Top to bottom dolly leg maintenanceAsk any rep from Holland or Jost, What is the one thing people do not do when performing dolly leg maintenance?and they will tell you the same thing. Maintenance techs to not properly grease landing gear. I believe it is mostly because no one has trained them properly. It's landing gear right. What's not to know? There are between 2 and 5 zerk fittings that you put your grease gun on and pump a few pumps into each location. Done! On to the next task. There was grease put into the legs, it just didn't reach it's intended target. Read the dolly leg maintenance section for most any dolly leg manufacturer. The first step is always...perform maintenance on your leg with the trailer properly coupled to the tractor. We used king ping stands in our shop. The second step is to fully retract the landing gear. This is the step no one knows about. Then you have to slightly lower the legs. Usually 3 turns for Holland and 7 turns for Jost. This places the lift screw nut in the proper place to receive grease. After injecting the proper amount of grease, usually 4oz, run the landing gear up and down several times to distribute the grease along the lift screw. Then inject grease into the remaining zerk fittings to lubricate the bevel gears and gear box. This is how you perform proper maintenance on your dolly legs. If you are already having issues operating your landing gear, there are a few things you can do before you replace that set of legs. Common IssuesThree of the most common issues with trailer landing gears Lack of GreaseIf you have not been as diligent as you should have been on your dolly leg maintenance, your legs may be very difficult to operate. You will need to disconnect the cross shaft. Operate each leg to determine which leg is binding. If the legs are difficult but will retract and extend:
If the leg is completely seized you have one chance left to revive the leg.
Broken Cross shaftIf one leg will operate but not the other, you may have a broken link between the legs. While this is not considered normal dolly leg maintenance, sometimes it does happen because of a lack of maintenance. Often this repair may be as simple as replacing the cross shaft or even the cross shaft bolt. If you have a one piece cross shaft, there should be a nylock nut and bolt on the back side of each leg. Check to make sure they are both in place. If you have a three piece cross shaft, you have up to four nuts and bolts. Be sure to check them all. Replace the broken nut and bolt with the appropriate nut and bolt. Be sure to use a nylock nut. Do not fully tighten the nut as the cross shaft should be allowed to move side to side between the legs. Landing gear leg timingDolly leg maintenance will also include timing the landing gear legs every now and then. Improperly timed legs can cause the legs to bind. Another danger exists because the trailer will sit unevenly causing the weight of a load to lean to one side. This can cause landing gear to collapse. It is an easy fix though. Find a level place to park. Measure from the ground to the bottom of each leg to get a starting point. Disconnect the cross shaft between the legs. Turn the lowest leg until it is an equal distance off the ground to the other leg. Reconnect the cross shaft and check the movement of the legs. Remember to not full tighten the cross shaft bolts. They should allow the cross shaft to have side to side movement. I always use new ny-lock nuts also as they are really meant for one time use. The landing gear should be smooth and both legs should be equally timed. Dolly legs are designed to last the life of the trailer if properly maintained. A set of landing gear can run between $200 and $350 per leg. Installation should be around 4 hours per leg. You can buy a lot of grease for $1200. With proper dolly leg maintenance they will be there when you need them. return from dolly leg maintenance to tractor trailer maintenance
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