by swapping hoses over .
 
chui said:
ok finally found a switch and connected the system..
the 4wd engages at the press of a button but then when you press it again to release it doesn dis engage in time.. takes long and even once did not disengage.
the guy im working with tells me that there is a minute hole in the diaphragm rubber!!!
Click to expand...

Check the VSVs. The release VSV may not be working. Check that the engage VSV is shutting off. If it engages okay then it's not the diaphragm.

~John
 
Hey guys, im having the same problem.. checked the two vacuum solenoids and they are working fine, when i press the 4H button on the dash it lights up, lock the hubs up but still no 4x4. took the vacuum lines off and sucked on each one and hear the trans/case moving and when moving at 1km/h it crunches in but still no 4x4. Please help
 
Are you sure the transfercase is working properly? You can find out by checking or the propshafts are "connected". Engage 4x4, put the gear in neutral, jack the wheels at one side of the rig so they're off the ground. If now you turn one of the wheels by hand, both propshafts should turn.
If they do, only thing I can think of is the hublock(s) are not engaging properly.
 
I will explain here my story about this topic. I just had a shop rebuild my Transfer case in my 1989 JDM BJ74. I picked it up late Friday afternoon and as soon as I got the chance to try it I noticed the 4WD light does not come on in 4Low. I put the truck up on jack stands and confirmed that there is no power going to the front driveshaft. If I engage the vacuum shift 4Hi button on the dash then I do get power to the front driveshaft whether in 4Low or 4Hi.Can you guide me what can be happened?
 
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