Rubicon Express Universal Hand Throttle

By James Hasler

  

For those of you who drive a manual tranny equipped truck off-road, you know that it can be a little tricky to drive through a boulder field without bucking. The bumps make it difficult to hold the throttle steady. Usually, I go in a low enough gear that I don't need to use the throttle at all but sometimes that can be painfully slow or not possible for fear of stalling. Well, Rubicon Express has the answer with their Universal Hand Throttle.

With this inexpensive product, you can set the throttle at a particular RPM and just go. It's also great when starting on a steep hill...especially in a vehicle like a YJ that doesn't have a hand brake. 

The Universal Hand Throttle comes with everything you need to hook up the hand throttle to most vehicles. This includes an indexed shifter (such as a gear shifter from a bicycle), plenty of cable, zip ties, installation instructions and a variety of miscellaneous parts to hook the cable to your particular throttle body.

Andrew and I both bought one of these kits and the installation on a TJ is exactly the same as on a YJ. These pictures, however, are from my YJ with the 4.0 I-6 engine. I would have shown installation pictures from Andrew's TJ, but his engine is hard to find in the engine bay...

The first step is to mount the shifter. You can mount the shifter anywhere you want as long as you can get the cable to reach the throttle body, but it really is nice to have it on your shifter. As shown below, I mounted the shifter with the lever on the right so I could operate it with my thumb. However, Andrew installed it the other way around so that he could operate it with his fingers. Whatever floats your boat. Just put the supplied rubber bushing over the gear shift and attach the shifter over the bushing and tighten it down with the supplied hardware.

The next step involves routing the cable. I first removed the outer boot off of the shifter. With the outer boot off, I poked a hole in the inner boot so that I could route the cable out of the body tub. This seemed a lot easier than drilling a hole through the body and the rubber boot would not chafe the cable housing. I then used a screwdriver to pry the outer boot away from the gear shifter so that I could push the cable housing between them. This is the cleanest way to do it. I then pushed the cable housing through the hole in the inner boot that I had just made.

Next, go under the vehicle and grab the cable housing. I pulled it through a bit at a time until I had enough to push up through the engine compartment. I then proceeded to push the rest of the cable through the boot except for enough to fit in the recessed space on the bottom of the shifter.

The cable itself has "stops" attached to it on both ends. I clipped one of them off and fed the cable through the shifter lever and into the cable housing until the "stop" was sitting in it's own recess.

Once this is done, you can attach the other end to the throttle body.

On a TJ or YJ, the stock throttle body already has two places in which to attach throttle cable and there's even a bracket to hold the other end of the cable housing. This makes it very easy. There's even an extra clip on the valve cover to hold the cable housing straight.

The only issue I had was that the bracket to hold the factory throttle cable uses a square plug to keep it from moving. The extra hole is also square. One very clean way to do this would be to buy one of these square holders for use with the hand throttle. However, the kit comes with two brackets that are large enough to not pass through the square hole, but small enough to hold the cable in place. So, using the supplied bolt with a hole drilled through it, the nut and the two washers, you can "sandwich" the square hole with the brackets. This works very well. The bolt head also has a recess in it where the other end of the cable housing goes, so make sure you route the cable through the hole in the bolt before you tighten down the nut.

Now that the cable housing is positioned correctly and attached, I snapped it into the holder on the valve cover and zip tied the cable in order to keep it away from the exhaust. I just zip tied it to the other wires that were next to the tranny.

Finally, you can feed the wire around the extra throttle body attachment and use the supplied wire crimp to complete the job. Just cut off the excess cable and you're done.

As you can see, there is a "helper" spring on the throttle body. At least on Andrew's TJ, there is a spring here from the factory. This helps keep the throttle body closed. On my YJ, after I installed the hand throttle, the additional pressure of the hand throttle overwhelmed the throttle body spring. So, I bought a spring an attached it as it was on a TJ. This was sufficient to keep the throttle body closed.

It's definitely been a great addition to my YJ.

Update:

Well, as you can see in the above picture, it is conceivable that the cable could fall off. Well, digging through the bag of parts that Rubicon Express supplied, there is a washer and clip that fits perfectly over the end of the tab that holds the cable hook. Attaching these two pieces eliminates the chance of the cable end from falling off.