New 4wd vacuum motor is in...will it switch back to 2WD automatically??

[bighouse]

I just finished installing a 'new' vacuum motor/diff cover on my 83 Wag after figuring out Ive been in 4WD for a year...

When I start her up. will it automatically switch back to 2WD since the switch (on the dash) is in 2wd??? Is there a trick to this??

[joe]

I'm not sure I understand the question here so bare with me. But it's gonna start up in whatever mode you shut it down in(unless you move the switch).
If it's in 2WD when you shut the engine off...it'll be in 2WD when you start the engine. The system doesn't hold a vacuum to keep it in or out of 4WD. Vacuum is only used to do the shifting. Once it's shifted into 4WD (or 2WD) it stays that way forever(theoretically) till you apply more vacuum to the other port via the switch to shift it back into 2WD(or 4WD).
That's why there are two vacuum ports on the motors...one for engage and one for disengage. Once it's in either 2WD or 4WD you can (theoretically again) throw your vac system away if you never plan to shift it again.

[bighouse]

Hmmmm...here's the situation...its in 4WD, the selector switch is in 2WD, and I just replaced the bad vacuum motor/hoses...baseds on your post, it sounds like I should switch the selector into 4wd before I start it, start it, then switch the selector to 2WD to finally get it out of 4WD + in sync with the selector!@?

[Kimbrough]

Shoot just install your switch in 4wd mode, turn it on and see if it'll switch to 2wd...
Good luck! smile.gif

[Woody Mammoth]

On a side note, if the FSJ is in PARK, by switching 2WD to 4WD or vise versa, NP229 may or may not kick into mode. I have to work the shifter to R or D to get it kick in.

Similarly, while mine is on the move, because I switch to 4WD from 2WD, it does not kick in immediately, until speed changes.

It is true what -joe mentioned. There is no default start up transfer case mode. Whatever you have, you will have, until you get the vacuum to switch it to another.

[Oracle]

IF you made sure you got the fork in the right place when you replaced that cover,you should be able to apply vacuum with a vacum pump and drag the thing over. You may have to fool with going to neutral, into drive, reverse ,park etc. Mine likes you to throw the lever, at a standstill, then apply the brake, move to neutral, then to drive and it will move, but I get the feeling its all about getting the teeth lined up.

[irbob]

Sounds like you may have your hoses crossed. The modes don't have anything to do with the shut down and start up of the engine. Of course it needs to be running for the switch to work but thats about it.

[bighouse]

well, i drove er around...its just too hard to tell whether its switching or not. I guess that could mean its not switching at all, too!

Is there some sure fire way of knowing whether youre in 2 or 4wd while you are driving or do I have to put er on jackstands??

[Coley]

Toby,
If it's hooked up right it will switch automatically to whatever the switch says.

On your t-case, do you have a socket in the bottom to recieve a two prong plug (4wd light wire), or is this the rig you pulled the wire from that you sent to me awhile back-the one that had a plug on the top of the t-case?

[andy d]

once again, the easiest way to prove if the rig is in 4wd, is to get the rig barely rolling in gear. pull up on the range selector. if it is in 4 wheel,it will shift into low range.if not, the shifter wont budge. IT WILL NOT SHIFT INTO LOW RANGE IF THE AXLE IS NOT ENGAGED

[83 WagDriver]

I have a question that might be related
How does one align the mode and range rods so that they are aligned together. Do i force it with vice grips??I'm talking about where they meet at the transfer case.

[Coley]

Originally posted by andy d:
once again, the easiest way to prove if the rig is in 4wd, is to get the rig barely rolling in gear. pull up on the range selector. if it is in 4 wheel,it will shift into low range.if not, the shifter wont budge. IT WILL NOT SHIFT INTO LOW RANGE IF THE AXLE IS NOT ENGAGEDOh, yeah..forgot about the low range...duh :rolleyes:
Best surefire way to tell.

"Try the simple stuff first", right andy? ;)

[ July 03, 2002, 07:28 AM: Message edited by: Coley ]

[joe]

Originally posted by 83 WagDriver:
How does one align the mode and range rods.I'll email you a .jpg

[Oso]

So, if I am to understand this system right. The transfer case lever engages/disengages the front wheel drive. The vacuum motor engages/disengages the front hubs. And you cannot put the transfer case in low if front hubs not are engaged?

How can the transfer case sense that the vacuum motor hasn't done it's job?

Can the vacuum motor be engaged on the fly?

Can the 4hi be engaged on the fly?

When you disengage the vacuum motor, do you have to back 15 feet so it can disengage like auto hubs or some sort of similar ritual?

What is the sequence of events to put in 4wd and to take it out?

Bear with me please. I am used to a full sized Bronco with auto hubs. Shift the lever and go like crazy. So I am not too awfully familiar with this system. Thanks

[Wagoneer622]

Bighouse,
Here is a good way to tell if your front axle is engadged or not. have somebody put the truck in drive at the same time with the hood open look at the front driveshaft and see if it is turning, that's if you are in 2WD on the transfer case. Another good way to tell is to jack the front of the truck up in the air(of course not running) and spin the tires and if the front driveshaft turns the front axle is engadged, I hope it is engadged if you are in 4WD or your VC will be toast. Good luck. I'm throwing the poles on the rod rack on the front of the truck and going to the beach.

Chris
83 Wagoneer Ltd.(360/727/229)

[joe]

Oso, the vacuum switch on the dash switches the x-case into 2WD or 4WD via vacuum. At the same time vacuum connects the front axle(83/84 only). The front axle and the x-case have a vacuum motor on them. The mechanical floor lever on the x-case just controls HI/LO range. And no you can not put it in LO when in 2WD. It just won't go because something internal is in the way in 2WD but not when in 4WD.
Yours doesn't have an auto or otherwise hubs system. One front axle is a splined two piece and a vacuum actuated internally splined collar slides over the two pieces to connect them.
On an 83/84 you need to be at a dead stop to switch between 2WD/4WD(hence the two handed operation to pull the lock pin with one hand and move the shift switch w/the other). Otherwise expensive crunchy noises come from the front axle where the collar is trying to engage a spinning splined shaft :( Once it's shifted you may have to roll a bit for everything to line up and engage though.
The later 85 and up rigs w/229 don't have a vacuum disconnected front axle, only in 83 and 84. The later ones don't have the lock pin on the switch either and will shift-on-the-fly.