What Makes a Great Semi-Trailer Mobile Technician?

Trailer mechanics identify and diagnose mechanical and electrical issues inspecting, repairing, and maintaining the trailers’ components and systems for hauling large goods.

A mobile service technician can perform almost all the same repairs as are done in the shop. Here is a list of what you should expect from your mobile service technician.

Diagnosing Issues


New technology is a great thing, but it also has its bugs. Mobile techs can find those bugs, go right to the source of the problem, and fix it.

Most mobile techs perform manual OMEs/Resistance readings and testing voltages. However, at Utility Keystone Trailer Sales, our mobile techs skip all that with advanced diagnostics and electronic readouts of the ABS systems to read the Electronic Control Unit codes.

“It saves a lot of time for customers who need to get back on the road. Colt Sipe, Mobile Service Supervisor, says we can find the faults quickly compared to a shop doing manual readings with a multimeter.”

Mobile Reefer Repair

Your trailer technician will make sure your unit has fresh parts and oil to ensure the motor is running at its most efficient state.

Technicians will diagnose and fix any mechanical issues with the operation of the motor. And perform complete preventative maintenance, checking the entire operation of the motor, the moving parts, alternators, and compressors, and replacing any needed parts – Preventative maintenance should be performed every 3000 hours, on average.

  • Full oil change
  • Air filter
  • Fuel filters

Mobile Semi-Trailer Repair


Check the lights:

You’re out of service if you get pulled over for a light that’s out or flickering. If your marker light is flickering or flashing, or if it’s an LED and it’s half-lit, you’re out of service until you can get it fixed.

Your mobile tech will perform a light check at every visit.

ICC Bumper:

Look for any significant depressions in the ICC bumper.

Also, look for heavy rust, pitting, and a compromised frame.

Landing legs:

Your mobile tech will replace a set of landing legs, wing plates, k-braces, cross tubes, and sand shoe if needed.

We can do a complete assembly, including cross members plus landing gear assembly.


Shoes, drums, full rotor replacement, brake pads, etc.

King Pin and 5th Wheel Plate:

Examine the king pin, approach plate, and the 5th wheel plate to see if they are in good condition. If these things are damaged, you risk dropping the trailer as you go down the road.

You’re looking for a cracked 5th wheel pale or approach plate buckled upward into the trailer. Is the king pin bent or worn?

Your mobile repair technician can fix a crack in the 5th wheel plate, but if the king pin is bent, it needs to be repaired at the shop.

Bottom Rails:

Check the bottom rails for cracks, missing rivets, or significant dents.

Your mobile team can fix it and may not require that the trailer is taken to the shop for repair.

Cracks in the bottom rail:

The Mobile Technicians at Utility Keystone Trailer take special care with reefer trailers. Because of the foam, we are hesitant to weld the upper portion of the bottom rail. But we can weld the bottom rails, splice rails, weld a patch over them, and replace missing rivets.

Side Sheets:

A mobile trailer technician can repair damaged side sheets. They pull off the damaged sheet and replace it with temporary pop rivets to secure the new sheet – This is a single-man operation.

We recommend later bringing that trailer into the shop to remove the temporary pop rivets and secure the side sheet permanently with buck rivets – Buck riveting is a two-man operation.


Look for any signs of impact that could have caused a puncture in the roof. Your technician can patch the entire roof perimeter or large or small sections on dry vans and reefers. It is all done with pop rivets, which is not a problem. But if you’re repairing half of the roof, you would want to do squeeze rivets.

Utility Keystone’s mobile trailer service is staffed with eight service trucks and technicians to perform DOT inspections, PMs, tire & light checks, mobile reefer repair, and many other repairs to keep your fleet moving.

Contact a mobile semi-trailer technician in your area.