How to Replace the Leaf Springs on a Double Axle Trailer？

When the leaf spring breaks due to a malfunction, we must replace it with a new one in time to prevent dangerous accidents during the driving of the tandem axle trailer. And before replacing the leaf spring, you need to spray anti-rust penetrant on all the nuts and bolts to be processed to make them easier to remove. The following is the method of replacing the leaf spring of a tandem trailer.

You need to do is break the lug nuts on the tires first, because if the lug nuts are super tight or a little rusty you won’t be able to loosen them as easily once the tire is off the ground.

You don’t need to take off the lug nuts completely, just get the first turn done so you know they will come off easily later.

Depending on the size and weight of the trailer, this can be quite a difficult task.

Because a trailer is generally heavy, two big jacks are needed to get one side off the ground. You need the jack to be close to the wheel and use the frame to lift.

Make sure you are using wheel chocks on the other side of the trailer so it won’t be able to move around.

If you are using two jacks be sure you lift the trailer evenly until the tires are off the ground.

Once you’ve got the trailer where you want it you can lower the weight of the trailer onto jack stands or set them up for safety.

You can now remove the first tire. It is generally recommended to remove only one tire at a time, just in case.

You can now place the jack under the axle you just removed the tire from.

Once the leaf spring is removed the axle will fall if nothing is there to catch it. That’s why you want the axle jack in place before you start removing the leaf springs.

Now it’s time to start working on all the nuts and bolts that are holding the leaf spring in place.

I started by loosening the nuts on the top center of the leaf springs. The ones that are connected to the U-bolts.

If the bolts are rusty and just won’t come off you may need to cut them off later.

Next, loosen the bolts holding the two eyes of the leaf spring into place. It’s easier to start with the center bolt which is the one connected to the shackle of the equalizer.

Once you’ve got the nuts off you may have to hit the bolts with a hammer to get them to come out.

If you lift the axle with the jack a little bit this may make it easier for the bolt to come out. It’s a good idea to get a replacement for this bolt as you may damage it when removing it or you may need to cut it off.

Once the main bolts holding the leaf spring to the trailer are removed you will notice that the only thing holding up the axle is the jack.

Be very careful to not put your hands, feet, or legs under the axle just in case it falls.

You can now finish removing the nuts holding the U-bolts. Once you’ve removed the U-bolts and U-bolt plate you can take the leaf spring off.

Your new leaf spring will have a bolt on the top and bottom in the center.

This bolt will align with the leaf spring hanger on either the top or bottom of the axle depending on how your trailer’s suspension system is made. It will also help you center the leaf spring.

Once the leaf spring is in place you can install your new U-bolts. I reused the U-bolt plate because it was of better quality than the new one.

You can use the new ones or reuse the old ones if it seems better. The only thing you should not reuse is the old U-bolts and U-bolt nuts.

Tighten the U-bolts so they are snug, you do not need to torque them to the correct poundage yet.

You can now insert the bolt through the eye of the leaf spring on the equalizer side (inside).

It’s easier to do the equalizer side first because you may need to adjust the axle position to get the holes to line up with the other side. If you are replacing the shackles you can do this now.

The bolt goes through the first shackle, then the leaf spring eye, then the second shackle. The nut will be secured to the bolt on the inside.

You don’t need to tighten the shackle bolts too snug. The trailer’s suspension system is made to move freely which means the nut should be tightened enough to stay in place but you will be able to move the shackles around.

Now it’s time to put the bolt on the other side of the leaf spring.

If you have the correct length of leaf spring it should be easy to line up the eye with the holes of the leaf spring hanger.

Once you’ve lined everything up you can insert the bolt. Make sure the nut is on the inside of the trailer.

You can tighten this more than the shackle side but you still want it to be loose enough to allow the leaf spring to move and bend.

Once you have secured the bolts to the leaf spring eyes and have the U-bolts installed around the leaf spring and axle correctly you are now ready to remove the jack holding up the axle.

Once you remove the jack the axle will be held up by the leaf spring.

Earlier you secured the nuts on the U-bolts so they were snug. It’s time to torque them to the correct poundage so the U-bolts can stretch securely around the axle and leaf spring but also allow for the proper amount of movement.

To find the correct torque poundage you will have to look up what the U-bolt manufacturer recommends.

Once everything is tightened and secured you are ready to put the tire back on. Remember to tighten the lug nuts in a cross pattern.

Tighten the lug nuts as much as possible by hand or with a small wrench. Once the lug nuts are snug you can now lower the trailer slowly and evenly until you are able to remove the jacks.

Once the tires are on the ground and the jacks are removed you can torque your trailer’s tire to the proper ft-lbs.

You should never replace just one leaf spring, they need to be replaced in pairs or all of them.

If you only replace one it may cause uneven wear and improper alignment of your trailer tires.

If you are putting on a different size of leaf spring you must replace all 4 so they match.

Once the replacement is complete, you need to check all the nuts and bolts regularly to prevent the leaf springs from falling off. If you want to learn more about leaf springs after reading the above content, you can contact us for a comprehensive solution.

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