B7100 HST-D Will Not Move

[ezlife]

I have a 1980ish B7100 HST-D.

Rear 3 point works fine.

Tractor will move in any direction or any gear.

It makes a loud rattling noise when the clutch is out.

It is perfectly quiet with the clutch fully in.

Rear PTO is not working.

This occurred while mowing, I first noticed the blade noise decreased, so I thought maybe the belt, so I stopped and checked the belt. Intact.

I raised the deck, no problem seen there. Then I tried to move. Nada.

I dropped the mower and pushed the tractor to flat ground and checked the hyd fluid. Perfect.

Then I got it in the workshop and dusted off the shop manual. Turned to troubleshooting the hydrostatic transmission, (am I in the right area even?)

It says first thing to check is the input shaft, if it turns, then check fluid, linkage, vacuum, charge relief valve etc, etc... IF it doesn't turn then repair/replace.

So, how do I go about checking the input shaft? Is it something I can access and rotate by hand or what?

I guess I'm asking for a kinda blow by blow of what to do in what order.

I would love it if someone would tell me I don't have to split my tractor and can just pull off an access panel somewhere or crawl under the tractor and see what I need to see, lol.

My first instinct was to think throw out bearing, but since the noise goes away completely when the clutch is pressed, then that makes me think the clutch is working properly. Is this proper logic?

Not exactly sure what the input shaft is or how to evaluate it.

Thanks,

Kris...

 

[Egon]

Kris, if you do not have a PDF parts list send me your email address and I'll send you one.

 

[crbr]

I shot him one over just a few moments ago.

 

[alchemysa]

"Tractor will move in any direction or any gear."

I assume you meant Tractor will NOT move in any direction or any gear.

To view the input (propeller) shaft there should be a removable plate of some sort on top of the transmission tunnel. (Maybe there are other ways to see it but thats how I view mine.) With the engine running, the shaft should be turning all the time unless you have your foot on the clutch. HST Drive and PTO are are two somewhat independent systems that are both driven by the single input shaft. If both are not working then its probably an input shaft or clutch problem, (although I guess you could possibly lose both the HST and the PTO if there was a major disintegration inside the HST. Hopefully that's not the case.)

 

[franxalot]

My B8200HST did that last Fall. Drove it, shut it off, refueled, started up--NADA.

Checked fluid level. Plenty. Clean and colorless.

Loosened the banjo fitting on the hydraulics under the seat to see if anything was happening. Got some air, then a gurgle, then fluid. Has worked fine ever since. We figure that the pump check valve may have stuck and it lost prime???

Costs nothing to give it a try.
--Frank

 

[ezlife]

Sorry for the typo, I meant that it does NOT move. My bad. However in an attempt to salvage a little bit of pride, the subject title of the thread does correctly state "Re: B7100 HST-D Will Not Move". At any rate I stand corrected and thank you for pointing that out.

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Anyway, I crawled under the tractor with a trouble light and located what I now believe is the propeller shaft, going from the engine into some sort of I call it a coupler in front of the actual input shaft in the transmission.

In short, the propeller shaft is turning beautifully, but where it goes into the "coupler" there is a continuous shower of miniscule metallic bits where the splines on the aft end of the propeller shaft or the splines inside the coupler (or both) are not engaging.

The transmission input shaft consequently is not turning. So, if I'm very lucky maybe only the coupler thing needs replaced. I understand that there is no shortcut to splitting the tractor between the engine and the tranny, instead of in between the pto unit and the tranny if the input shaft itself was stripped.

Hillbilly solutions I have thought about to avoid splitting the tractor:

1) cutting the prop shaft in half and removing it, to get to the coupler, then replacing the coupler & shaft if needed and welding it back together.

2) welding the prop shaft to the coupler as is, not elegant, but maybe a 5 minute fix vs many hours and dollars.

Let the laughing begin, or add your own inelegant redneck ideas here...:confused2:

 

[Earl Ohl]

2) welding the prop shaft to the coupler as is, not elegant, but maybe a 5 minute fix vs many hours and dollars.

That's what I did on one of my old tractors. If possible try to weld it in some way that it can be accessed with a die grinder in case it ever needs to be taken apart in the future.

 

[Egon]

Just for curiosity:

Will the back wheels turn with the clutch in?

Can the coupler be moved back and forth?

Any splines from transmission side showing?

2) welding the prop shaft to the coupler as is, not elegant, but maybe a 5 minute fix vs many hours and dollars.

Before doing this make sure the transmission and range selector work properly.

 

[alchemysa]

So something inside part 030 is busted. You need to find out why the coupling or shaft is stripped. Don't go welding anything, you need to fix this properly. You don't want to wreck your HST.

I dont know for sure but i'm guessing you should be able to rotate the coupling and the input shaft of the HST when the pto is disengaged. If you can't then maybe something between the pto and the coupling is jammed.

Edit. Upon closer inspection of the coupler in the pdf it appears that the coupler contains 4 spring loaded balls. These may be some kind of safety mechanism to prevent more serious damage to the HST. I'm guessing the 'loud rattling' is these balls doing exactly what they are supposed to do. So, its possible that the coupling is not busted, and your problem is elsewhere. In other words, something 'else' is stopping the input shaft of the HST from turning. (i.e the pto assembly)

Another edit. Looking again, no they are not spring loaded and they are probably busted after all but you still need to find out 'why'.

 

[ezlife]

Just for curiosity:

Will the back wheels turn with the clutch in? I'LL CHECK THAT AGAIN BUT WHEN THE PROBLEM FIRST OCCURRED, I OPERATED EVERY CONTROL AND COMBINATION I COULD THINK OF, WITH THE CLUTCH ENGAGED I GOT THE SAME LACK OF MOVEMENT WITH THE CLUTCH IN EITHER POSITION. THE ONLY DIFFERENCE I COULD TELL WAS THE LOUD RATTLING NOISE.

Can the coupler be moved back and forth? HAVEN'T TRIED THAT, ARE YOU SUGGESTING I CHECK BY HAND FOR NOTICEABLE LOOSENESS OR SLOP, (I'M ASSUMING OF COURSE THAT IT SHOULDN'T MOVE AT ALL).

Any splines from transmission side showing? WHERE THE PROP SHAFT GOES INTO THE COUPLER IS WHERE I REMEMBER SEEING SPLINES, AS FAR AS THE BACK END GOES I'D HAVE TO LOOK AGAIN. I TRIED TAKING A VIDEO UNDERNEATH WITH MY CELL PHONE AND A DROP LIGHT, IT DIDN'T WORK SO WELL, BUT IF I CAN GET A DECENT VIDEO I'LL LEAVE A NOTE ON HERE SO ANYONE THAT MIGHT WANT TO SEE IT CAN REQUEST IT BY PRIVATE EMAIL.






Before doing this make sure the transmission and range selector work properly.

HOW WOULD I CHECK THAT, THE RANGE SELECTOR LEVER SEEMS TO MOVE NORMALLY. WHAT ELSE CAN I DO TO TEST THE TRANSMISSION FUNCTION?




THANKS FOR ALL THE HELP, I APPRECIATE ALL THE ADVICE AND THAT NOBODY ACTUALLY LAUGHED AT MY WELDING IDEA.