Rooftop Hi-Lift Mount

Original Project Date: July 2006

Project Summary: I mount a Hi-lift farm jack on the roof rack cross bars on my H2.

A Hi-lift farm jack is a useful tool to have with you when you go off road. The factory jack that comes with your vehicle to help you change the tire is really designed to lift the vehicle on level ground just enough to raise the tires off the ground. However, in an off road situation uneven ground may necessitate lifting the vehicle much more than the several inches to change a tire.

This is what a hi-lift jack looks like.

For off-road use you typically will use a 48″ or 60″ model which, because it’s made of steel is quite heavy (30-40 lbs) and unwieldy…48-60 inches long. That’s long enough that it requires a fair amount of space to store it.

In a HUMMER H2, there are plenty of places to store a 48″ model inside the vehicle. It will fit anywhere in the rear cargo compartment. But it will also fit under the second row passenger seats. But if you have other stuff you’d like to put in those spots or if, like me, you rather frequently fold down the second row seats to carry large items in the back, the jack becomes a nuisance that has to be moved out of the way a lot.

So, what a lot of people tend to do with these jacks is mount them outside their vehicles. Do a google image search for hi-lift and you’ll see that at least 1/3 of the matches are pictures showing how people have mounted the jacks in various places.

Given this and searches at elcovaforums (A hummer discussion forum site), I found that on the HUMMER H2 people have mounted them in all the following places:

  • On their after market roof racks
  • On the front or rear bumbers
  • On their brush guard
  • On the backside of their rear, swing-arm spare tire carriers

I don’t have a roof rack…just the factory cross bars. My spare tire carrier is not the OE model that HUMMER started including on later model years. It’s a Husky Liner’s model that, unfortunately, positions the post that holds the spare wheel/tire too close to the rear lift gate to fit a hi-lift in between it and the truck.
The rear bumper won’t work because that’s where the spare tire carrier is mounted.
Furthermore, my wife insists that mounting the hi-lift on the front bumper or the brush guard is just too “redneck.”

That pretty much leaves me with somewhere on the roof. So that’s what I’ve done. I positioned the cross bars on the roof to be close enough to anchor the hi-lift at each end.

Hardware parts

I started with the following parts:

  • (2) 3/8″-16 x 3.5″ long carriage bolts fully threaded
  • (4) 3/8″ washers
  • (2) 2 3/8″-16 stop nuts
  • (2) 3/8″-16 nylon lock nuts
  • (2) 3/8″-16 wingnuts
  • (2) rubber stoppers 1 5/8″ tapering to 1 3/8″, about an inch thick

Try to find the hardware in stainless steel. It will stand up to weather better in the long run than something like zinc alloy.

I drilled the centers out of each stopper to accommodate the bolts.

Drill holes in stoppers.

Then on the fat side, I widened the holes with a knife large enough to allow the stop nuts to countersink flush in the stopper.

Countersink stop nuts in stoppers

I planned to put a small hole in the end of each bolt so I could put small locks on as a minor deterrent to stealing the jack. I clamped the bolt to the corner of a storage shelf to imobilize it as I don’t have a good table mounted vise. To make it easier to drill the holes, I flattened a spot about and inch from the end with a square file.

Flatten spot to make drilling hole easier

Then I used a center punch to start the hole and a 1/8″ drill bit to drill it by hand (make the hole large enough to accept whatever lock you plan to use).

Hole drilled

Next I removed the end cap on the roof rack cross bars. This is what it looks like:

Cross bar end caps removed

Then I slid the carriage bolts in, and hand tightened it with a washer and stop nut.

How carriage bolt fits in the cross bar.

I slid it in from the end about 10 inches and tightened it securely there.

Carriage bolt secured in final location.

Notice the rubber strip that I had to pull up. Rather than remove this, you can either poke the bolt through it or cut the strip to go around the washer. I chose the latter so that the nut/washer that secures the bolt makes solid contact with the plastic of the cross bar rather than just quishing the rubber strip.

Trimmed rubber strip around washer/bolt.

Next, slide the stoppers over the bolt then tighten the nylon lock nut over the top. In this picture, I put the nut on upside down because otherwise it sticks too far through the hi-lift frame holes and makes tightening the wingnuts on top difficult.
Also, since taking this picture, I put a washer under the lock nut to distribute the weight of the jack across the top of the stopper.

Stopper secured on bolt

Next, repeat the above process for the bolt for the other end of the jack on the other cross bar. Then slide the hi-lift over the bolts making sure it sits firmly on the top of the washer with the lock nuts inside the holes in the frame of the hi-lift. Then secure it with a washer and wingnut on each bolt.

Jack on and wing nut holding it in place

Since taking this picture, I placed a rubber washer under each nut under the wing nut to help prevent the wing nuts from loosening from vibrations.

Finally, here’s a picture of the finished project. I temporarily inserted some heavy wire through the lock holes since I didn’t have locks at the time I took the picture and I wanted something to prevent the wing nuts from accidentally backing all the way off the bolts.

View of jack on cross bars.

What does this do for my vertical clearance? Well, it makes the H2 about 7′ 3″ tall. Fortunately, my garage has an 8-foot door. Also, fortunately, I don’t currently live where I need to regularly use parking garages. Unfortunately, when I do go somewhere (like Minneapolis airport) I don’t have clearance to fit in them and will have to us an outdoor park-and-ride or remove the jack temporarily.

I am very happy with the space I’ve reclaimed inside the vehicle. Plus it’s very inconspicuous up there. In the past 5-6 weeks, not one person has said anything about it, including my wife.


If you want to always carry your hi-lift with you on your H2 but don’t have a nice Gobi rack with the special-purpose hi-lift jack mount, you don’t want to mount the jack on your front or rear ends, and you have enough vertical clearance, this is an easy way to mount the jack on the roof for just a few dollars in hardware and an hour of easy mechanical labor.

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