BX 23 strange engine knock ?

03marauderman

Member

Equipment
Kubota BX 23S
Sep 27, 2018
69
1
8
Plattekill
I have a BX 23 bought new 2-1/2 years ago, It currently has 38.4 hours....This weekend I needed to dig a 10ft. trench with the backhoe on a side slope...kinda dangerous I know... As I was positioning the tractor with it listing to the left with the front slightly dipping forward, I heard what sounded a distinctive lower engine knock....The engine RPM was low as I was very cautious in positioning the tractor...The knock went away when I raised the RPM...I dug the trench... When I lowered the RPM again to get the tractor on a level plain the knock came back intermittently and driving it back to the tractor shed, all was fine, like nothing happened....The oil was at the full mark? I'm concerned, as now its out of warranty....Any thoughts?
 

whitetiger

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Equipment
Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
2,542
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113
Kansas City, KS
It is most likely just the engine mounting bracket tapping your frame. These brackets bolt to the block and are mounted in the frame on rubber iso mounts. The three-cylinder engine vibrates a lot at low RPM and moves side to side quite a bit. Add tractor setting on a slope sideways and your engine moves a little more towards Downhill.

You could remove your underhood cover and set the tractor back on the slope to verify, but that probably is what it was.
 

1964vette

New member

Equipment
BX23S TLB 60" belly mower
Mar 1, 2018
7
0
1
Buchanan VA
I second that, I have the same tractor and it done that t to me, the motor mounts are soft. Enough to allow for the bracket to contact frame
 

03marauderman

Member

Equipment
Kubota BX 23S
Sep 27, 2018
69
1
8
Plattekill
Seems strange that motor mounts have such flexibility, allowing the engine to touch the frame, through vibration...Just don't recall hearing a metal to metal contact....Is this a typical & common issue on Kubota's?
 

dirtydeed

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B2650 BH77, U27-4R2, BX23TLBM, box blade, rear blade, flail mower, Stump Grinder
Dec 8, 2017
2,854
3,102
113
Wind Gap, PA
Had the same thing happen to me once while on a side hill. Yes, they do shake quite a bit at low rpm. I had to replace the muffler and many air filter brackets on my old BX23 (2006). Finally gave up on the air filter brackets and zip-tied/bungied them.

Just for kicks, watch for the vibration when you shut the engine off (with hood open) from a low idle.
 

03marauderman

Member

Equipment
Kubota BX 23S
Sep 27, 2018
69
1
8
Plattekill
Oh...I've seen the vibration when shutting down...I got spooked when I heard that knock as it didn't sound like metal clanking....but I should have realized when the tractor was level, the sound was gone...Had it been internally the knocking would be constant...still think the motor mounts should be stiffer.....