Case Study – Caterpillar Crown Wheel

Caterpillar Crown Wheel cryogenic treatment
At Controlled Thermal Processing, we hear success stories from the field every day. Here’s one satisfied customer that used our
deep cryogenic treatment services for his fleet of Caterpillar scrapers and saw huge improvements in performance.

Caterpillar Scraper Crown Wheels

For the last fifteen years we have operated fleets of 637 and 657 Caterpillar scrapers, regardless of which model machine is in use we have suffered a high incidence of single tooth crown wheel failure predominantly in rear diffs but not limited only to rear differentials.

During this time we did not experience a pinion gear tooth failure the tooth failures were concentrated 100% to crown wheel failure.
Two years ago two differentials were treated differently with the CAT crown wheels being refinished and then Deep Cryogenically Treated to increase strength with special attention paid to fitting during the diff rebuilds.

In early October 2012 one of these diffs failed, inspection found the primary failure was operator induced diff lock failure. All of the lugs were broken off one half of the diff lock, this metal made its way through the diff centre into the gear housing doing much damage in its passing.

The pinion gear suffered significant damage with sections of gear teeth breaking away, the sections of broken pinion gear as well as the lugs from the diff lock were ground to a paste as they passed through the gears with only one lug remaining when the diff was stripped.

 

single tooth crown wheel failure

tooth breaks caterpillar

caterpillar wheel rotor breaks

caterpillar failed half of diff lock

caterpillar diff lock lugs break away

The pinion gear suffered significant damage with sections of gear teeth breaking away, the sections of broken pinion gear as well as the lugs from the diff lock were ground to a paste as they passed through the gears with only one lug remaining when the diff was stripped.

caterpillar damage to diff housing

caterpillar

 

 

 

 

 

 

 

 

 

caterpillar pionion gear lost sections

caterpillar pinion gear damage

caterpillar typical diff lock lug

The crown wheel that had previously been prone to losing teeth prematurely had not lost a tooth yet there was evidence that much of the metal had passed through the gear with evidence of metal bruising and deformation in the root of the gear without causing failure.

caterpillar crown wheel impact marks crown wheel

caterpillar crown wheel

caterpillar crown wheel damage

caterpillar crown wheel impact

caterpillar crown wheel

caterpillar crown wheel

caterpillar crown wheel

caterpillar crown wheel teeth damage

caterpillar crown wheel intact cryogenic treatment

Previously the treatment of the diff was limited to theory however this is hard evidence that treating the gear significantly strengthened the component and had the diff lock not failed would most likely have continued to give good service.

Contact CTP Today

As you can see, deep cryogenic treatment of automotive components can dramatically improve the performance of vehicles and equipment, reducing maintenance costs and help your overall bottom line. If you’re looking for a way to improve the performance of your heavy machinery, construction equipment, High HP Road Racing Racing Diffs, Off Road Diffs etc.. reach out to us at Controlled Thermal Processing by contacting us online.