Regular trailer maintenance is critical to ensuring the longevity of your trailer, as well as making sure you are able to tow to your destination safely. Before towing, make sure your trailer and its many components are in safe working order. Worn or broken trailer parts can cause loss of control and injury may result. After any accident or impact, it is important to have your trailer professionally inspected.
You must inspect, maintain and service your trailer regularly to ensure safe and reliable operation. If you cannot or are unsure how to perform the items listed here, have your dealer do them.
In addition to this information, also check your trailer’s owner’s manual and the relevant component manufacturer’s manuals. Where discrepancies may exist, defer to the manufacturer's manual.
What follows is a recommendation for minimum maintenance. However, depending on the trailer usage, including cargo weight and mileage, as well as the environmental factors where the trailer is in use, your trailer may need more regular maintenance than that which is described below.
There will be a list of recommended service and inspection times for common trailer maintenance items below in the description.
Preparing your trailer for Maintenance and Inspection
To perform many inspection and maintenance activities, you must jack up the trailer.
Park the trailer in a safe environment on level ground.
- Check the trailers owner’s manual for suggested jacking points. If this information is unavailable, place jacks and jack stands under the outer frame rail to which the axles are attached. Some trailers are equipped with attached jack stands at the appropriate location.
- Make sure the jacks are clear of the wiring, brake lines and suspension parts including springs, and torsion bars.
- Do not use the trailer’s axle for support.
- Do not touch the wiring or hydraulic tubing.
- NEVER crawl under your trailer unless it is supported on properly placed and secured jack stands on firm and level ground.
- If working on one side of trailer, ensure the wheel on opposite side is blocked before jacking trailer.
- If you are removing the tire, you should loosen the wheel nuts before the tire is off the ground.
Axles, Wheels, Brakes
Before each tow, check the tire pressure to make sure it is at the level indicated on the tire sidewall or VIN label. Tire pressure must be checked while the tire is cold. Do not check tire pressure immediately after towing the trailer. Allow at least three hours for the tires to cool if the trailer has been towed for as much as one mile. Tires can lose air over a period of time.
Inspect tire sidewalls for bulges, bubbles, cuts or foreign objects. Repair or replace if needed to avoid a possible blow out while towing.
Inspect tire tread for worn or bald spots. Tread depth should be greater than 1/16th inch at any lowest point. Replace the tire before towing the trailer if the tire treads have less than 1/16th inch depth or the telltale bands are visible.
If you are storing your trailer for an extended period, make sure the tires are inflated to the maximum rated pressure indicated on the sidewall or VIN label and that you store them in a cool, dry place such as a garage. Use tire covers to protect the tires from the harsh effects of the sun.
Inspect each wheel for damage, out of round or bent. Damage can occur when the wheel and tire hit or bumps curbs. If the trailer has been struck, or impacted, on or near the wheels, or if the trailer has struck a curb, inspect the rims for damage. Replace any damaged wheel. Inspect the wheels for damage every year, even if no obvious impact has occurred
Lug nuts or bolts are prone to loosen right after a wheel is mounted to a hub. When driving on a remounted wheel, check to see if the lug nuts or bolts are tight after the first 10, 25 and 50 miles of driving, and before each tow thereafter.
Tighten the lug nuts or bolts in three stages to the final torque in order to prevent wheels from coming loose. Tighten each lug nut or bolt in the order shown in the following figure. Use a criss-cross or star pattern to evenly tighten the wheel nuts or bolts; see the following for recommended torque sequence.
Use a calibrated torque wrench to tighten the fasteners. Verify that wheel studs are free of contaminants such as paint or grease, which may result in inaccurate torque readings. Over-tightening will result in breaking the studs or permanently deforming the mounting stud holes in the wheels and will void the axle warranty.
See your axle manufacturer’s manual or your dealer for wheel nut or bolt torque specifications.
Wheel Hubs and Bearings
Wheel Hubs:Trailer wheel hubs connect the trailer tires to the trailer axle and allows them to spin. During inspection, check to see if they are damaged, corroded or improperly installed in order to avoid issues such as impaired steering or a broken axle. Check the hubs every 2,000 miles
Wheel Bearings: Trailer wheel bearings need regular maintenance, and with enough towing, replacement. The bearings are located within the wheel hub and reduce the friction between the wheel and wheel assembly. Because the bearings are hidden from plain view, it is crucial to remember to take the necessary time to open the wheel hub and inspect. A loose, worn or damaged wheel bearing is the most common cause of brakes that grab.
- To check your bearings, jack up the trailer and secure it on adequate capacity jack stands.
- Check wheels for side-to-side looseness by gripping the tire firmly with both hands and shaking. If it feels loose or rattles, remove dust caps and check for low grease or a loose axle nut.
Make sure to Repack bearings every year or 12,000 miles
Properly functioning brake shoes and drums are essential to ensure safety. You must have your dealer inspect these components at least once per year, or each 12,000 miles. Brake adjustment is not covered under the axle warranty.
The brake shoes must be adjusted after the first 200 miles of use, and each 3,000 miles thereafter. Most axles are fitted with a brake mechanism that will automatically adjust the brake shoes when the trailer is “hard braked” from a rearward direction.
Using pads or shoes without enough brake lining material can result in brake damage, create excessive heat and potentially cause the loss of braking capacity. Read your axle and brake manual to see how to adjust your brakes. If you do not have this manual, contact your dealer for assistance.
Brake Shoes – Properly functioning brake shoes are essential to trailer safety. To inspect brake shoe linings, remove the hub. Once the hub is removed and before you start any service or inspection, clean the brake assembly with brake system cleaner and allow it to dry. Never use compressed air or a brush to remove dust.
- Inspect both leading and trailing brake shoe lining for excessive wear. Hairline heat cracks are normal; however, if the lining is worn more than 1/16th inch, corroded, damaged or contaminated with grease or oil, replace the brake shoes.
- Replace brake shoes per the manufacturer’s owner’s manual. Otherwise, reassemble the hub and manually adjust the brake shoe.
These are just a few portions of trailer maintenance. For a full list check out the blog section on our website at www.thetrailerpartsoutlet.com