I have a late 90's 8875 and about a year ago, shut it down and went to go start it back up to just hear the starter motor spin and not turn the engine over. Of course it was in the middle of someone's driveway and the boom was down... after what seemed like an eternity, got the starter out and the starter gear was worn right down... had the starter rebuilt and put it back in... all is well. Probably put about 40-50 hours on the machine since then and the same thing happened again.. only this time, only a 3rd of the starter gear and a 3rd of the flywheel gears were chewed right up.. anyone ever have anything like this happen before? I'm not the original owner of the machine so I can't say what is what, but its frustrating to say the least.
You need a new flywheel ring and starter drive.......at the same time.
We are almost certain there wasn't any damage to the flywheel the first time. That's the only reason we didn't replace it. I just ordered a "ring gear" that supposedly is pressed onto the flywheel somehow. This thing, although a beast, has certainly been a nuisance. It also won't ever start in the run mode... only service mode. All fluids etc are up to par with no warning lights.
Sounds like the flywheel was fine when you replaced the starter and 50 hours later the ring gear is chewed up? Did the starter pinion engagement sound a little weird after the rebuilt starter was installed? The rebuilt starter must be wrong. Incorrect starter drive, different pitch of pinion teeth, something. That sucks. Like Vetech63 said, new ring gear and a new starter. Double check for correct pinion teeth pitch.
Any strange noises? Had some chewed starters from sticking keyswitch or relay causing it to intermittently try and engage while running.
The machine is started up and shut down alot. It is just a spare machine that gets very infrequent use. Nothing sounded different when I fired it up, but then again, on these machines, the engine is so far behind you and everything is so loud, you can't hear much of anything anyway. The one very odd thing that happened one day after starting it up was that my voltage was showing low (while operating right after startup). I thought nothing of it. The ignition is brand new as well. I am going to try and mate the ring gear and starter up once it's all out and see how they mesh. Not much else I can think of. But, what a disaster this has turned out to be. Lol
Nothing that I could find or hear. But being outside of this machine while it runs, I don't think I'd hear it anyway. I may just replace all relays anyway to be sure while we are doing this.
Generally flywheel ring gears are installed using heat. An oxy-acetylene torch works fine to get the ring gear hot all the way round and once it expands far enough it will simply drop on. Make sure you get the large bevel on the ring gear facing the right way though, otherwise it could cost you another ring gear.
MarshallPowerGen may be on to something. I like the way he thinks. There may be a underlying issue that caused the original starter to fail. I would study the wiring diagram and take a hard look at all the parts in that circuit. New ignition switch and the low voltage issue you pointed out....... sounds like the starter is working when it’s not supposed to.
Thank you for the heads up. I will definitely pay attention to that.
I agree... and I hope that isn't the case. My brother in law is a heavy equipment mechanic for CAT and will be doing all of the work. He even suggested installing a small warning light inside the cab that would come on should the starter be engaged. That way, even if I cant here it, I can see it and be warned about it when it happens and shut her down.
If the starter sticks on, the internals of the starter will be melted. No ifs, ands, or buts about it.
Can't be the case then.... the starter electric motor turns freely each and every time. Hasn't ever been the electric motor or solenoid that has seemed to fail. Always the gear
I've had starter switches get funky and starters stick in for several minutes before we figured out what the noise was, diesel starters tend to be more robust, especially Denso types. As Nige suggests a bit of heat works a treat, but don't get carried away. A disk won't expand all that much but a ring expands along the length of the material, if the steel turns a straw color you're probably past the point where it changes from "No way in hell I'm fitting on there" to dropping on and rattling until it cools some.
Thanks everyone. It's going to be a "when we get around to it" type of job, but I will most certainly post what happens
Here are a few pictures of what we found taking the starter out...
I'm leaning toward wrong starter.
When you try to start in run mode does ERR02 show in the display? If so you most likely need this Start Interlock Relay.
I'm hoping that's all it is.... I took the starter that was in the machine out the first time it happened and brought it to a repair shop that rebuilds starters... first thing I'm going to look at is trying to mesh the gears up once the ring gear is off to see how they mesh.
I've never seen that err02... it would have an F04 code which said overpressure of hydraulic circuit but a filter solved that. If it's in "run" mode and you try to start it, you just hear a click noise once... flip it to service and it fires right up. Ill look into that start interlock relay. Thanks
Your wish is our command.
just my 2 cents. i use bricks to hold the ring gear while heating it and go round and round with the torch. on starters that have an adjustment for depth, it should be checked and adjusted as necessary
I assume your ring gear looks the same all the way around? obviously they were making contact when the engine was running, and not just for a few seconds. I think I'd want to know why before I replace that ring gear. Ring gear really doesn't look too bad, it's ground off fairly evenly, I've depended on much worse ring gears in trucks when I was younger and dumber. I'd file those teeth lightly on the front and back edge, put a new starter gear in it, and figure out what's wrong before putting a new ring gear on that could be trashed again in a minute.
you should be able to tell from the wear pattern on the flywheel teeth and the starter drive as to how far the teeth were meshing. on a new drive, you should check to make sure the teeth are beveled on the correct side in case it was manufactured wrong. with some offshore parts you never know. also, on some starters, the lever for the drive may be able to be installed backward which would cause issues. just a couple of random ideas
Just because they mesh doesn't mean much. I had a situation that the starting motor had 1 too many teeth on the pinon drive. It would start the engine, but it chewed up two ring-gears. I found two broken off ends of starting motor shafts laying in the bottom of the bell-housing when I removed it the first time. At the time I didn't really know what they were. I hope you find what is wrong and causing your problem and post back what it was.