Detailed instructions with helpful pictures on how to replace a broken RV leaf spring. A broken leaf spring on your RV can put a quick holt on anybody’s travel plans. Replacing a broken leaf spring on your RV is not as difficult as I once thought. All you need are the right tools and a little information. I do not have any previous experience fixing suspension on a vehicle or trailer.
We travel full time in our 20 year old 32 foot 5th wheel. We were traveling through Pecos Texas on New Years day, Saturday, and stopped at a railroad crossing to let a cargo train pass. I noticed a bit of smoke/steam escaping from the driver’s side hood by the windshield. Yikes!!!! After the train went by and the guards went up, we drove on looking desperately for a place to safely pull over.
We were funneled into one tiny lane because of road construction, leaving no room to pull over. Moments later, I noticed, “no trailer connected” was on the instrument panel instead of the speed. I could see in the mirrors the marker lights on the 5th wheel were on. Luckily we were in a flat area where the truck could handle stopping our 5th wheel without any problems. The orange cones finally led us back to an open two lane highway with a “levelish” shoulder. I jumped at the opportunity to pull over to inspect our problems.
I popped the hood and smoke billowed out of the engine compartment accompanied by a nauseating sizzle sound. We were leaking coolant from the back of our Ram’s Cummins Diesel engine… quickly. Then, I unplugged the 5th wheel’s tow power cable from the truck and plugged it back in, still no trailer connection.
I then checked the brake wires by the wheels of the 5th wheel, that’s when I noticed, our passenger side rear axle had a broken RV leaf spring. Not only that, but the frame of the 5th wheel was sitting on the axle with the brake wires pinched between the axle and the frame, breaking the wires inside the wire’s casing. That tire was also hard against the top of the wheel well.
So, the passenger side tires were sitting on dirt just next to the edge of highway 285’s blacktop. Our driver’s side was maybe two feet from lane two of the highway. Unfortunately, very few of the trucks that passed by would move to lane one of the highway, that had the opportunity too. That made me very nervous and concerned for my family’s safety.
With that being said, I needed to get us in shape to move the 5th wheel much further away from the highway, fast. I used our 6 ton bottle jack I keep in the truck to lift the 5th wheel’s frame off of the axle. Then ripped a 2 inch piece of 2×4 I had in the bed of the truck. About ten zip ties held the piece of 2×4 to the top of the axle under the frame. I lowered the frame of the 5th wheel onto the 2×4 and our tire was free to spin without rubbing on the wheel well of the 5th wheel.
I topped off the coolant reservoir in the truck and backed the 5th wheel down a small decline off of the shoulder into level dirt. The truck was losing coolant fast while running so we decided to get a hotel room in Pecos until we could get the truck fixed, with the 5th wheel parked on the side of highway 285 until then, king pin locked. I took this time to spray all bolts that needed to be removed for the repair with Blaster Penetrating Catalyst.
After the holiday weekend, we had a difficult time finding a mechanic open and one that would work on a diesel that was not a big rig. We eventually found an amazing mechanic (Pecos River Diesel and Gas Mechanic) that quickly diagnosed our problem, ordered the part, and fixed our truck by that night.
I found a truck and trailer parts center that had the four-leaf leaf spring we needed. Once the leaf spring was in hand, reservations at TRA Park RV Park were made for the rest of that week.
I swung by the 5th wheel, sprayed the bolt threads with Blaster a second time, hitched the truck to the 5th wheel, replaced the damaged 2×4 and zip ties, and slowly pulled the 5th wheel 15 miles back into Pecos, Texas to our beautiful RV spot.
I had read a ton of information and watched a handful of videos on leaf spring replacement. I had a couple nights with nothing better to do.
When lifting one side of the the 5th wheel or travel trailer, keep the trailer connected to the tow vehicle. This allows the front end of the trailer to pivot in the hitch and still be stable.
The tires opposite the broken leaf spring are chocked in addition to the tire in front of the leaf spring to be worked on. At this point, the 5th wheel is safe to jack up on one side to work on. I chose to leave the wheel on the axle during the repair for extra security.
I had two 6 ton bottle jacks and plenty of wood blocks to place under the jacks if needed. Also, one 6 ton jack stand to place under the frame of the 5th wheel closest to the axle of the broken leaf spring.
Before moving into the 5th wheel full time, I bought a 301 piece mechanic’s tool set from Harbor Freight. I LOVE this tool set. It is not the very best quality but I have always had the right size socket, 1/4 inch, 3/8 inch, and 1/2 inch plus the wrenches and accessories. It is recommended to use the breaker bar for difficult bolts as to not damage one of the socket wrenches.
I also use a short piece of pipe, about 14 inches long, I use for extra leverage when loosening stubborn nuts and bolts. Mine is from an old fence pole I removed from my old property.
Remember, we sprayed the threads of the bolt with Blaster Penetrating Catalyst twice prior to unscrewing the nuts from the leaf spring bolts. This will make a twenty year old rusty nut much easier to unscrew from each bolt.
Put a large adjustable wrench on the bolt head going through the broken leaf spring eyelet of the free swinging leaf first. Use the correct size short socket 1/2 or 3/8 inch and a breaker bar to break the nut free. If you need it, use a short piece of pipe for extra leverage. Then switch the socket to a socket wrench to finish unscrewing the nut from the bolt.
The Suspension Bolts are splined. This is raised lines on the head side of the bolt to lock it in place. To knock the splined end out of the spring hanger, adjust the nut so the head of the nut is flush with the end of the bolt. Hit it with a mini sledge hammer to push the splined bolt free.
