Project

Gearbox Housing Bearing Bore Rebuild

Spun, worn-oversize gearbox bearing bore rebuilt cold and reformed back to dimension without machining a new housing.

The challenge

What was failing

A gearbox bearing bore spun in service and wore oversize, so the bearing outer race no longer seated tight in the housing. Once the bore opens up, the bearing creeps and turns in the bore instead of holding fast, and that wears more metal away while the shaft runs out of alignment. Left that way, the gearbox runs hot, loses the bearing, and risks taking the shaft and gears with it. The plant needed the bore back to the correct dimension, but the cast housing was not something they could quickly replace and there was no spare on the shelf.

Gearbox casing repaired and rebuilt by AAS
Our approach

How AAS approaches it

We take the housing into the shop and clean the bore back to sound metal so we can see how far the wear has gone. We rebuild the worn bore cold with Belzona 1000 Series composites, building up enough material to take the bearing again. Then we use a release agent on a mandrel sized to the bearing and form the composite against it, so the bore is reformed back to the correct dimension as it cures. Working cold means the cast housing sees no heat and no distortion, and we never have to set up a machine to bore a new seat.

Assess and measure

We inspect the spun bore, measure how far it has worn oversize, and confirm the bearing dimension the bore has to return to.

Surface preparation

We clean the worn bore back to sound metal and roughen the surface so the composite bonds to the housing.

Cold rebuild the bore

We build the worn bore back up with Belzona 1000 Series composites, working cold so the cast housing sees no heat or distortion.

Reform to dimension

We apply a release agent to a mandrel sized to the bearing and form the composite against it so the bore cures back to the correct dimension.

Cure and return to service

We confirm the cured bore is on size, then hand the gearbox back so the bearing seats and the shaft runs in alignment.

What you get back

The result

Bearing bore reformed back to the correct dimension without machining a new seat
Spun, oversize bore rebuilt cold with no heat or distortion to the cast housing
Original gearbox housing saved rather than replaced, with no spare casting needed
Repair completed by factory-trained and factory-certified Belzona applicators
In the field

From the job

Repair and protection work of this kind, performed by AAS crews across Louisiana.

Capabilities used here

Where this work happens

24-hour on-call service

Have equipment that needs to stay in service?

Tell us what is failing. We respond quickly, and we offer 24-hour on-call service.

Call (225) 751-1930