Kubota BX w/D722

[Dobermanfan]

Hello everyone, new here. Got a nice little 2022 BX1880 at auction. Came with a bunch of attachments (5 ) so I came out pretty good considering the reason for the post.

Drove down to pick it all up, got there then got the story. Some old junk yard dog of a man bought all this stuff a few years back. Overheated it, dropped it off, heard the cost of repair ( neglect from not cleaning the screens ) so no warranty, said keep it. Basically it was repossessed months later as it sat.

Got her back, ordered head gasket and a few other parts ( Bent push rods X2 ), hood and some other cosmetic things.

Had the head milled properly, installed new gasket after getting #1 piston to tdc. and went to install the rocker arm and noticed one push rod was far too tight ( after loosening screw all the way still tight ). Took rocker arm assembly completely off again leaving push rods in. Turned fly wheel several times, no movement of push rods.

Now I didn't take the motor out and pan apart, dang I should have. Everything seemed to work, pistons looked good, cylinder walls good, pistons all went up and down with ease.

What am I missing ? Lobes shaved off cam ? Is there a broken timing gear ? Anyone experience such an issue ?

 

[North Idaho Wolfman]

Get the WSM for it, that will give you all the breakdown of the engine.

If your not getting any movement out of the pushrods, you have a serious issue.

You're going to need to pull the gear case (timing cover on other engines) and see what's going on.

 

[Dobermanfan]

Get the WSM for it, that will give you all the breakdown of the engine.

If your not getting any movement out of the pushrods, you have a serious issue.

You're going to need to pull the gear case (timing cover on other engines) and see what's going on.

Thank you very much for the reply.

 

[lugbolt]

stuck tappet(s) from sitting maybe? Cams are gear driven, ain't a whole lot that can be wrong there. Possibly been so hot that the tappets are just seized, if that's the case, there's probably other things wrong too (rod bearings etc)

 

[Dobermanfan]

stuck tappet(s) from sitting maybe? Cams are gear driven, ain't a whole lot that can be wrong there. Possibly been so hot that the tappets are just seized, if that's the case, there's probably other things wrong too (rod bearings etc)

That was a thought that crossed my mind last night. One was not seized as it came out when I was sucking/blowing gasket material off the block. I will be out there shortly to pull the motor, but I will certainly give those a little love tap and see if they are in fact frozen. At this point I'd consider myself very lucky if that was the case, or a gear sheared off the cam as I see those are replaceable.

I'll post later today in case anyone else in the future finds themselves in this situation.

 

[Dobermanfan]

stuck tappet(s) from sitting maybe? Cams are gear driven, ain't a whole lot that can be wrong there. Possibly been so hot that the tappets are just seized, if that's the case, there's probably other things wrong too (rod bearings etc)

I will say it was hot, you could see the burnt oil around the rocker arms and top of head. As mentioned I'll oil those tappet passages and see if I can free them out.

 

[Dobermanfan]

That was a thought that crossed my mind last night. One was not seized as it came out when I was sucking/blowing gasket material off the block. I will be out there shortly to pull the motor, but I will certainly give those a little love tap and see if they are in fact frozen. At this point I'd consider myself very lucky if that was the case, or a gear sheared off the cam as I see those are replaceable.

I'll post later today in case anyone else in the future finds themselves in this situation.

Tappets came out fairly easy with a strong magnet. Sadly the cam won't turn. So hands will be getting dirty today.

 

[Dobermanfan]

Just an update from yesterday. The cam has been sheered off at the timing gear. So found the problem, just a little larger than anticipated.

 

[GreensvilleJay]

Ooopsy ! Looks like a TOTAL rebuild is now required... could be a fun 'winter' project though

 

[Dobermanfan]

Ooopsy ! Looks like a TOTAL rebuild is now required... could be a fun 'winter' project though

well I don't see any damage to the main crankshaft or any damage to pistons,cyl walls. No metal contaminated as it was literally just sheered off on the timing gear. Should be a simple cam swap. I will take the block to the machinest just to make sure and have it inspected,cleaned, milled if needed.

 

[North Idaho Wolfman]

WOW , that's the first one I've ever seen that happen to.

 

[Russell King]

Calling @hagrid for expert opinion

But it looks like it may have been cracking over time and then sheared when the area became too small. There should not be much torque involved in the camshaft unless it is used to drive a pump or something similar.

 

[Dobermanfan]

WOW , that's the first one I've ever seen that happen to.

Well I'm not sure if I should be proud
Of that or not.... yeah it sucks but these really are easy to work on once you get familiar with them.

hope to have a cam and back from machine shop within a week. Will keep posting progress if anyone is trying to tackle the same.

 

[PoTreeBoy]

WOW , that's the first one I've ever seen that happen to.

I heard of a rookie running the rocker adjusters all the way down on his small block chevy, then hitting the starter to fire it up. Snapped the cam right off. Maybe a previous owner jammed the valve train?