# Transmission Failure Symptoms



## Kawinomad62 (Dec 30, 2017)

RESOLVED...please see update below

Hi all, I just finished replacing the main drive shaft and a couple gears in my HS828. The gear box repair seems good. Everything turns smoothly in the gear box. When under power the machine will travel until it comes up against the slightest obstacle. I can raise the tracks off the ground and while they are turning under engine power I can hold the track easily with my hand preventing it from turning. This then causes a sight noise from the transmission. Seems not mechanical but more hydraulic related, almost like a slight whine or like a pump is straining. The noise is subtle though. It seems that by doing this I am overcoming the transmission output thus indicating a problem in the transmission. Also when doing this test if I move the shift lever from forward to reverse and vice versa I notice a subtle movement in the transmission body.

If I turn off the machine and raise the tracks off the ground and the transmission engagement switch set to the released position I can turn the tracks by hand and the gear box shafts turn as expected indicating the gear box is functioning smoothly. 

Does anyone know if this is a symptom of a transmission problem?


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## nwcove (Mar 2, 2015)

Could have air in the system.


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## Kawinomad62 (Dec 30, 2017)

Thanks...i've tried the bleed procedure with the trans in place. Snowblower standing on its nose. I didn't observe any air bubbles. No luck in solving the problem unfortunately.


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## JnC (Feb 21, 2014)

For the system to be properly bled you need the transmission off the machine and on a level bench, seeing that you have already tried to bleed it with it still being on the machine with no avail I'd say just spend the time to take it off of the unit, drain all the old fluid, refill with new HST fluid and do the air bleed. These HSTs are almost bullet proof, I suspect that an air bubble has gotten caught in the pump and is causing this issue.


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## JimmyD (Nov 20, 2016)

Kawinomad62 said:


> Thanks...i've tried the bleed procedure with the trans in place. Snowblower standing on its nose. I didn't observe any air bubbles. No luck in solving the problem unfortunately.


Did you tip the blower past vertical so the drain plug is the highest point of the transmission? Also, did you turn the pulley by hand to work any air out?

Did you unbolt the reservoir, tilt it upright (with blower still vertical), and fill the transmission through it? This is the only way you can be sure you're purging air from the system as it's filling up... just filling through the drain hole isn't enough. You'll need to cap off the transmission drain while fluid is dripping out so you don't accidentally trap air inside; a second set of hands works well for this. 

If you're doing the work in the cold, you can try heating the bottle of fluid first in a pot of hot water (just be careful that you don't scald yourself if you spill any!). You should be able to reuse the new fluid you just put in the unit. Make sure it's free of any dirt or debris and put it back in the bottle. Having the fluid be thin helps immensely in purging air bubbles.

If you aren't able to get it to work this way, you'll have to do what JnC suggested and pull the tranny. It's not a lot more work if you have the machine up on its bucket anyway, and it lets you take a look at the sub transmission while you're there._ edit: I just realized you had done this already_

If you're 100% sure that you've replaced the fluid properly there may be an issue inside the HST unit. It's *very* unlikely, but they can fail.


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## Kawinomad62 (Dec 30, 2017)

Thanks for the response. Yes, I did what you suggested. Had the drain plug as the highest point by tipping the machine on its nose. I repositioned the reservoir as you suggested. and also turned the pulley with my fingers.. I haven't changed all the fluid just topped it off through the reservoir. I'm trying desperately not to have to remove the tranny ...lol. I did open the drain bolt however. Before I get it fully removed fluid starts pouring out of it, indicating plenty of fluid. I know bleeding my motorcycles brakes can be a pain, so I think I will give that another try.

Thanks again....


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## Kawinomad62 (Dec 30, 2017)

Thanks JNC...I will follow up and report back.


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## Kawinomad62 (Dec 30, 2017)

I may have introduced air by working on the gear box while the blower was standing on its nose and the reservoir in its normal mounted position. The reservoir sat on its side with low fluid for several days likely exposing the hole! I certainly would have introduced air when I later removed the drain plug for a look.

Quick question: The bleed procedure on the forum mentions rotating the cross shaft counter clockwise in the initial steps. I guess counter clockwise depends on whether you are viewing the trans from one side or the other. Would that shaft rotation for that initial bleed step be the same as when the machine is travelling in reverse or forward? Or in other words, would the shaft rotation be in the opposite direction versus when it rotates when turning the pulley by hand? I'm trying to determine if I need to have the pump turning in both directions for the bleed procedure? I hope this makes sense....thanks...


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## drmerdp (Feb 9, 2014)

Removing the engine and bed plate or the bucket to gain access to the transmission pulley is easier them removing the transmission.

I’ve done a bunch of hydros, just not an HS transmission, but the process is pretty much the same.

Start with the speed lever in neutral and the engagement lever on the trans itself in the “free” position. Then slowly work through the speed lever through it’s range forward and backwards a few times and look for bubbles through the reservoir.

