Tsadi from Rasta 4×4 in Israel provided Expeditions West with a new JemmyJack prototype to test. This unit is entirely unconventional, and it is exciting to see a completely new approach to changing a tire or axle on the trail or even on the side of the road.
Upon initial inspection, Jeremy and I were understandably skeptical of it working in the dirt, or working at all on concrete or pavement. Would it just slide? Could it lift the axle high enough? Would it be stable? The result was impressive.
The JemmyJack is constructed from 5mm steel, which is bent and formed, then all connecting flats are welded. The weld quality is good, with no visible splatter or deformation, and all welds are finish ground to a smooth surface. The entire jack is cad. plated for a quality finish and resistance to rust. The jack is essentially three main components: 1. The jack base, which is also the recess the jack arm folds into. 2. The main jack pivot arm, which is constructed from square steel tubing. 3. The jack arm extension, which allows variation of lift heights and accommodate different tire sizes. Brilliant in it’s simplicity, the jack folds into itself, and the cross pin that sets the arm height slides through an opening in the base and keeps the entire unit closed for storage.
1. Remove the cross pin clip
2. Remove Cross Pin
3. Flip lever arm out of base
4. Set Jack Arm Height to Tire Height (Note: If tire is low or flat, you will need to set it to the height of the spare, etc.)
5. Place Jack cradle up against axle tube
6. I would want to use a spotter, but if you are solo, engage 4wd (i.e., ensure the center differential is locked if equipped) and low-range if possible (we tried in high and low range), then select reverse gear and back up slowly, the leverage of the arm will lift the axle and suspend the tire off the ground.
In this case, a video is better than a thousand words! Download Video Here
This is a specialty jack, and would typically be carried in addition to a bottle jack or Hi-Lift jack. Its greatest strength is speed, and it is actually quite safe and stable if placed properly. Certainly safer than a Hi-Lift that needs to overcome suspension droop or have the axle tethered. In rocky terrain, or if the vehicle is completely immobilized, the jack would not be useful. For changing a tire on the trail or on the road, it is fantastic. The unit is also somewhat limited on tire height, with a 35″ tire being the maximum, though I do not see this as much of a disadvantage, as most overland vehicles use tires smaller than a 35. The unit should be handled with gloves (as should all jacks), as several edges are sharp, and it is somewhat heavy at 15lbs., though it packs compact, and is easy to store.
Specification: (price TBD)
Construction- 5mm steel, cad. plated
Weight- 15 lbs. (6.8kg)
Length / Width / Height – 15.5″ (39.8cm) / 5.25″ (13.3cm) / 4.25″ (10.8cm)
Rated Load (coming soon) The rear axle of a 7,000 lb EarthRoamer was lifted in the test.