I am putting the FT4WD box back together and I have found it is incredibly hard to operate the diff lock lever. It takes about 50Nm to engage it while turning the imput shaft. And 40Nm to disengage using the torque wrench. Is this correct? I seem to remember being able to do it by hand with the screw driver when it was together. Will the vacuum actuator be able to operate this? Seems a bit heavy/wrong.

 

EDIT: See my below post

I can't move mine by hand. and it works fine with the vacuum actuator....

That's what I wanted to hear Cheers,

Are you in low range Phiz?

Low or high, it still is hard to shift..

 

Shifting the low range gear is easy though.

New problem... I am trying to figure how to get the vacuum actuator to fit on the gearbox with all the levers and stuff for the diff locker.

I got this gearbox without the original levers and things, was told the PT S/R gearbox lever would work which I have but I need some pictures to show me how the original fits on. So I can make up a bracket and stuff to make what I have work. So any pictures of the diff locker lever and that area would be awesome! Cheers,

Think about the forces involved. This is shooting from the hip.

 

If you have vaccum on one side of a diaphram then atmospheric pressure is on the other side multiply this pressure by the area of the diaphram and you have force. Soooooo

 

14.7psi * Pi r^2

 

where r is the radius of the diaphram roughly 2" (from memory)

and Pi is 3.14

 

You get 180 lbs.

 

So next time you want to shift you car into 4wd just stand on the lever that is assuming you wieght 180 lbs. Just realized that you are talking about the diff locker I think those diaphrams are smaller so these numbers might not be correct.

 

Lets look at the torque. I am estimating the lever is 3 inches long so max torque produced by vaccum silinoid is

f*d=Torque

f=180lbs

d=3"

T=45 ft*lbs

 

Torque in N-m= 61 N-m (so the silinoid theoreticaly produces more torque than you measured)

 

Sorry for the long winded post and I didn't even answer your question, all my manuals are boxed up. sorry

Thanks Subi81, I never thought about doing the math on it. I have a lever setup now, but I need it a little longer, it is only using 6mm of movement out of the 16mm available from the solenoid. My new setup which I will complete when I can get my brother to weld this lever up will use 12mm of the movement and I am pretty sure it is more then the original. I hopw this all works... Then it's to wiring a switch on to it and placing it somewhere on my dash...

 

Cheers for the help guys!