# Polar Blast slow speed drive issue



## markgm

I have a 6 year old Troy-Bilt Polar Blast that has had drive issues for pretty much as long as I’ve had it. It works well at higher speeds, but at the slowest speed it will sometimes move forward, stop, and then start moving backwards. It moves backwards at a pretty good speed too, faster than the slowest reverse speed. I’ve adjusted the drive speed cable as suggested in the manual, but I still have the issue. You can see in the video that something is speed mechanism moves on its own when this happens. Yesterday while using it I noticed that if I held the drive handle down halfway, it didn’t back up. With a 45” width, I can really use the slowest speed (which was a bit faster than what you see in the video, I adjusted the speed cable right before taking this video). Any thoughts?


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## orangputeh

with the belt cover off, does the drive belt turn when it is in neutral? 

when this sort of thing happens with my machine , it usually needs an adjustment which you mentioned you already have done.

is there any grease or oil on the pulley wheel? looks like the belt is slipping. do not have any experience with Toros but we will have other members chiming in soon.


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## jonnied12

Tip it up on the bucket. Remove the bottom pan and check the spring and pin noted in the attached photo.
Also apply a thin film of Anti-Seize on the hex shaft.


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## RedOctobyr

Definitely check the spring that was suggested. In your video, you can see the gear-selection cable suddenly lose tension, and go loose, as the machine starts to back up on its own. That makes me think that perhaps that spring is not doing its job, and is letting the rubber wheel slide where it wants, along that shaft. 

The ground speed is determined by the location of that rubber wheel. Tip the machine up, remove the bottom cover (follow your manual; this blower must be a *beast*, please don't hurt yourself, or damage the machine). Watch the rubber wheel's position as you move the gear-selection lever. 

For slow-forward, the rubber wheel will be a little off-center of the aluminum disk, to one side (let's assume to the right, for discussion). For fast-forward, the rubber wheel moves closer to the outside edge of the aluminum disk, on that same side (to the right). For slow-reverse, the rubber wheel is positioned a little off-center, but in the other direction (to the left). This makes the rubber wheel turn backwards. 

It seems like, when you select slow-forward, the rubber wheel is close enough to the middle of the aluminum disk that it's able to slide over towards the wrong side of the aluminum disk (moving from the right-side, to the left), and suddenly you're going backwards. The spring that was pointed out should help prevent this, and always maintain tension on the speed-selection cable. 

When you're in a faster forward speed, you're already further away from the center of the aluminum disk, and the rubber wheel is more securely in the forward range, so it's probably less likely to suddenly change directions. 

I wouldn't be surprised if this spring broke, or came unhooked somehow. Hopefully it will be a straightforward and inexpensive fix.


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## markgm

It is a beast (not a blast) flipping this thing on its front! I took off the bottom panel, and I couldn’t see anything out of the ordinary. I added some grease, but it didn’t seem to do anything. The spring looks to be in good condition. After adjusting the speed nut (1 forward is now a snails pace), the unit seems to reverse slowly, and then go back quickly. At least it appears to be consistent with moving the friction disc. You can see the cable pushed up in the video, just as it was doing in my original video when it would reverse itself. The plot thickens! 

I did loosen the cable on the handle to engage the drive mechanism. I feel like it was much too tight, and I could probably loosen it some more. The friction disc seems like it’s about halfway worn away when compared to a new one (I have spare parts for this thing as it seems to eat anything remotely consumable). 

Insides of the unit:






After adjustments:




 
In the attached photos, the piece circled with the big orange circle has some play, moving maybe half an inch forward and backwards within the smaller circle. 

I really wish they didn’t have such big gaps between 1 and 2!


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## RedOctobyr

The play between the two parts noted in the circled picture looks intentional, to me. With the way those parts tilt and slide, there likely *needs* to be some play in that direction, or else they might bind up. 

It was tough to see what gears you were using while going forward in the 2nd video. But I saw that you started in, say, reverse 1, and then the cable went slack, and it sped up, like to reverse 2. 

I think either: 
- that spring is weak, and needs to be replaced
- *possibly*, it has something to do with the worn rubber disk. If it's a lot wider now than a new disk, *maybe* that's causing something weird, and it's being pushed to the side too hard, and overcoming what the spring can provide. How different do the 2 disks look? 

But my guess is it's spring-related. 

As a test, can you maybe attach a "helper" spring to that lever? Just an extension spring, not a torsion spring (the style that's on there now)? Something to help hold the lever in the direction that the existing torsion spring is trying to achieve, so the lever stays pulling against the cable. 

You could also try adding a thin layer of lubrication to the hex shaft that the rubber disk slides on, in case it's binding, and that is somehow causing strange behavior. I typically use grease, not oil. You don't want something that will fling off of the spinning hex shaft, and make the rubber wheel slippery. You need to maintain that friction. You might also just see if anything on the spring looks like it's binding somehow (seems unlikely), and possibly sapping some of the spring's force. 

Also, as an aside, the gears selection locations are slightly arbitrary, if you want to call it that. If you feel strongly that you'd like a gear somewhere between 1 and 2, you could try cutting another groove into the control panel, to give an additional selection location for the lever, kind of a gear 1.5. This is an expensive thing to undo, of course; I'm sure that control panel is expensive. But just something to be aware of.


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## markgm

Thanks for your suggestions! The existing friction wheel doesn't look noticeably wider than the new one I have on hand. What is the purpose of the shift rod spring, is it to keep the friction wheel in place by fighting against the shift rod cable? 

I assume it doesn't matter which hole the shift cable is in? I think it's sad there isn't consistency in the manual.


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## RedOctobyr

When you say "the purpose of the shift rod spring", you mean the torsion spring circled in the picture in post #3? 

It is there to always ensure there is tension on the speed-selector cable. I'm used to that speed-selection device being a rod, on my machines, not a cable. With using a rigid rod, it can fight being pulled (like a cable) *or* pushed (unlike a cable). So mine doesn't need the torsion spring, as the rod serves that function, of being able to push or pull. 

For the purposes of your issue, at least, no, it doesn't matter which hole the cable is going to, in the speed-selection lever at the bottom of the machine. The problem is that the cable is somehow going loose, which has nothing to do with the hole selection.


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## markgm

Thanks, yes, I was referring to the torsion spring. I was looking at another video that hat a rod instead of a cable and thought "if it used a rod, it wouldn't be having this problem!"


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## jonnied12

markgm, did you follow the directions in the owners manual to adgust your shifter? See attached.


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## jtclays

144


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## vmax29

I had a TroyBilt with same symptoms and finally decided to change the friction disc. When I had it apart I compared the two rubber drive wheels side by side. The old one was worn but not by much. The new disc was installed and it solved the issue. 

Also +1 on the suggestion to use a thick grease very sparingly. Any lubricant on that disc will cause trouble.


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## markgm

I guess I will go ahead and change the friction wheel this spring, though it appears to be in good shape, with no obvious convex or concave areas. Before I do I'll check if there is any play in the bearings. I might also see if I can convert the shifting mechanism from a cable to a rod; it seems like it wouldn't be too difficult to do. The really strange thing is looks like the friction wheel itself was discontinued, which doubles the price of replacing this part. 

918-04178 - Entire friction wheel assembly
718-04034 - Friction wheel


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