Converting an FJ62’s 4WD Vacuum Shift from Electric to Manual
By Spook50
By Spook50
After 18 years and 217K miles, the electric solenoids that control my transfer case’s ability to shift into (and out of) 4WD had finally failed. Any electrical part will do this eventually, so why pay $300-$400 for a new part that will fail again (albeit most likely not for several more years)?
To understand what I’m talking about, let me first explain how an FJ62’s transfer case works. To shift between high (1:1 ratio) and low (2:276 ratio) gears, the case is shifted by a stick. However, instead of using that same stick or even a 2nd stick to shift between 2WD and 4WD, the case relies on a vacuum actuated diaphragm. The position of this diaphragm dictates whether the case is in 2WD or 4WD, regardless of what gear it’s in. The vacuum to this diaphragm is controlled by two solenoids mounted on the firewall, just inboard of the windshield wiper motor.
There you are you little buggers...
When the top solenoid is active (linking the manifold vacuum source to the appropriate vacuum hose connected to the transfer case), vacuum forces the diaphragm to shift the transfer case into 4WD, and the bottom, when active, does the same thing, causing it to shift into 2WD. The electric drive selection allows for 4WD high range to be activated with the push of a button. This setup is convenient, but inherently flawed. There is also a switch installed on the transfer case that will automatically activate the 4WD solenoid when the case is shifted into low range. The stock configuration allows for three gearing options, excluding neutral; 2WD high range, 4WD high range, and 4WD low range. Due to the automatic drive selection, 2WD low range is unavailable.
As with any electrical part, these solenoids will fail eventually. With the high price of a replacement part, a common practice is to find an idle up solenoid from older Toyota Camrys and Celicas. The parts are nearly identical, with the only difference being the style of electrical plug. These solenoids are approximately $30 new from a Toyota dealership. Much more favorable than a new pair of transfer solenoids that cost upwards of ten times that amount. When my original solenoids failed I debated on converting to the other solenoids, but with the parts being electrical, I wanted something that would go a lot longer before failing.
For over a year I looked into my other available options. I could spend $600 for a used transfer case off an FJ60, which uses a stick for both 2WD/4WD and high/low gears. With an easy modification to the linkage (or with the fabrication of a twin stick setup), this would give me the wanted option of low range 2WD. That was more work and money than I want to invest at this point. I could take the opportunity to split my case and rebuild it, while installing the nose cone from an FJ60’s case to gain the ability to manually shift between 2WD and 4WD, but again, that would cost the price and work of rebuilding plus the necessary parts from an FJ60’s case. Lastly, I could install a manually actuated vacuum control valve in place of my vacuum solenoids. I decided on this method, as a manually actuated valve would easily last the life of the truck itself.
The next problem was sourcing one that would fit my needs. I called around to many local hose and hydraulic shops and finally found one that caters specifically to industrial companies. I had to finagle a bit to get them to order the part, but the one I found was perfect for my application. The valve is a 5-way Norgren pneumatic valve, P/N X3044322. The ports are 1/8 NPT pipe thread, so I bought three 1/8 NPT with 1/8” barbed nipples (one of which is a right angle fitting for hose routing issues), and two 1/8 NPT brass air filters. Since the supply shop was able to get these as well, I just ordered everything together.
The valve as it is shipped. Port 1 is for the vacuum source, 2 and 4 go to the hard lines leading to the transfer case, and 3 and 5 are vent ports.
Since I have no need to pull the fittings off the valve, ever, I just raw dogged the installation (ie: no Teflon tape). Brass is “self sealing” for lack of a better way to put it, which makes it great for vacuum systems and pressurized gasses. In the next pic you’ll notice that ports 4 and 5 on the valve have the brass filters installed. This may not be entirely necessary, but I decided to err on the safe side, since when one vacuum line (2 or 4) is linked to the source (5), the other is vented to open air. This action allows the diaphragm in the transfer case to shift freely when you select a port on the valve. For example: with the switch on one position, the source port (1) will be connected to an output port (let’s say 2). Also in this position, port 4 will be vented via port 5. In the other position, 1 will be connected to 4 and 2 will be vented via 3.
All the fittings installed. The valve is now ready to be installed in the truck and have the lines plumbed.
For plumbing the vacuum lines, I bought some 1/8” ID vacuum hose and fed the vacuum source from the intake manifold (you can tell which vacuum line is for what just by looking at how they’re routed on the firewall. Just trace them from the solenoids) to port 1 (the right angle fitting) on the valve. Ports 2 and 4 were connected to the vertical hard lines that lead down to the transfer case. It doesn’t matter which of the two hard lines ports 2 and 4 are connected to. Just make sure you know which position is for 4WD and which is for 2WD when you have it all set up. For this reason I made sure to keep the functionality of my 4WD indicator light.
To get the hoses through the firewall without drilling, there’s a large rubber grommet just outboard of where the hard A/C lines pass through the firewall. It stretches easily so I punched a small hole in it next to where the wiring bundle passes through it and fed all three vacuum lines through. Make sure you keep track of which hose is for the vacuum source though. That’s the important one!
Here you can see my new hose routing and the now unused (and dangling) solenoid connectors. I’ve since cut the wire as far back into the harness as I could, since I’ll never need it again. The half-assed wiring in the pic is from my aftermarket ignition, which has since been cleaned up.
The hoses all hooked up to the valve (with the toggle lever set to the 2WD position in my case). You’ll have to jockey it into place to get the fittings and lines through that hole in the dash. Now whenever I pull the dash I just undo the nut on the toggle and remove the plate that the valve is mounted to.
The valve all installed and ready to go. The labeling is a laser etched black metallic decal that was cut to fit over the blank plates. I did up the designs in Adobe Illustrator and took them to a sign maker in Spokane Valley. As you can tell, I used the two blank plates just above my ashtray.
Works flawlessly. I blacked out the lens for the factory 4WD light and rerouted the wiring to a red 12V light I picked up at Radioshack, just so I could have an indicator near the switch. It’s very easy to see even in direct sunlight when I have 4WD engaged.
It’s been almost three years now since I did this mod and it still works perfectly. The install went so well that most people who ride in my truck and aren’t familiar with 62s think this is the stock setup from Toyota. I would not be surprised if this valve lasts the life of the truck. Finally, just for s***s and grins, here is a pic of my complete dash, with a little more laser etching just to add to the styling…
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