Inside an Aircraft Wheel Overhaul, Step by Step

An aircraft wheel overhaul takes the wheel apart down to bare halves, inspects every component against the manufacturer's component maintenance manual (CMM), replaces or repairs what fails, and rebuilds and tests the assembly. At APSS the process runs in eight steps and ends with an FAA 8130-3. Standard turnaround is 10–15 days.

What happens before the wheel comes apart?

Step 1: Receiving and work order. The wheel is logged in and its part number and serial number are checked against the paperwork. The technician pulls the current CMM for that exact part number, because inspection methods, limits and schedules differ between manufacturers and dash numbers.

The tire-change count since the last overhaul also matters, because the CMM schedules overhauls and fuller inspections by that count. The removal reason matters too. A wheel that saw a hard landing, a runway excursion, a flat-tire roll or an overheat needs the extra checks the CMM calls for after that event. Tell APSS the history when you send the wheel.

APSS services about 96 wheel part numbers from BF Goodrich, Meggitt-Parker, Messier-Bugatti and Cleveland. Check yours on the capability list.

How is the wheel disassembled and cleaned?

Step 2: Deflation and disassembly. The tire is deflated completely before anything else is loosened. The CMMs call for a deflation tool rather than pulling the valve core. The tire is then demounted, the tie bolts are removed, and the wheel halves are separated. Bearings, seals and O-rings come out.

O-rings and packings are discarded once removed. They do not go back into the wheel.

Step 3: Cleaning and paint stripping. The halves are cleaned and the paint is stripped. Penetrant inspection needs bare metal to show a crack. The CMM controls how paint and coatings are removed, because abrasive blasting can mask a crack.

How is the wheel inspected?

Step 4: Nondestructive testing (NDT). APSS performs NDT in-house, with inspectors certified to NAS 410 / SNT-TC-1A, Level II minimum. The CMM specifies the method for each part.

Method	Part	Why
Dye penetrant	Wheel halves, whole surface	Shows surface cracks on stripped metal
Magnetic particle	Tie bolts	Finds cracks in steel fasteners
Eddy current	Bead seat area	Finds cracks without stripping paint; the standard check at every Tire Change
Hardness and conductivity	Overheated wheels	Checks for heat damage to the wheel material

Step 5: Visual, dimensional and parts evaluation. Every component is checked against CMM limits.

• Wheel halves: corrosion and pitting, thread condition at the valve and fuse plug ports, and out-of-round or buckling after an overload or overheat.
• Bearings: cleaned and inspected. Bearings with spalling, etching or nicks are discarded; bearings that pass are reused.
• Tie bolts and nuts: a broken or loose bolt is replaced along with the bolts next to it, and some CMMs require the full set when several are affected. Self-locking nuts have reuse limits.
• Fuse plugs: inspected and replaced on condition, after an overheat, or as the CMM directs.

What happens when a part fails inspection?

Some findings are repairable. If the defect is within the CMM's repair limits, APSS notifies you and re-quotes the order before continuing.

Some findings end the wheel's service life. Under the CMMs, these are grounds for rejection:

• A crack in a wheel half
• A wheel rolled on the runway on a flat tire
• An overheated wheel with hardness below the limit
• Corrosion or pitting beyond repair limits

Stripped valve or fuse plug threads mean the affected wheel half is replaced. An unrepairable wheel is red-tagged and rejected. If you need a wheel back fast after a rejection, see Aircraft Wheel Exchange vs. Outright vs. Repair.

How is the wheel refinished and rebuilt?

Step 6: Refinish. Stripped and repaired areas get a chemical conversion coating, then primer, then topcoat, per the CMM.

Step 7: Reassembly. The wheel goes back together to the CMM:

• New seals and O-rings installed
• Bearings repacked with grease
• Tie bolts and nuts installed and torqued to CMM values
• Tire mounted with its balance mark aligned to the wheel's heavy point or valve, as the CMM directs
• Tire inflated with dry nitrogen from a regulated source

A separate wheel balance is available for $150 per wheel when you need one.

How is the overhauled wheel tested and released?

Step 8: Leak check, final inspection and release. Every wheel is leak checked. The assembled wheel and tire are inflated with dry nitrogen to operating pressure in a safety cage, and leak-detection solution is applied around the tire bead, the joint between the wheel halves, the valve and the fuse plugs. Escaping gas shows up as bubbles.

A new tire also stretches after its first inflation. A pressure-retention hold, often called the stretch period, normally follows: typically 12–24 hours, with the allowable pressure loss set by the CMM. The stretch period can be waived, which is how a same-day AOG turnaround is possible. The leak check itself is never skipped.

The test pressure is the aircraft's operating pressure, as the CMM specifies, not an elevated proof pressure.

After a final inspection, the wheel is released with an FAA 8130-3 identifying the part number, serial number and work performed.

What does an overhaul cost compared with a tire change?

Service	Nose wheel	Main wheel	Turnaround
Wheel Overhaul	$650–$825	$750–$925	10–15 days (7 or 4 expedited)
Tire Change	$450–$625	$500–$675	48 hours

Prices are labor only. Parts, shop supplies and freight are billed as incurred. An overhaul can be expedited to 7 days (+$200 per wheel) or 4 days (+$400 per wheel).

A Tire Change skips the teardown, paint stripping and refinish, and relies on eddy current NDT at the bead seat. The CMM schedules a full overhaul every few tire changes, and immediately after an overload or overheat. Wheel Overhaul vs. Tire Change explains how to tell which one your wheel needs, and the wheel overhaul service page has the details.

Get a quote. Call (214) 337-3328, email sales@2aps.com, or send your wheel part number through the contact form or request for quote.