Bearing Inspection, Grease Packing and Seal Preparation
- Inspect bearing cones and cups while preserving matched sets.
- Remove contamination and pack bearings with specified grease.
- Prepare the hub with a packed bearing and a correctly seated new seal.
- Wheel chocks, floor jack and jack stands — Chock tires on level ground, then lift by the frame and support with appropriately rated stands according to the RV manufacturer's recommendations.
- Lug wrench, sockets and pliers — Loosen wheel nuts before lifting; remove wheel and spindle-retaining hardware during disassembly.
- Seal puller — Remove the grease seal for disposal without damaging the hub's seal bore.
- Solvent tray and lint-free cloths — Clean bearing components with suitable solvent and dry them without introducing lint; wear eye protection and appropriate solvent-exposure PPE.
- Bearing packer — Force specified grease through the bearing rather than merely coating its exterior.
- Hardwood block and hammer — Drive the new seal squarely until its outer face is flush with the hub's seal-bore face.
Begin on level ground, establish a clean location for removed components and chock the tires before disassembly. Loosen wheel nuts before raising the RV, then lift by the frame and support it on appropriately rated jack stands according to the manufacturer’s recommendations. Do not lean a removed wheel against the RV or its supporting jacks.
Remove the dust cap, discard the cotter pin and remove the castle nut and spindle washer. Grease can hold the washer against the nut or outer bearing, so account for it during removal. Cover the hub nose while withdrawing the hub to keep the outer bearing cone from falling. Remove the grease seal with a seal puller or equivalent and discard it.
Clean bearing cones with a suitable solvent and dry them with a clean, lint-free cloth. Examine cages, rollers and cup raceways for pitting, spalling, corrosion, flat spots, discoloration or other abnormalities. Used cones and cups must remain matched; replace a defective cone and its mating cup together, even when one component still appears serviceable.
Bearing-cup replacement requires precise seating against the hub’s retaining shoulder. Lippert directs technicians to consult Lippert before this work and recommends a certified service center. Clean the hub and cup bores, use a brass drift to move a cup evenly, and inspect the installed race for damage. A cup that is not fully seated can damage the completed assembly.
Remove old grease from the hub, bearings and spindle before packing. Machine packing is preferred, but hand packing is permitted: force grease through the wide end between adjacent rollers and work around the bearing until all rollers are coated. Lightly grease the cup race, install the packed cone and install a new seal squarely with a hardwood block until its outer face is flush with the hub’s seal-bore face. The specified grease is lithium complex, NLGI No. 2, with a minimum dropping point of 446°F (230°C). Inspect bearings every 36,000 miles or 12 months, whichever occurs first.
How It Works
Clean inspection and matched wear surfaces
Prepare a clean parts area, remove old grease from the hub, bearings and spindle, then clean bearing cones with suitable solvent and dry with a clean, lint-free cloth. Examine cages, rollers and cup raceways for pitting, spalling, corrosion, flat spots, discoloration or other abnormalities; used cones and cups must remain matched because their contact surfaces develop a shared wear pattern. Replace a defective cone and its mating cup together, even if the mating component appears serviceable, and inspect bearings every 36,000 miles or 12 months, whichever occurs first.
Packing creates an internal lubricant supply
Use lithium complex grease, NLGI No. 2, with a minimum dropping point of 446°F (230°C); never mix lithium, calcium, sodium or barium complex greases, and completely remove old grease when changing types. Machine packing is preferred, but hand packing is permitted by forcing grease through the wide end between adjacent rollers and working around the bearing until all rollers are coated. An exterior smear does not establish the internal lubricant supply needed to separate loaded rolling surfaces.
Cup seating and seal preparation
A bearing cup must seat precisely against the hub's retaining shoulder; Lippert directs technicians to consult Lippert before cup replacement and recommends a certified service center. For that work, clean the hub and cup bores, use a brass drift to move the cup evenly, and inspect the installed race for damage, because incomplete seating can damage the assembly. Lightly grease the cup race, install the packed cone, and install a new seal squarely with a hardwood block until its outer face is flush with the hub's seal-bore face.
Step-by-Step Procedure
0/8 doneBearing Inspection and Grease Requirements
| Physical bearing inspection | Every 36,000 miles or 12 months, whichever comes first |
| Grease consistency | NLGI No. 2 |
| Minimum dropping point | 446°F (230°C) |
Diagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| Cleaned bearing surfaces show pitting, spalling, corrosion or flat spots. | Inspect the cone's cage and rollers and its mating cup raceway; keep reusable mating components identified and together. | Replace a defective cone and its mating cup together. | Surface deterioration interrupts smooth rolling contact and can accelerate further wear. Basis: ccd-0011255 |
| A replacement cup is not seated against the retaining shoulder. | Stop assembly and verify seating and race condition; consult Lippert before proceeding with cup replacement. | The cup requires precise seating against the hub's retaining shoulder; Lippert recommends a certified service center. | Incomplete seating leaves the bearing support incorrectly positioned and can damage the completed assembly. Basis: ccd-0011255 |
| Grease coats the bearing exterior but has not reached between the rollers. | Remove old grease and repack by machine or force grease through the wide end between adjacent rollers, working around the bearing. | All rollers must be coated; use lithium complex grease, NLGI No. 2, with a minimum dropping point of 446°F (230°C). | Smearing grease onto exposed surfaces does not adequately fill the bearing's internal working spaces. Basis: ccd-0011255 |
| The new seal is tilted or its outer face is not flush. | Check seal alignment against the hub's seal-bore face before continuing assembly. | Install a new seal squarely with a hardwood block until its outer face is flush with the hub's seal-bore face. | Uneven installation can distort the seal and compromise grease retention and contamination exclusion. Basis: ccd-0011255 |
At the Bay: Diagnose the Case
CASE 1 / 4
Cleaned bearing surfaces show pitting, spalling, corrosion or flat spots.
- Test
- Compare
- Correct
Select the next check
Basis: ccd-0011255. A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Never work under an improperly supported RV or lean a removed wheel against the RV or supporting jacks.
- ✕ Account for the spindle washer; grease can hold it against the nut or outer bearing.
- ✕ Cover the hub nose during withdrawal so the outer bearing cone cannot fall.
- ✕ Discard the removed cotter pin and grease seal rather than setting them aside for reuse.
Quick Check
Practice only — not scored.
Plan the Service Sequence
Planning practice only. Follow the applicable manufacturer's instructions, employer safety program and qualified supervision on real equipment.
Plan the first action. Compare the service steps with the bay mistakes.
Hands-on: Shop Test Equipment
Dial Indicator — Bearing End Play
Magnetic-base dial indicator (0.001 in) on the hub face, spindle nut adjustment
🛠 Equip your bay for this test →Symptom: Bearing service — set end play after repack.
Spec limits used
- 0.001–0.010 in — Allowable end play, double-nut wheel end (Dexter 9-15K service manual, p.64)
- 0.008 in — Nev-R-Lube 50 mm max axial end play (Dexter 059-831-00)
- illustrative only — Face runout limit (General shop practice)
Simulated readings for practice. Always follow the manufacturer's procedure and values on a real trailer.
Source: ccd-0011255 — 2-9