105 hydro problem
 

HI, I just got most of the bugs out of my 105 and took it for a test drive around the yard. It went fine until I was going around (at high speed) and it felt like it suddenly went into neutral, it revs but ''no go'' I experimented with it a little and I found that at low rpm's it would drive but not at any high rpm's and at full speed engagement it felt like it was crunching the gears. I know my trans fluid is low (about 1 1/2'' down from the fill plug) would that be enough to have a no drive symptom or is it more serious then that? There are no leaks any where and the trans don't seem to make any weird noises.

Any help on this would be great, I am going to get some trans fluid tomorrow and top it up and then see if the problem persist.

If you haven't changed the filter and changed the fluid I would just do that instead of adding more to a fluid that you don't know how old or its condition
I don't think that the level is the problem I would guess a filter or a broken drive pin is the culprit

I would guess it's the dowel pin or the drive plate hub assemble. Check that out. Could be catching enough to move it a tad under low idle.

I second that. BTDT

:ThumbsUp:

Ok thanks for that, initial check shows the pin in the drive shaft behind engine looks intact and it is hard to see but the rag joint (Flexible coupling) behind fan looks Ok. I guess I have to tear every thing off the top of the cub to get at every thing? could it be the block off plates in pump busted up? I will start it up and assimilate the problem and see what is spinning and what is not.

Here's a link to the service manual, if you need it.
Info on the hydro starts on pg. 2-30
http://ccmanuals.info/pdf/1x4-5%20Service%20Manual.pdf

1. Check sheer pin at driveshaft/engine

If not problem

2. ensure hytran is full
if not problem

3. Check sheer pin at hydro pump.

If not problem

4. Filter change


if not problem

5. Fluid change.

Ok I checked pin at engine end and it looks intact, a little play there where it has been hammering in the slot but that's all. Coupling looks ok at pump end, did not see any cracks or rips in rag joint and pin appears to be in place. I still need to do filter/oil change but my question is this, while trying to get a feel of what the problem was today, I got it to a no drive situation by lifting the rpm's and with the control lever full forward I was getting knocking back and bouncing of the lever with a crunching gear sound sound, this to me would indicate a problem in the pump I think.

Re-check the drive shaft roll pin at the pump input. Just because you can see the pin in the coupling doesn't mean it's not sheared where it goes through the input shaft. You can't tell just by looking at it.

Look at the rear of the hydro under the seat, and see if the input shaft, where it comes out of the backside of the pump, is turning consistently with the engine speed. If not, then the roll pin is the problem. If it is turning then could be trunnion or (much less likely) pump internal problem.

Second the recommendation to change the fluid and filter. Might be getting some air entrained in the fluid.

If you can hear grinding and crunching noises it sure sounds to me like the hydro pump cashed in it's chips. Used ones are not overly pricey and not a bad job to do. The service manual walks you right through the whole process.Good luck Kelly