# Honda HSS Service Bulletin: Intermittent Ground Speed Slowing



## [email protected] (Nov 21, 2011)

Cavitation can cause air to sometimes enter the HST pressure circuit under the described conditions. This is rare, but can happen. 
What's the fix? For customer units, an expansion tank is fitted that will prevent air from getting into the circuit. 

Units built _after_ the affected range are fitted with an internal baffle plate that does the same thing. It would be costly to fit these plates on units already in service, so that's why a fix using a easy-to-install tank is offered for those units with the problem. 

*Gotta stress to everyone, you DON'T need a tank, unless your HSS is in the affected range AND you're having speed problems during transport. *


----------



## Lake Effect (Jun 13, 2017)

Had this done this past summer and it resolved the speed issue I was having last winter. Thanks for keeping everyone up to date, Robert!


----------



## uwelk (Jan 6, 2016)

I was wondering if anyone that has had this problem could explain it better. I have a HSS928 that fits in this affected group. The speeds have never been very fast particularly in reverse. I have been a bit disappointed in the slow speed but have never experienced intermittent speed issues. I assumed that the slower speeds were normal and just a limitation on the machine. Now I am wondering if I should have this fix done. An experienced description would be helpful.

Thanks


----------



## grabber (Nov 28, 2015)

check the speed yourself with mesurement. How many seconds does it takes to travel 30ft ?
Mine takes twice the normal speed stated in the shop manual. Will gladely bring it to Honda to have it fixed. The speed is ok at first, but after 3 or 4 minutes of working with it, backward, forward.... the speed because very slow.
According to the specs i have here, the HSS928 shouldnt take more than 10 seconds to travel 30ft. Anything longuer than that... you have speed problem. In reverse it shouldnt take more than 15 seconds. This is for the track model by the way.



uwelk said:


> I was wondering if anyone that has had this problem could explain it better. I have a HSS928 that fits in this affected group. The speeds have never been very fast particularly in reverse. I have been a bit disappointed in the slow speed but have never experienced intermittent speed issues. I assumed that the slower speeds were normal and just a limitation on the machine. Now I am wondering if I should have this fix done. An experienced description would be helpful.
> 
> Thanks


----------



## tabora (Mar 1, 2017)

I just noticed an *Oil Tank* diagram on the Honda Power Equipment Parts site for the HSS1332 that I don't remember being there before... Looks like the one pictured in the upper left may be the one that gets added to the affected machines.


----------



## csonni (Dec 26, 2017)

Yay. My HSS1332 begins with 1009.....I’m safe I suppose.


----------



## feh (Dec 16, 2016)

My 1332 is 4926 and falls in the recall range, but I don’t experience the speed issues as described (11 hours on it so far). Fingers crossed.


----------



## jrom (Jan 10, 2014)

Thanks for the heads-up.

I'm not having any trans problems (Honda replaced mine...[looking up]...a year ago yesterday), and I've had plenty of snow since then (Put 30 hours on the new trans), but I only have until Nov 16, 2018 for any warranty claims. If the snow keeps up (170" since Dec 8), I probably have only 2 more months of snow for any free problem repairs. Everything has been great on it though.

Only searching hondapartsnation.com all the items on the order page comes to just under $113 not including shipping.

Hmmmm. I'm going to do some timing tests and side-by-side comparison to my '91 HS828.



tabora said:


> I just noticed an *Oil Tank* diagram on the Honda Power Equipment Parts site for the HSS1332 that I don't remember being there before... Looks like the one pictured in the upper left may be the one that gets added to the affected machines.


----------



## Lake Effect (Jun 13, 2017)

jrom said:


> Thanks for the heads-up.
> 
> I'm not having any trans problems (Honda replaced mine...[looking up]...a year ago yesterday), and I've had plenty of snow since then (Put 30 hours on the new trans), but I only have until Nov 16, 2018 for any warranty claims. If the snow keeps up (170" since Dec 8), I probably have only 2 more months of snow for any free problem repairs. Everything has been great on it though.
> 
> ...


You may have an updated transmission(current production) that has internal baffles, which eliminates the need for the reservoir.


----------



## jrom (Jan 10, 2014)

That would be good. I may ask my dealer if they know. Thanks.



Lake Effect said:


> You may have an updated transmission(current production) that has internal baffles, which eliminates the need for the reservoir.


----------



## tabora (Mar 1, 2017)

Lake Effect said:


> Had this done this past summer and it resolved the speed issue I was having last winter. Thanks for keeping everyone up to date, Robert!


Can you post photos of the installed oil tank and the connection to the transmission so we can see exactly how/where it mounts? Thanks!


----------



## Miles (Sep 16, 2016)

My question is this: If this is design flaw due to the shape of the chamber where cavitation is taking place, won't this affect all the early models with that shape of chamber and no baffle? If an early machine is not being used commercially for long periods of time, the flaw may not show. But doesn't it still exist and shouldn't all the machines be fixed? I certainly want mine fixed and I plan on bringing it in at the end of the season. If my circumstances change and I move to a heavy snow area, I don't want to worry about having speed problems. Maybe I am missing something here. Do you think that a warranty fix is justified?


