I recently had to pull my engine after losing all power to my hydraulics. ( The hydraulic pump is fine). The problem: All of the bolts (16) attaching, the what is commonly refered to as, the "fibre gear" to the flywheel were sheared off. The engine still ran fine. The engine has now been overhauled and a new "fibre gear" installed. I am very nervous about reinstalling the engine without knowing what caused the bolts to shear.Does anyone have suggestions as to why the bolts sheared ? This may be coincidental but when I lost all power I also discovered a broken hydraulic line underneath the machine. I lost a considerable amount of fluid. Thank you all very much.
Don't know about the Ford, but Clark fiber gears were fastened with special bolts, they had thread locker epoxy on the threads so when they were tightened and let set up they wouldn't back out. They also had the head drilled and safety wired as double insurance. They also used special slightly cone shaped washers to spread the load on the fiber material.
Thank you Oldseabee. The fibre gear was indeed fastened with drilled bolts and wired as you described. Do you have any idea as to a root cause of the bolt failure? Please correct me if I'm mistaken but my understanding is the gear is made of fibre to prevent a catastrophic mechanical failure. It is the weekest link so it fails first in the event of an underlying problem. Better a simple fibre gear loss than say a crank shaft. What should I be looking for, if anything, as the underlying issue ? Torque convertor ? Slipped transmission clutch ? I am a first time heavy equipment owner. I have had the machine since 09'. It takes awhile but I am starting to get to know and understand the machine. Thank you.
Bolt failure can have several causes. Under torqueing can cause low clamping force on the fibre gear allowing it to move and work the bolts back and forth. over torqueing will over stretch the bolt weakening it. If the old bolts were used to replace the fibre gear, they wouldn't have the proper thread locker epoxy to hold them in place and will have been stretched by the initial tightening so to get torque will require further stretching. To insure that the job is done right this time use new proper bolts and torque in a cris cross pattern, first snugging them up then go back and torque them. Make sure that the safety wire is twisted in a manner to prevent loosening of the bolts, the pull of the wire should be in a clockwise direction. Lastly, probably should do this first, check flywheel run out both on the circumference and the face, flywheel could be warped.
It appears this is the first time the engine has been pulled so I am assuming the fibre gear and the installation is original. After we pulled the engine and discovered the sheared bolts I simply picked the fibre gear off of the flywheel. It appeared to be fine but then broke quite easily around the bolt holes into 3 pieces. I ordered a new fibre gear. The new fibre gear assembly is different than the original one with the wired bolts. This time there is a solid steel ring with an identical bolt hole pattern as the fibre gear. The ring attaches to the outside of the fibre gear with the bolts going through the ring and then the fibre gear into the flywheel. The gentleman who rebuilt the engine installed the fibre gear. I will ask him if he followed your procedure. I will check the flywheel run out as you suggest. If that is good then is it safe to assume that the sheared bolts were caused by normal wear and tear of a 22 year old machine ? Thank you oldseabee.