B7100 seized.

[torch]

I fired up the tractor this afternoon to clear the snow. Started fine, let it warm up for 10 minutes or so. Unplugged the block heater, started driving forward. Suddenly there was a loud rattle, like something rotating was hitting sheet metal. Engine was running at near full-throttle with no noticeable reduction in rpm. My first thought was something got caught in a driveshaft, but the PTO was still off. As I throttled down, the noise was clearly related to rpm. It suddenly stopped, and the engine was running as smooth as ever.

I thought maybe something was hitting the fan, so I shut off the engine and opened the hood. Nothing visible, no sign of damage to the fan blades. I though maybe it was a bit of ice that is now gone. I restarted without any problems, carried on, engaged the PTO and started blowing things out.

About 5 or 10 minutes later, the rattle suddenly reappeared. As I throttled down again, the engine suddenly stopped dead Now it seems seized. Starter motor goes "clunk" and I can't rotate the engine forward or backwards with a pair of channel locks on the front driveshaft extension. The dynamo rotates under the fan belt though. It's a B7100, so no water pump.

Any ideas what could cause such a noise, come and go, and then seize things tight? Clutch issue perhaps? Hydraulic pump?

 

[D2Cat]

Maybe remove the valve cover and see if something there tells you anything. Are you sure you have plenty of antifreeze in the radiator? Nothing dripping from anywhere? Is it HST or geared? How many hours? Maybe a bearing seized.

 

[SidecarFlip]

Torch... Per chance have you checked the oil level lately?

 

[torch]

Oil, hydraulic oil and antifreeze are all topped up. It has the occasional drip from the whistle when it's worked hard, but nothing substantial. It's an HST model.

 

[sheepfarmer]

Aargh torch, so sorry to hear that, the weather is so awful right now, can you get it in?

 

[North Idaho Wolfman]

Did you block the clutch pedal and try and turn the crank?
But if it did toss the clutch plate there isn't much room inside the bell housing so if it's around the flywheel that alone could jam it all up.

 

[torch]

Did you block the clutch pedal and try and turn the crank?
But if it did toss the clutch plate there isn't much room inside the bell housing so if it's around the flywheel that alone could jam it all up.

I'll try that. I was also thinking about engaging the PTO and trying to turn the mid-pto (rear has an over-run clutch)

 

[thepumpguysc]

Sure sounds like a rod bearing to me.?? but its hard to tell from here..

 

[torch]

Sure sounds like a rod bearing to me.?? but its hard to tell from here..

Anything is possible, but it didn't have that sound, to my ear. (Bearing in mind that I'm half deaf from 30 years of sirens.) This didn't have that same thunk that I associate with a rod bearing. Plus, a rod bearing usually fades in and out, becoming more pronounced under load. Also, bearings don't usually suddenly stop making noise altogether for 10 or 15 minutes at full throttle blowing snow.

The sound was more of a high-pitched rattle, like a weed trimmer line striking a tin shed. Definitely rpm related.

I tried blocking the clutch pedal down, engaging the rear PTO and turning it. Obviously it turns forward with moderate hand pressure due to the overrun clutch, but it won't budge backwards even with an 18" bar through the u-joint yoke. And the starter won't budge the engine. I think Wolfman is most likely correct -- something in the clutch let go and jammed things.

I got the FEL and the blower off (trust me, dragging a 400lb blower around by hand is not all it's cracked up to be!) and got the tractor into the garage. Next step will be to split it.

Just to confirm: I want to split it at the engine/bell housing joint, correct? This post by Service Dept Vic shows splitting it at the transmission, behind the clutch housing. That seems counter-intuitive to me.

 

[Lil Foot]

I had a similar incident with a Yamaha Rhino. I was running in the dunes near WFO when there was a loud bang and a loud rattle that was RPM related. I immediately shut down, convinced I had thrown a rod through the side of the engine. A quick inspection revealed nothing obviously wrong, but the starter only "clunked" as if the engine had seized. We were rigging a tow to haul my apparent scrap metal back to camp when I noticed a small piece of white plastic laying near the engine. Rhinos use a "leaf blower" fan on one end of the crank to blow air across the exhaust system to keep it from melting down & taking the Rhino with it. It uses a white plastic fan blade, which had exploded, jamming in it's housing. I pulled the cover, removed the broken bits, it fired right up and I putted back to camp. A new blade & I was back in business.
Hopefully, your problem is something similar.

 

[D2Cat]

Torch, yes split it between the engine and bell housing. Be sure to put some wooden wedges on each side of the engine just over the (front) axle. This keeps the engine from flopping over on one side when you finally get the engine freed from the bell housing.

I would block the rear tires real good and use some wood for cribbing, or a jack stand to hold the back. Just whatever you use make sure there is good support there. Use a floor jack on the front so when you need to you can just roll the engine away from the back.

 

[FishLife]

Hope it is something simple and not serious. Keep us posted.

 

[Russell King]

Is there any inspection port on the side of the housing? If so you can get cheap cameras like boroscopes and look in before splitting the tractor.

But I agree with the clutch diagnosis


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[torch]

I just hope that whatever is preventing it from rotating won't also prevent it from separating.

 

[torch]

Is there any inspection port on the side of the housing? If so you can get cheap cameras like boroscopes and look in before splitting the tractor.

It turns out that there is a small cover on the right side of the bell housing. Kubota calls it a timing cover, and it looks at the side of what I assume is the flywheel. No room to get a borescope past it, it's really close to the case, but it does appear that something was rubbing on it.

Just getting some lunch after spending the last hour getting the 4 muffler nuts off the studs. They were impressively corroded, and no room for a nut extractor. Had to heat them up to cherry red and work them back and forth with a selection of needlenose vise-grips and assorted wrenches. But I did manage to get them all off without breaking any studs.

I wonder if it would be worthwhile to pull the starter? That opening must have more room, right?

 

[North Idaho Wolfman]

It turns out that there is a small cover on the right side of the bell housing. Kubota calls it a timing cover, and it looks at the side of what I assume is the flywheel. No room to get a borescope past it, it's really close to the case, but it does appear that something was rubbing on it.

Just getting some lunch after spending the last hour getting the 4 muffler nuts off the studs. They were impressively corroded, and no room for a nut extractor. Had to heat them up to cherry red and work them back and forth with a selection of needlenose vise-grips and assorted wrenches. But I did manage to get them all off without breaking any studs.

I wonder if it would be worthwhile to pull the starter? That opening must have more room, right?

Why removing the muffler?
You could pull the starter, but again there isn't much room in there to see much of anything.

 

[torch]

NIW: I removed the muffler to remove the left side engine cover. Easier access to the bell housing bolts, especially since I left the cab installed.

Besides the obviously missing piece and missing spring, there's another crack beside another cushion spring that doesn't really show up in the photos.

Flywheel seems untouched, so that's a good thing. The throwout bearing feels like it's new -- no play or roughness at all. I could probably get away with throwing a new friction plate in there and reassembling it, but I'm on the fence about that pressure plate assembly.

The Kubota Canada parts website lists it at $216 but I wonder if one of those many, many dings could cause a fracture somewhere and bite me in the @$$ somewhere down the road. And that dark spot seems to be some sort of burnishing -- the plate may be warped. I haven't put it on the surface plate yet to check.

I can turn the engine and the input shaft by hand. Could have been a lot worse.

 

[Jchonline]

Great post, thanks for sharing all of the photos.

 

[Jim L.]

Good job and thanks for the pictures. You didn't waste time tackling this project.

 

[SidecarFlip]

Good old carnage... Glad I have a hydraulic shuttle. Wishing you the best on re-assembly