Before jacking up the trailer, break the rest of the nuts free from all leaf spring mounting bolts. This will include both bolt on the shackle strap, one going through the equalizer and one through the other leaf spring eyelet. Then break the nuts free on both U bolts holding the axle to the leaf spring. This job needed the correct size socket, breaker bar, adjustable wrench, a wood block and a 14″ piece of pipe for leverage.
For a frozen nut and bolt, I would use either the trailer frame or a wood block for the adjustable wrench to pry on. That way I can use both hands to pull the breaker bar instead of one hand to push the adjustable wrench and the other hand to pull the breaker bar.
Place enough wood under the jack to get it close to the frame of the RV with the jack on a stable platform. I have four 8″ x 8″ cuts of 2 x 8 sandwiched between 8 x 8 x 1/4″ plywood that that were very useful.
Jack up the side of the RV with the broken leaf spring. You want to get the RV an inch or two higher than the opposing side sitting on its leaf springs. This will give you room to maneuver parts and tools while removing the broken leaf spring.
Place the six ton jack stand under the frame closest to the axle with the broken leaf spring. This is for your safety just in case the jack fails or slips out from under the frame.
Use a socket wrench to unscrew the nuts from the U bolts holding the axle to the leaf spring. I unscrewed the nut for the shock about a half inch down the threads to allow me to move the U bolt plate. Use a deep socket, socket wrench, and an adjustable pipe wrench pliers to hold the shock.
Then unscrew the two nuts from the bolts going through the eyelet of the leaf spring, shackle straps, and equalizer. Remove the bolts from the eyelet of the leaf spring, the equalizer, and shackle straps. You are now free to maneuver the rest of the broken leaf spring out.
The hardware looked fine to me after I cleaned it so I saved it to be reused until I could upgrade all hardware.
Grease a suspension bolt, slide a shackle strap on the bolt, slide the greased bolt through the equalizer, slide the other shackle strap on the end of the bolt, and finished off with the lock nut. Hand tighten the lock nut.
Grease the other suspension bolt. Place one eyelet of the new leaf spring between the shackle straps lined up with the bolt holes of the shackle straps. Slide the greased suspension bolt through the shackle straps and eyelet of the leaf spring. Hand tighten a lock nut onto the end of the suspension bolt.
Make sure your leaf spring is bowed in the same direction as the rest of your leaf springs.
Maneuver the leaf spring up under the axle. Align the center bolt of the leaf spring with the center hole of the spring seat of the axle. While holding the leaf spring against the spring seat, move the U bolt plate under the leaf spring, lining up the center bolt with the center hole in the U bolt plate.
Holding the U bolt plate in place under the leaf spring, slide the U bolt through the U bolt holes in the U bolt plate. Slide a washer and twist a U bolt nut hand tight to keep the U bolt plate in place. Place a washer and U bolt nut on to each remaining U bolt and hand tighten.
You may need to jack the RV higher to allow you to seat the leaf spring properly to the axle’s spring seat.
The other eyelet of the new leaf spring should be lined up with the spring hanger. While watching the eyelet of the leaf spring and spring hanger bolt hole, jack up or lower the frame of the trailer using the jack that is already holding the frame up. Remember to lower the jack stand if you need to lower the trailer to line up the eyelet and bolt hole of the spring hanger.
The axle may not be in the correct position since it was attached to a broken leaf spring. The leaf spring may look too short if the nonbroken side of the leaf spring was attached to the equalizer. The spring shackles will probably be swung toward the equalizer.
Use x-chocks between the tires to push the tires away from each other. Ratchet the x-chock until the eyelet lines up with the spring hanger’s bolt hole.
You can also position a second bottle jack under the spring bolt of the equalizer. Jack it up to swing the equalizer to be closer to the opposing side’s equalizer position. This will push the eyelet of the other end of the leaf spring toward the spring hanger.
Test fit the last spring bolt. Push it through the spring hanger and leaf spring eyelet to make sure they are lined up. If it does not fit, adjust one or both jacks or x-chock until they line up.
Remove the test fit spring bolt, grease the bolt well, and slide the bolt in from the outside in. This will allow you to have the lock nut screw on from the underside of the trailer. You will also have free swing of the socket wrench if leaving the wheel on.
Hand tighten the lock nut onto the greased spring bolt.
How tight do you tighten the nuts on the U-bolts? According to an etrailer expert, U-bolts 9/16″ diameter should be torqued to 64 – 95 foot pounds and 3/8″ diameter U-bolts should be torqued down to 30 – 50 foot pounds.
Once the U-bolt nuts are torqued to spec, use an adjustable pipe wrench pliers and a socket wrench with the appropriate deep socket to tighten the shock nut.
Use an adjustable wrench and a socket wrench to tighten the lock nuts on each of the three spring bolts. The spring shackles need to be able to move in order for the leaf spring suspension to work correctly. Tighten the lock nut and then loosen it about 1/8 – 1/4 turn.
Secure the brake wires with zip ties so they do not become damaged from the suspension. I zip tied the wires to each U-bolt leaving slack in the wires for suspension travel.
Remove the X-Chock from between the tires. Remove the Jack stand from under the RV frame. Lower the bottle jacks, starting with the one under the equalizer, and remove them from under the RV.
Your RV Leaf Spring is now finished and ready to take you to your next destination. Excellent work!
I highly recommend watching the step by step video before starting your broken leaf spring repair. Prepare your self as much as possible so you know what to expect.