----------



## Lake Effect (Jun 13, 2017)

tabora said:


> Can you post photos of the installed oil tank and the connection to the transmission so we can see exactly how/where it mounts? Thanks!


Post #84 http://www.snowblowerforum.com/forum/honda-snowblowers/102138-ground-speed-9.html


----------



## Lake Effect (Jun 13, 2017)

Miles said:


> My question is this: If this is design flaw due to the shape of the chamber where cavitation is taking place, won't this affect all the early models with that shape of chamber and no baffle? If an early machine is not being used commercially for long periods of time, the flaw may not show. But doesn't it still exist and shouldn't all the machines be fixed? I certainly want mine fixed and I plan on bringing it in at the end of the season. If my circumstances change and I move to a heavy snow area, I don't want to worry about having speed problems. Maybe I am missing something here. Do you think that a warranty fix is justified?


The internal baffle on the new production will prevent the transmission fluid from sloshing as much, preventing cavitation. Early models without baffles allow air into the system(cavitation). The bulletin addresses this by keeping the transmission housing topped off with fluid all the time using a reservoir. The external housing shape is probably the same or similiar. Older models had a small reservoir, the HSS models did away with it.


----------



## drmerdp (Feb 9, 2014)

Here’s a top view with the tank on the left.


----------



## grabber (Nov 28, 2015)

Had my Hss1332 repaired this week. Did test it a little and the speed is good. Reverse is good too. Havent got ennough snow yet to test it good, but im positive the problem is solved.
Speed problem is something of the past now.


----------



## gasgas (Jan 20, 2020)

Lake Effect said:


> Had this done this past summer and it resolved the speed issue I was having last winter. Thanks for keeping everyone up to date, Robert!


What was the cost?


----------



## tabora (Mar 1, 2017)

gasgas said:


> What was the cost?


It was free under warranty if done within 3 years of the purchase. It only applied to the early HSS machines - see serial number ranges in Post 1 in this thread: https://www.snowblowerforum.com/forum/1439714-post1.html
Later machines are fitted with an internal baffle plate that does the same thing.


----------



## MLF149 (Dec 21, 2020)

Interestingly, according to the parts diagrams, there was no transmission change at the ....6875 serial.


ef NoPart NumberDescriptionSerial FromSerial ToQty00120001-V45-305TRANSMISSION ASSY.10000011005593Add to Wishlist00120001-V45-315TRANSMISSION ASSY.10055941016589Add to Wishlist00120001-V45-325TRANSMISSION ASSY.10165909999999

I just bought my unit last week, dealer had tons of the 2019 left over. Mine has the middle transmission, but when you look at the detailed transmission diagram (internals) it doesn't show any changes from 1000001 to 9999999. Something doesn't add up. You would expect a change to the internals at 6875 according to the TSB. I noticed the price of older parts is way higher. Ex. the middle transmission is hundreds of $ more than current. Wonder if older parts bolt straight up. 

(I know this is an old topic; just found it interesting)


----------



## Miles (Sep 16, 2016)

They added baffles in the tank to prevent cavitation.


----------



## tabora (Mar 1, 2017)

MLF149 said:


> Interestingly, according to the parts diagrams, there was no transmission change at the ....6875 serial.
> 
> 
> ef NoPart NumberDescriptionSerial FromSerial ToQty00120001-V45-305TRANSMISSION ASSY.10000011005593Add to Wishlist00120001-V45-315TRANSMISSION ASSY.10055941016589Add to Wishlist00120001-V45-325TRANSMISSION ASSY.10165909999999
> ...


It's that first part number that was problematic. I had the external tank added and my S/N is SAFA-1004819. I wonder what the second update was?


----------



## Sunnysnow (Dec 29, 2021)

[email protected] said:


> Cavitation can cause air to sometimes enter the HST pressure circuit under the described conditions. This is rare, but can happen.
> What's the fix? For customer units, an expansion tank is fitted that will prevent air from getting into the circuit.
> 
> Units built _after_ the affected range are fitted with an internal baffle plate that does the same thing. It would be costly to fit these plates on units already in service, so that's why a fix using a easy-to-install tank is offered for those units with the problem.
> ...


Has anyone install this kit themselves? See,s simple. Just not sure if it comes with instruction. The oil tank just gets mounted on the side panel…. Thanks


----------



## tabora (Mar 1, 2017)

Sunnysnow said:


> Has anyone install this kit themselves?


@Toon is getting ready to do so... Stay tooned! (Couldn't resist...)








HSS928 SST oil expansion kit


Hi Folks I have read here on this site that there is an external oil expansion kit that was installed on the early HSS928 models. Does any one have a part number and perhaps pictures of the way this kit was installed. I think I would like to upgrade my 2016 machine. Thanks




www.snowblowerforum.com


----------



## Toon (May 11, 2021)

tabora said:


> @Toon is getting ready to do so... Stay tooned! (Couldn't resist...)
> 
> 
> 
> ...


Yes I am but the parts have not yet arrived, although they have been shipped. Still haven't got an answer from Honda as to how full the transmission has to be so I guess I'll fill it up to the top when the parts arrive and I do the install.


----------

