Hijacking Out of a Bind: Building your own specialized floor jack

The basis of this article is the inexpensive 2-ton jack available atmany auto parts stores. I think they are made in different factories inChina, but they are all copies of one another and have only slightdifferences. However, if the box says they will go up to about 151/2inches, they will work for our purpose.

I have used and modified jacks of this type for years. In some I havecut off the wheels, added a plate, and made some changes to the handle.This jack works fine in a dirt pit area.

Now, I have modified these jacks again to do a specific job. The firsthas looks reminiscent of a helicopter. Sadly, it won't fly, but it willlift a rear-end housing.

More than once I have had to install a rear end by myself. Trying tohold and balance the housing on my regular floor jack while rolling andturning it under the car has proved to be quite a chore. On aleaf-spring car this might not be too bad, but hooking up three or foursuspension links is a different matter. This seems especially true onthe GM metric cars. In these cars, the bolts go in at odd angles andmake correct alignment difficult. I appreciate anything that makes thisjob easier.

BUILDING THE HOUSING JACK

The first thing to do is make the wide front legs with the outriggerwheels. This is necessary to keep the housing from overturning the jack.Split the front axle of the jack. Install each half in the outrigger tosupport the wheels. I have found the size and shape of the arms workwith the 9-inch Ford and 10-bolt Chevy rears that I have. There are manyvariations of brackets and castings, so measure yours and adapt theplans accordingly.

As designed, the jack holds a 9-inch Ford housing, with or without thethird-member being installed, as well as the 10-bolt Chevy. All the armsare made from 1x0.095-inch square tubing.

The yokes and the half-circle bracket are made from 1 x 3/16-inch flatsteel. Use whatever materials you happen to have in your shop and makesure that they are at least as strong as what I have used here. There isone change from the pictures on the arms. Instead of the arms angling uptoward the yokes, use a straight tube with vertical tubes up to theyokes. This simplifies construction. It is shown on the plans this way.

The half-circle yoke is attached to a threaded rod so that it canrotate. The rod can be adjusted vertically to fit and level the nose ofthe rear used. This rod goes through a long coupler nut welded to a tubecoming from the center of the arm.

This unit is now welded to the cup on the top of the jack. To do this,pull out the clip under the cup and remove the cup. Weld the cup to thearm. Do not reinstall the cup using the clip. Weld a washer in itsplace. The clip is too weak to handle the side-loads the housing can puton it. When finished, there will be enough rock in the arms to allowline-up if your car is reasonably level with the floor.

I found the jack handle to be in need of modification too. It needs tobe shortened and welded at an angle. This greatly assists in giving youmaneuvering room under the car. The handle is then welded to its socket.Be sure to pull the clips and remove the socket before welding. Thiskeeps the welding current from going through parts of the pump and jackcylinder.

The jack's valve has only a stem sticking out. Weld an extension to itabout 11/2 inches long with a washer on the end to make it easy tooperate. When you are under the car with it, the valve will be withineasy reach. Before removing the valve stem, stand the jack vertically onits front wheels so fluid won't run out. Remove any O-rings or washersfrom the stem and wrap the threads with tape. This will protect thethreads from debris when welding. Now, weld on your extension, and youshould be finished with your first jack.

BUILDING THE 3rd-Member JACK

I thought of building this jack once when I found myself under the carwith a 9-inch third-member lying on my chest. This jack is sometimes amate to the housing jack. Changing an iron third-member using this jackmakes the job almost a pleasure.

The jack used is the same inexpensive parts store jack as used for thehousing jack. The first thing I did was reverse the handle. It is weldedon top of its socket in the opposite direction. A kink that can be abend or a cut-and-weld keeps the handle close to the jack body. I foundthis position worked well under the car. The valve should be modifiedthe same way as the one on the housing jack.

Rather than go to the trouble of making a wider front track, I made somewings from 3/8-inch steel rod. These stick out about 8 inches and clearthe floor by 3/16 inch. This is enough stability that I didn't have aproblem with the weight of the third-member turning the jack over duringthe installation process.

The holder for the third-member is made from a piece of 3/4-inch pipe(about 1 inch diameter) that clamps in the U-joint socket with theU-joint bolts. The pipe is then welded to a square tube that has3/8-inch round rods welded to it in a "V" formation. This "V" forms aplace for the casting to nestle during installation. Again, there arevariations in the 9-inch castings, so your dimensions may vary from theplans. To reach the proper height, a piece of the same 3/4-inch pipe isused as a riser. One end welds to the square tube holding thethird-member while the other welds to the cup on top of the jack. Asbefore, remove the cup to weld. Weld a washer in place of the clip tomake sure that the tiny clip doesn't shear with the side-loads.

CONCLUSION

The changes to these jacks can be accomplished with a welder, a torch,and a drill. I had originally planned to use the same jack and changethe cup. After seeing the small size of the clip holding the cup inplace, I decided to weld a washer on the bottom of the cup stud. Thejacks are so cheap that I made a dedicated unit for each purpose.

Contact Sleepy at: sleepy.gomez@primedia.com