We have had a problem with our machine breaking grippers for our Cat 40 tools. The remedy is to adjust the magazine chain tensioner. Loosen the 3 hex bolts under the rear sprocket where the tools are loaded. The adjuster is the bolt on the extreme right side. Once the chain is properly tensioned the tools line up on the changer. Some of our tools were as much as 1/4 in too low. This shoud be checked every 6 mo.