L48 HST issue

[Jason280]

I have an '03 Kubota L48 backhoe with the HST transmission and around 850 hrs. Today, I was clearing a small lot behind the garage when the rocker pedal for forward/reverse felt like it bound up, to the point it wouldn't "rock" forward or backwards. I played around with it a bit, and now it will function fine in reverse, but only travels very slowly in forward (despite L/M/H selection). The pedal feels like it is "rocking" correctly in reverse, but not quite right for forward. It almost seems like the rocker linkage is off, as though its not rotating far enough forward....but I am not sure. I'm concerned it might be something potentially wrong internally, but I am not sure how to troubleshoot.

Is this a common issue with any of the HST tractors from this era? Any suggestions?

 

[seville009]

I don’t know what you were clearing, but if it was sticks and brush, look under the tractor to make sure that nothing (like a stick) is jamming anything.

 

[Smokeydog]

Guess some caught up debris. Once had some dried weed stem jam in the HST pedal linkage that looked liked the control rods. Took looking a second time to clear it.

There’s at least one associated grease fitting on the HST pedal.

 

[rScotty]

No, there are no common problems with the rocker or HST transmission other than getting debris caught in the rocker.

I had a problem with my rocker control on the M59 - but nobody else seems to have had the problem unless yours does. Symptom was that the rocker felt wrong and would not rev up in gear - although the tractor would still move in low at an idle and I could still drive around slowly using the backhoe creeper lever..... I don't know if the L48 has that lever, but if so give that a try.

From under the right side of the tractor I finally figured out that one of the things that the rocker does is push and pull on a wire control cable that goes back about a foot and wraps around about a 4" diameter steel drum. Moving the rocker is supposed to rotate that drum - which then does something in the transmission - I'm not sure what. Anyway, that control wire looks like a bicycle cable and I found by accidently pulling on it that the stranded inner cable had broken inside of the outer protective cover. Messicks had the part and I was able to idle around until it came.

It was just a matter of hooking up the new cable. Not easy, but more picky than difficult. No adjustment necessary.
rScotty

 

[Jason280]

Figured it out.

A small tree stump was able to wedge itself in between the outer frame bars and into the linkage, and bent (not sure what they're called, still have to find a schematic) a couple pieces.

I *think* this is called the neutral assembly arm, I was able to mostly get it straightened back out....

I'm not sure about this piece, at least how its supposed to be oriented. I assume it should be perpendicular to the trans, that way it keeps the return spring oriented straight. I didn't want to bend it too much, didn't want to break it and then have to weld on a new piece.

I was able to get it all back together, and wouldn't crank at first....had to adjust the orientation of a safety switch on the neutral assembly arm, but now everything seems to be back to normal.

 

[Smokeydog]

Good job on repair.

I like parts manuals for their pictures and diagrams. Sometimes hard to find. Most of my manuals come used via eBay. Not only helps save money for DIY maintenance but have always helped sell quickly and at a premium price.

Once registered, Messicks has good parts diagrams, names, availability and prices on their website that’s helpful in repair.

Like the all metal, simple ruggedness of the L48.

 

[rbargeron]

I'm a little late seeing this - yes, that v-notch piece is the "neutral holder". My L48 is the same I think - lots of pieces in that linkage to tangle with brush! - related reading on an old L48 and HST saga here.

 

[Jason280]

Any chance you have a pic of the mount that holds the front of the return spring?

 

[rbargeron]

Your spring looks usable - anchor point doesn't look too fancy - just a fixed tie-off. It's pull strength isn't critical. The hydraulic damper is spring-centered too. The bent attachment tab is soft steel and should survive careful straightening. Dick B.