Then switch the transmission lever to “engaged”. And repeat the same process. 

I think Honda talks about strapping the machine in a fixed position on a semi slick surface with the drive engaged to further bleed the system if necessary.


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## JimmyD (Nov 20, 2016)

drmerdp said:


> I think Honda talks about strapping the machine in a fixed position on a semi slick surface with the drive engaged to further bleed the system if necessary.


Yes, this is part of the PDI procedure when new. They put the machine on a piece of plywood, facing a wall with a tire in front of the bucket to prevent scratching.


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## Kawinomad62 (Dec 30, 2017)

Resolved....

From my initial post....

Hi all, I just finished replacing the main drive shaft and a couple gears in my HS828. The gear box repair seems good. Everything turns smoothly in the gear box. When under power the machine will travel until it comes up against the slightest obstacle. I can raise the tracks off the ground and while they are turning under engine power I can hold the track easily with my hand preventing it from turning. This then causes a sight noise from the transmission. Seems not mechanical but more hydraulic related, almost like a slight whine or like a pump is straining. The noise is subtle though. It seems that by doing this I am overcoming the transmission output thus indicating a problem in the transmission. Also when doing this test if I move the shift lever from forward to reverse and vice versa I notice a subtle movement in the transmission body.

If I turn off the machine and raise the tracks off the ground and the transmission engagement switch set to the released position I can turn the tracks by hand and the gear box shafts turn as expected indicating the gear box is functioning smoothly. 

Resolution.......

This problem was not the transmission at all. It was effectively the big gear separating from the pin on the drive shaft. The gear was still able to turn while the pin was not engaged in the gear slot due to tight clearances and friction. It actually caused a scoring mark on the gear box cover indicating the gear was riding against the cover.

1) You can determine whether this is the problem by raising the machine off the ground and observe the transmission shaft and drive shaft rotation. If the transmission shaft is turning entering the gear box and the drive shaft is not turning exiting the gear box then the problem is in the gear box. When my machine was raised off the ground the tracks turned under engine power. Both the transmission shaft and drive shaft turned as expected. I could then easily hold the track with my hands and prevent it from turning (careful with your fingers here!!!) . While doing this I observed the transmission shaft still turning indicating the trans its OK but the drive shaft not turning. The problem is therefore not the transmission but back inside the gearbox.

Inside the gearbox if everything looks good, transmission and intermediate (short)shaft splines are not damaged and gear splines and teeth are not damaged, then you have this problem. 

To avoid this problem make sure the gear freely rests on the drive shaft pin, sitting deep in the gear slot. The pin should sit flush with the surface of the gear.

2) My replacement Honda gear was very tight on shaft. I had to actually hammer it in place. This was a mistake. If it is this tight and it happens to move away from the pin it will not easily go back in position. initially I hammered the crap out of it to get it to sit on the pin and when I turned the shaft it with my hand the gear separated from the pin easily.

3) I took my dremel and honed out the center of my gear to allow it to ride smoothly over the shaft (in retrospect I should have returned the new gear to Honda. By the way, my old gear slid over the drive shaft with ease). Do this in small steps checking for fit repeatedly. You don't want it to be sloppy.

4) I used the dremel to clean up the slot in the gear. Be careful you only want to remove any burrs that might exist. Do not reshape the slot greatly. Work lightly and test fit often. Remove any grease or grime that may have accumulated in the slot form previous installations.

5) Next be sure that the gear slot and pin mesh together easily. In my case I took the shaft to the bench grinder and just lightly touched the ends of the pin to the grinder wheel. Then test fit. Make sure to rotate the gear 180 degrees and test fit again. In my case I had to take another bit off the pin so that it fit perfectly regardless of the gear orientation. The goal is to ensure there is no obstruction whatsoever and the gear and pin freely fall in place.

6) During reassemble be absolutely careful that you don't disconnect the gear from the driveshaft pin. The drive shaft can move freely left and right through the gear box until the tracks are reinstalled. This movement can potentially cause the gear to move off the pin.

7) Reinstall everything carefully.

Other observations

1) There are 4 springs from **** involved that like to disconnect from their pull cables and spring holders during the reassembly. It helps to tie the left handlebar lever down to keep some tension on the springs.

2) The "cable holder" has to be removed in order to remove the side cover to access the gearbox. This then takes tension off the springs. After cable holder removal, and with the cables still installed on the holder, I tied the holder back with a bungee but still struggled with the springs. It helps to remove the front plastic cover (with the HONDA decal on it) so that you can get your hand on the cable holder properly in order to hold it in the correct position during reassembly. This avoids stripping the bolt holes!!! Don't ask how I know this!

3) I bought a pair of long reach needle nose pliers with a bent nose. This tool helped deal with the relentless springs.

4) If you stand the blower on its nose to do this work, ensure you remove and reposition the transmission fluid reservoir to keep it in it's upright position. This may avoid the potential problem of allowing air to enter the trans fluid.

Thanks for all the input folks....I hope this helps...


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