FD dash pull knob (1 Viewer)

[asu4runner]

from what I have read in some recent searched here on mud, the FD knob on the dash of my 67 fj40 is the vacuum actuation for the front diff correct? just trying to straighten out what mods the PO have done. I have Warn manual lockout hubs, that are definitely not new. wouldn't a vac operated 4wd have hubs that were always engaged? im mostly basing these assumptions off of crappy late 80s mopar 4wd's I have worked on. also, is the little lamp near the tcase shifter supposed to illuminate when the front diff is engaged? if the truck has been converted over to the warn hubs, does that mean that the vac system is no longer required? thanks in advance for answering 17 questions about a knob.

 

[4Cruisers]

My '71 FJ40 and '89 FJ62 both had vacuum operated front drive engagement and manual locking hubs. My '93 4-Runner has ADD (vacuum to lock/unlock hubs). A lot of Toyota truck/4-Runner owners switch out the ADD to manual locking hubs.

 

[Poser]

if the truck has been converted over to the warn hubs, does that mean that the vac system is no longer required?

No, you need the vac system to control the front drive actuation of the transfer case.

 

[asu4runner]

My '71 FJ40 and '89 FJ62 both had vacuum operated front drive engagement and manual locking hubs. My '93 4-Runner has ADD (vacuum to lock/unlock hubs). A lot of Toyota truck/4-Runner owners switch out the ADD to manual locking hubs.

this is what I am more familiar with, so the idea of a drive shaft engagement is foreign to me. thanks.

 

[asu4runner]

No, you need the vac system to control the front drive actuation of the transfer case.

thank you, I get it now. I was under the assumption that the engagement was inside the axle, like a collar or sleeve.

 

[Living in the Past]

thank you, I get it now. I was under the assumption that the engagement was inside the axle, like a collar or sleeve.

The ADD system is only part of how it works. When you go to 4WD the transfer case engages the front driveshaft at the same time. The rest of the time it is not engaged.


Your picture shows a PO changed your heater system to a 74+ type. That includes a valve on the firewall to control the flow of coolant to the heater core.

 

[asu4runner]

The ADD system is only part of how it works. When you go to 4WD the transfer case engages the front driveshaft at the same time. The rest of the time it is not engaged.


Your picture shows a PO changed your heater system to a 74+ type. That includes a valve on the firewall to control the flow of coolant to the heater core.

I actually found this out last night while poking around the engine bay. I notice the heater valve was pretty clean, so I started digging around online and found the conversion kits. is this a better system? just wondering why it was converted over.

 

[Living in the Past]

I actually found this out last night while poking around the engine bay. I notice the heater valve was pretty clean, so I started digging around online and found the conversion kits. is this a better system? just wondering why it was converted over.

The original system has a twist valve on the cylinder head where the coolant feeds the heater. Generally on early ones open in the fall and close in the spring. Use only the fan speeds to control the heat. It also did not have the vent at the top of the heater. 74-76 the vent in the cowl was welded shut. After that gone completely in the US market where heater was standard. Besides a different heater 67 had a bracket screwed to the bottom of the dash for vent and fan switch.