Bumper Pull Trailer Jack Maintenance and Repair
It’s bumper pull trailer jack maintenance and repair time, so here’s the step by step how-to’s.
Photo 1 – Remove the jack from the horse trailer. The easiest method of supporting the tongue of the trailer while the jack is removed, repaired and replaced is to attach it to the tow vehicle. With this particular model trailer, the nuts are welded to the underside of the frame, and bolt removal is accomplished with ease.
Photo 2 – Most jacks have a pin/clip affair attaching the handle assembly to the jack. When this pin (or in the case of this jack, bolt) is removed, the screw assembly slides out of the bottom of the tube.
Photo 3 – When the bearing and washers are removed from the top of the screw assembly, they expose their condition. While this set is only about a year old, the wear is apparent on the washers, which now have grooves worn in them from improper lubrication, and contamination by dirt and grit. The small round affair on the left is a felt washer/spacer designed to help keep grease in the bearing and the bearing centered on the screw assembly shaft. In the assembly, it fits inside the hole in the center of the bearing.
Photo 4 – This is what the bearing and washers look like after being sloshed around in repeated mineral spirits baths until the mineral spirits no longer runs brown with accumulated gunk. Notice the bearing race has deteriorated at one point and no longer has a firm grasp of all the balls comprising the bearing. These balls will be reinserted and the bearing/washer assembly will be functional for years to come with proper care and lubrication. The felt spacer was not washed.
This is the point where you must decide what needs replaced. If the bearing is not reusable, take the race and as many balls as are still intact to a local bicycle repair shop for matching size and weight. If you know the manufacturer of the jack, you can contact the manufacturer for replacement parts. If the washers are so grooved they cause the washer to contact the bearing race, they can be replaced, or reversed (ungrooved side against bearing) and reused after a thorough cleaning with steel wool.
Photo 5 – These are the drills and tap you will need (also appropriately sized wrenches). These drills are titanium coated (yellow for identification purposes). The smaller drill is a pilot drill. Drilling a pilot hole first makes the job easier. The larger drill is 7/32nds. The tap is 1/4 inch, standard thread.
Photo 6 – Here is the jack tube set up and ready for drilling. Notice the tube is supported so it is level over its length.
Photo 7 – Here the pilot hole is drilled.
Photo 8 – Here the final hole is drilled. Cutting oil was used to help ease the drilling.
Photo 9 – Here the tap is run down into the hole. I used a crescent wrench to turn the tap into the hole to create the threads for the zert.
Photo 10 – This is the point where you will need to remove any burrs and stray bits of metal from the drilling and tapping process. It’s also the right time to rinse the tube with mineral spirits and remove all the old lubricant, dirt and grit. The picture shown is the final step of this process. I have lightly filed the inside (curved file wired to a long piece of dowel) and outside of the tube (flat file) at the drill/tap site to remove burrs and have rinsed the tube with mineral spirits. Here I’m wiping the inside down with a tack cloth wrapped around a piece of doweling.
Photo 11 – This is the zert fitting installed. Zert fittings have a very small ball held to the inside of the hole by a spring. This allows the grease to be forced in, but keeps dirt and moisture out. The head of the zert fitting snaps into the opening of the grease gun, holding the grease gun applicator in place while grease is inserted.
Photo 12 – This is how the bearing/washers will be reassembled. Note the washers are two different thicknesses. The thicker of the two washers goes on the post first, then the bearing with the open side of the race up (toward the end of the post), then grease will be manually applied and finally, the thinner of the two washers will be installed. This final dry fit allows an opportunity to ensure there is sufficient room between the bearing race and the washers to provide adequate clearance.
Photo 13 – The top washer has been removed and grease has been generously applied to the bearing assembly and screw threads.
Photo 14 – Now the top washer is added and the assembly is inserted into the tube.
Photo 15 – Here’s the final assembly with handle reattached. What isn’t apparent from the picture is the washer that was added to the top of the shaft where it protrudes from the tube. This new washer will help keep dirt out and the grease in. When the jack is reinstalled on the trailer, the zert fitting is put toward the back of the trailer to minimize the chance of it being damaged when the trailer is hitched/unhitched from the tow vehicle. For full protection from the elements, a liter pop bottle with the top removed will be placed over the top of the jack.