Tell me how to use 4WD (1 Viewer)

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I have an "F.D" knob which engages my front wheels. My glove box sticker (see below), as translated by mot (thanks mot), says:

"How to use the transfer
1. Under normal driving condition, keep it in the "H" position.
2. In a rough terrain, sand, or snow, engage the front drive.
The switch knob, "F.D" should be used at low speed, while going straight.
3. When towing something especially heavy put the transfer lever
in the "L" position. The front drive automatically engages.
4. On vehicles with free-wheel hubs be sure to operate "2" and "3" while in the "lock" position."

Because I'm an idiot and don't understand basic mechanical concepts, I still don't quite get it. What added benefit do I get with the "F.D" knob that others without it don't?

Help, I'm stupid.
Julie and Aaron Wedding 025.jpg
 
Front Drive

It appears that in order to get 4wd high range you need to pull FD and have the xfer case in H

for low 4wd engages automatically

the fd engages the 4wd using the vacuum system underneath your hood on the rh side


you can get later models with lever engaged 4h and 4l but I hear the vacuum system works pretty well and is kinda cool
 
Well, instead of a shift lever in your floor for transfer case shifting, yours is activated by the pull/push lever on your dash. Cable activated to the transfer case.


Wecome to I8Hmud :cool:
 
Yup! I've learned something new about these vehicles every day now for years. A cable activated vacuum actuator for high/low only??

Cool!:steer:
 
Just don't pull it out while driving at regular driving speeds you will hear a nasty noise from the Tcase.
Mine is next to my wiper switch and I have grabbed the FD knob instead of the wiper knob while driving at night OUCH
 
Wouldn't that be just a vacuum actuated front drive, just like all of the E - 9/71 trucks have? Maybe it's cable to the transfer case in that younger truck, but I think you'd have to look.

Anyway, conceptually, the FD knob engages your front driveshaft, not the wheels. The front axle drives the wheels, which may or may not be locked to the front axle: which you switch at the hubs.

If it is vacuum actuated, the advantage over a lever/direct FD engage mechanism is that because the vacuum is a gentle engagement (once it has been done a few times, lubricated up, and gets smoothed out) you can easily switch the front drive on and off at speeds of up to 45mph without grinding. Anyway, that's the way it works with my trucks.
 
Thanks for all the replies.

I think I'm starting to understand. Correct me if my skull is still too thick though.

If I didn't have the FD knob I would have to have a transfer case shifter that has H2, H4, N and L4. By having the FD knob I don't have to stop and shift the transfer case from H2 to H4, I just simply pull the knob. Essentially it's 'shift on the fly' (shift on the crawl in a cruiser).

The knob mates the driveshaft to the axles but I still need to manually lock the wheels to mate the wheels to the axles.

Sound right?
 
The knob mates the transfer case/transmission to the front driveshaft. The driveshaft is always connected to the axles via the front differential. Otherwise, yep!
 
Thanks for all the replies.

I think I'm starting to understand. Correct me if my skull is still too thick though.

If I didn't have the FD knob I would have to have a transfer case shifter that has H2, H4, N and L4. By having the FD knob I don't have to stop and shift the transfer case from H2 to H4, I just simply pull the knob. Essentially it's 'shift on the fly' (shift on the crawl in a cruiser).

The knob mates the driveshaft to the axles but I still need to manually lock the wheels to mate the wheels to the axles.

Sound right?

Right, but the FD knob only puts you in 4WD high range....you still need to pull the lever that is just below the dash all the way out (toward the rear) to engage 4WD-low range. And about midway between the all-the-way-in 4WD-H and all-the-way-out 4WD-L puts the transfer case in neutral.

HTH
Pete
 
Can you run these early cruisers in 2wd low with using the transfer shift lever and not the FD button? Thanks, ty

BTW, it seems my FD button is "engaged" when it's pushed in rather than out. ???? I was looking the the drive shaft with the shift cover off and the shaft was turning with the button in rather than pulled out. Is this possible? thanks. sorry for the hijack, ty
 
The FD button engages the transfer case the lever makes gearing selection 4H-4L when the transfer case is not engaged you are in 2H,I have never tried running in low without the TC engaged not sure if it is possible to do this not sure of the benefit if it is possible.
Try it and let us know if you drop your TC we will learn from your mistake.
 
Don't know about your 80s trucks, but it is simple to modify our early 3 speed trucks to run in 2 low. I have done so and run it without issue the few times I've felt like it was indicated.
 
My trucks are a '79 and an '83, I used to have a '76, they all have the floor lever, I always shift on the fly (when the front hubs are engaged). It is easier than trying to shift when sitting still, especially going from 4H to 2H. From 4H to 4L and back does require the truck to be stopped, or nearly so (IIRC the Owner's Manual says less than 5kph).
 
One word of caution for the winter months, I had a '70 built in '69 and the vacuum would freeze sometimes, so I would have to remember to activate the 4wd the night before a big snow storm. Ahhh the early cruiser owner days of being broke, or tooo afraid to find out what the repair bill was going to be.:doh:

Enjoy your ride
 

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