Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Trailer Towing and Tow Vehicles Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 01-23-2015, 12:16 PM   #1
Junior Member
Commercial Member
Join Date: Nov 2014
Posts: 12
Replacing leaf springs on a trailer

Trailer Leaf Springs

One of the major components of a trailer’s running gear is the leaf spring. These provide an inexpensive and effective method of cushioning the ride of a trailer, thus protecting the cargo on a trailer from the shock of rough road surfaces. The springs also protect the rest of the running gear e.g. axles from damage. Occasionally, springs will need to be replaced prematurely due to hitting a pothole or in the case of a boat trailer, excessive corrosion.
In a leaf spring system, the springs are mounted to the frame-mounted hanger (or shackles) with a bushing and fluted shackle bolts. The axle in this system is fastened to the leaf springs with u-bolts (called a tie plate kit).
In recent years, some trailer manufactures have added the newer Torsion Axle to their line-ups as an option. The cushioning function is “built-in” to the axle and this precludes the need for leaf springs. However, you will find that most trailers on the road today have the leaf spring design.
There are several components that make up a leaf spring; the leaves, center-pin, straps and eyes. The number of leaves, the width, thickness and the heat treatment of the leaves all can affect the Load Rating of the spring. The springs have a load rating from the manufacturer and matching this to your trailer is a primary concern when replacing springs. Typically, we recommend that you replace your springs with the same part that was originally on the trailer so that it matches the rest of the running gear components like axles, coupler, brakes and tires / rims. Also, we recommend replacing both springs on an axle even if only one is damaged.
Many trailer manufacturers recommend that the springs be replaced approximately every five years as part of the maintenance plan.
There are several types of leaf springs used on trailers. The double eye spring is unique in that it mounts to the spring hangers using a pair of shackle links. Measuring this spring for replacement is to measure a straight line from the center of the front eye to the center of the rear eye. This measurement can be done on the trailer.
The Open Eye Slipper design uses a special hanger that allows it to flex. This system does not use shackle links. It is also measured on the trailer from the center of the front eye to the center of the rear shackle bolt
The Hook-End Slipper spring is measured on the trailer from the center of the front eye to the middle of the rear spring hanger.
The Radius End Slipper and the Flat End Slipper are both measured on the trailer from the center of the front eye to the end of the spring
Boat trailers face the same road hazards as utility trailers plus the corrosion that is caused by immersion in water, especially salt water. Several attempts have been made to design springs that will not corrode but these have met mixed reviews.
In salt water, salt crystals work their way between the leaves, causing corrosion from the inside out. The best way to prevent this from happening is to rinse the springs in fresh water immediately after immersion in salt water. Also, the best treatment to prevent corrosion is to use a product like CRC Marine Corrosion Inhibitor. This is a spray that will deposit a wax-like substance on the springs, inhibiting water and salt crystals from spring leaves.

EasternMarine is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 01-27-2015, 05:51 PM   #2
Senior Member
Ray,IN's Avatar
Join Date: Aug 2001
Location: North America somewhere
Posts: 23,957
I've towed trailers for several decades, and never heard anyone or any trailer mfgr. recommend replacing springs-at all, let alone every 5 years.
What is more important IMO, is replacing stock shackles and bolts with a "wet kit", as OEM 1/4" thick shackles wear out within 5 years of camping.
2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy
Ray,IN is offline   Reply With Quote
Old 01-28-2015, 07:54 AM   #3
Junior Member
Commercial Member
Join Date: Nov 2014
Posts: 12
Ray - The above article was meant for all trailers, including boat trailer, equipment trailers etc. I just got off the phone with a tech guy at Dayton Parts who said he would not replace trailer leaf springs as long as they are still functioning properly. That being said, a piece of steel can only take so many flexes before it will fail.
On a commercial trailer used all day everyday, I can still see doing a spring replacement as a PM to prevent a broken spring on the road.
I agree that shackle links, shackle bolts, equalizers and bushings should be inspected and lubed periodically.
Thanks for reading and discussing.
EasternMarine is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Trailer Axle Spindles EasternMarine Trailer Towing and Tow Vehicles Discussion 1 12-11-2014 05:43 AM
2012 Ram 3500 Trailer Brake Problems? Ram3500 Trailer Towing and Tow Vehicles Discussion 5 11-07-2014 06:46 PM
WD Hitch setup on a light trailer matchrocket Trailer Towing and Tow Vehicles Discussion 2 02-16-2014 06:39 PM
Shocks for 1997 Safari with leaf springs wscwilliam Class A Motorhome Discussions 4 01-23-2014 10:13 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 05:52 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.