Trailer Jacks

Trailer jack

A trailer jack is an important part of safe towing. If you need to add or replace a jack on a trailer, the following information can help you choose among the many kinds to find the right one.

Basic Functions of a Trailer Jack

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Trailer Weight Capacity and Height

Trailer jacks come in different weight capacities and lengths. Remember to consider the length of the jack in both the retracted and extended positions. When extended, the jack has to lift your coupler high enough for it to clear the hitch ball on the vehicle. And the jack has to retract far enough to clear the ground when you're traveling. The following information can help you find a jack with the proper weight capacity and length for your application:

1. Determine the Height of a Jack

Jack dimensions in retracted and extended positions

To determine if a jack will work for your trailer, you'll need to know its height, both retracted and extended. These dimensions are usually given for jacks. They're taken from the bottom of the jack (including any foot that may be present) to the mounting point. The mounting points can vary, depending on the style of jack. Standard A-frame jacks are usually measured to the bottom of the mounting flange. Pipe mount jacks are measured to the center of the mounting pipe. Jacks that have a bolt-on bracket are usually measured to the centerline of the bracket.

measuring trailer tongue weight trailer tongue weight scale

2. Trailer Tongue Weight

Trailer tongue weight (TW) is the downward pressure that the coupler places on the hitch ball. Typically, TW is 10 to 15 percent of your gross trailer weight (GTW), which is the weight of the trailer when it is fully loaded. For example, a 5,000-lb trailer has a TW of 500 lbs to 750 lbs pressing down on the ball.

trailer tongue height

3. Trailer Tongue Height

Jacks for Standard Ball/Bumper Pull Trailers

A-frame Trailer Jacks

A-frame trailer and jack topwind A-frame sidewind A-frame power A-frame

Side Mount Trailer Jacks

Side mount jack on pole tongue trailer Side mount jack

Side-mount jacks either bolt or weld to the side of the frame of a pole tongue or A-frame trailer. The pivoting design lets the jack swing up and out of the way for towing and down for jacking. Manual crank jacks come in one of two styles - cranking from the side (most common) or top. One type may work better than the other depending on the clearance around your trailer.

Three mounting styles for side mount jacks:

1. Pull-Pin Swivel Trailer Jacks

Swivel mount jack in up position pull pin swivel

2. Pipe Mount Trailer Jacks

pipe mount topwind pipe mount topwind Tube mount for pivot jack

3. Drop-Leg Trailer Jacks

sidewind drop-leg dropleg jack

Heavy duty jacks with power drive RV Landing Gear

RV Landing Gear and Heavy-Duty Jacks

Jacks to Stabilize Trailers

Fifth Wheel and Gooseneck Stabilizing Tripod Jacks

gooseneck tripod fifth wheel tripod

Light-Duty Stabilizing Jacks

light duty stabilizer

Scissor Jack Stabilizing Jacks

Scissor jack installed and in raised position scissor jacks

Pipe Mount Trailer Jacks

pipe mount topwind pipe mount topwind

Slide-out Supports

Supports for a trailer slide-out

Electric- and Manual-Adjust Stabilizer Jacks

Electric stabilizing jack for camping trailers

Leveling System

Electric stabilizing jack for camping trailers

Slide-in Camper Jacks

Slide-in truck camper jacks

Camper Step Stabilizer Jack

Camper step stabilizer jack

Trailer Jack Accessories

jack foot

Jack Stabilization Accessories

Jack Feet

Other Jack Accessories


Casters or Wheels

Wheel chocks in use EZ jack and wheel chock

Wheel Chocks

Repair Parts and Kits

replacement miter gear

Trailer Jack Gears

replacement handle

Jack Handles

weld-on mounting brackets bolt-on mounting brackets

Replacement Mounting Brackets

Written by: Raymond P.

Last updated: 7/5/18

Questions and Comments about this Article


I have a Haul-master 2 wheel jack. I think I over shot, my trailer isn’t heavy enough to turn the wheels when empty. CanI convert it to a single wheel?

Etrailer Expert
Reply from Jon G.

If you have a removable caster wheel set then you might be able to replace it with something like part # BDCP555 but I would also check to make sure that your current caster freely spins and it doesn't need any kind of lubricant.

Tom K.

I had a stabilizer fall off on a trip, should I have a plate made and welded back on or just bolt the new stabilizer back on to the frame?

Etrailer Expert
Reply from Kef G.

I would go with a new stabilizer. Making a new plate and welding it can work, but there can always be complications when make-shifting a plate.

John T.

Is it ok to fully extend the tongue jack while parked in driveway to level the camper?

Etrailer Expert
Reply from Chris R.

As long as you aren't "over" extending the jack, you can certainly use it in its fully extended position to keep the camper level while parked.

Arvind K.

How does the jack work. Any pictorial diagram to see how it works. I would like to buy the drawings for my trailer. It is not possible to import one piece.

Etrailer Expert
Reply from Chris R.

Are you looking at a particular trailer jack model? I'm not sure I would be able to obtain in-depth diagrams, as it could approach propriety information, but I can certainly try to answer any questions you have.



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