We have an old grove TMS 300 that has me stumped. It has an 855 cummins. The hydraulic pumps are driven by a gearbox that comes from the front of the engine. When driving this thing makes and awful grinding noise. If you pull the short driveshaft that goes to the gearbox running the pumps the noise mostly goes away. Now it only makes the noise under a good load. Downhill or coasting it goes away. the gearbox running the pumps has been gone through. It has a new clutch. The harmonic balancer visually looks goods and you can't see any vibrations. The front driveshaft had a crack in it and the pressure plate in the clutch had a crack all the way through. I think it's picking up vibration somewhere but it don't know where. This thing pulls like a scared rabbit. Engine runs great , power for days. If you wear ear plugs everything is great. Transmission feels solid, no trouble running through the gears. I just don't know what's making the noise.
Just gonna post an update. After doing some research the crane has an ntc350 engine. It was bolted to a rto6613. It had a 14" push type clutch. We couldn't keep a clutch in it so we changed out the clutch and transmission. It now has an rto14613 and a 15" clutch. It still screams. We're at the point where we're tempted to just run it until it blows and then we"ll know what to fix. The odd thing is how long it's held up. I've driven it to Louisville, all over Indy. We've used it regularly for a year or so now. It sounds like somethings coming apart at any second anytime your working the engine hard. We took it in to an engine shop and he thought it was the accessory drive. The problem is that to get to the accessory drive either the engine needs to come out or we need to cut a hole in the cab. Would a bad accessory drive scream for that long. It's completely dependent on the engine being under a hard long. Not rpm dependent at all. Doesn't make any noise when your using the crane part. One of you old timers has to have some experience with an 855. Or young timer. Heck I'm willing to listen to anyone's idea at this point.
That is a bit baffling Knep . Remember when you started the thread & thought about drive line U- joints & splines in phase . That 855 has a fluid filled harmonic balancer , Be easy to swap one out but I doubt that's what it is ? If the accessory drive pulley shaft on the engine was in that bad of shape I would think the seal would let go & be leaking oil ? My gut feeling is drive line or hydro pump gear box . You guy's have a service manual for the Grove TMS 300 ?
we have the parts and service manuals. Gearbox has been completely gone through. And the input shaft is the only thing that turns in there when the pump is disengaged. I tell you what Td it'd be a perfect crane for you. Climb any hill you point it and and has the full working jakes. If you can tolerate the sound of a bearing coming apart it'll work every day. Lol And a guy could probably get a good deal on it.
Kinda hard to tell where a noise is coming from when you're in that little dog house cab driving down the road. Since it pretty much only does it when the rig is driving under a hard load, like pulling a grade, but goes away when you back out of it going down the other side of the hill, maybe a problem with rear diffs sending noise back up the drive train?
Yeah ,The 300 sure sounds like a nice rig Kepptune :thumbsup Double check the drive lines for & aft on it & make sure grease is getting where it needs to be . Dry joint or out of phase will make some spooky noise .
Willie that may make sense. Like I say if you pull the small driveshaft that runs the pump it pretty much goes away. You can still here a bit of noise but it seems like that small driveshaft acts like an amplifier. I wouldn't have thought about the rear ends but it seems plausible. That'll definitely get looked at. It may end up getting new gears anyway. We've been talking about gearing it up to run about 60. It's got enough engine for it. Td the driveline looks good all the way back. Looks like it's all been replaced at some point. It's not a bad crane but it's not my favorite right now. At this point I mutter unkind things everytime I have to use it or walk past it because so far we've spent a fair amount of money chasing this problem and it's completely kicked my tail.
Had a similar sound on mine. Turned out to be one of the two bearings inside the fan hub. The sound would come and go, and those are not greaseable bearings. Its really hard to pinpoint where the noise is coming from if your driving or operating. Had a buddy come and listen to mine while I was running until it made the noise, even then we weren't sure where the noise was from. Mine is a Detroit, but I think some ntc have a similar drive set up on the fan drive. PS. I do envy your excess power, I've had a big cam on the floor of my shop for almost 5 years now, and have inframed the detroit once, waiting for the time to repower mine.