I took the first official ride (i.e. snow under the skis) last night and noticed that my speedometer/odometer wasn't working.
I had it on the stand earlier this fall & it was working ok. The only thing I did after that was change the belt & reset the trip odometer.
Where do I start looking for the cause? Or should I just replace it?
skutr...
jimfsr has pretty much nailed this topic for the most part, but I'm gonna give my 2 cents, if you are interested...
First of all, how many miles are on your sled? It matters because higher mileage would indicate a greater likelihood of bearing wear. Anyhow...
Ok, for the most part, this is a really, really easy one since you've already verified that the flexible "key" in the speedo drive has broken in 1/2. As stated by other guys on here, this IS a common problem, and it is almost ALWAYS caused by something else that is wrong or going wrong.
Simply put, there are only 2 typical reasons for a broken speedo drive key to occur:
1.) Your speedo cable is stuck in it's housing, leading to the key to shear itself.
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-OR-
2.) Your driveshaft bearing(s) is/are "bad", meaning loose or coming apart!
At first, this leads to the speedo key mis-alignment, which eventually severs the key.
In this potential situation, the breaking of the speedo key is actually a good thing, because it "alerts" you to the potential for disaster if you do not take action very soon. Simply "ignoring" the speedo being inoperative, (like some guys do) is NEVER a good idea.
Glad to see you care about your sled, and your wallet! (2 thumbs up!)
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1.) Ok, let's start simple. I'm talking about the speedo cable itself.
You don't need a drill to spin anything. (I think these guys just like to see their speedos go around.) All you need to do is disconnect the speedo cable at both ends, and twist the cable with your fingers. The cable should spin freely with little to no resistance. If it does not, then it is binding, and you will need to replace it. There, problem solved.
My suggestion with the cable is to pull it from one end (typically the cable itself only comes out through the speedometer end of the sheathing). You will need to pull it and twist it at the same time for it to not get damaged. Never just yank on the cable straight out. It should come right out easily, and there should be no signs of rust or gunk on the cable, that would indicate that it has been binding in its sheathing.
Sometimes you can get away with removing a cable that is bound or binding and clean it with brake/parts cleaner and a rag, lube it with light grease (preferrably speedometer lube, as it doesn't thicken up badly in cold temps like regular grease will) and then re-install it. You will also need to clean the sheathing out as well, which is not as easy. Spray some brake/parts cleaner down the sheathing and then chase it with compressed air. At the driveshaft end in the belly pan, you will see any of the "gunk" that may come out of the cable.
I would inspect your cable sheathing from top to bottom. Many speedo cables are damaged by pinching or crushing of their outer sheathing/housing.
Typical places to look in particular would be where the hood hinges, and where the steering tie rods are, near the bellcrank area just ahead of the motor. Many times the cables are not held in place well, and they end up in "pinch" zones where they get ruined. This often comes from someone that has done service repair work and did not put the cable back in its correct routing path, OR more often, they just did not secure the speedo cable well enough with zip-ties or hold-downs, thereby allowing it to move into "harms way".
If you find a pinched or crushed part of your cable sheathing, or a place where there is heavy corrosion/rust build up, it's time to replace it. Don't try fixing it, it's not worth your time, money, and aggravation.
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2.) Ok, next item at hand...
Let's say the cable checks out. No issues with spinning freely without any binding. That leaves only one "problem" area.
Your driveshaft bearing is worn/mis-aligned, and needs to be replaced. Now, this may or may not be evident at first. First thing to do is look at the obvious visual signs (as one of the guys in this thread has already pointed out).
Tip your sled up on it's right side and LOOK at the driveshaft bearing on the speedo side. If you see anything out of the ordinary, (like the inner bearing seal flopping around on the shaft), or more obvious things, like you see the ball bearings of the bearing (or lack there of) then you have a problem!
Also take a quick look at your chaincase side bearing. Is there any chaincase oil leaking from that area? Oil leakage may (and does often) occur when either side of the driveshaft bearings get bad, due to driveshaft mis-alignment.
If you see obvious problems, then you know what is next. Time to remove the rear suspension, chaincase cover, driveshaft, and bearings. Install new bearings and seals, and re-assemble.
However, if you don't SEE obvious bearing problems, you aren't out of the woods just yet. The next step is to loosen your track all the way up , and take any pressure off of the driveshaft that you can. (It can be a little bit of a pain, but it's best if you get the track completely away from the driveshaft driver cog wheels.) This is necessary so that you can grab a hold of the driveshaft, spin it and move it around (up/down, side to side, etc.), checking for any slop or play in the bearings. There should be none, and the shaft should spin freely with little drag from the chaincase and jackshaft. (Oh yeah, and make sure you have removed your drivebelt fromt the clutches first - lol.)
If the driveshaft spins freely, and has no slop in the bearings, then you are good there. Tighten and re-adjust your track, and you will be good to go.
If not, it's time for bearing replacement and a chaincase service.
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As for "greasing" the bearings... I'm not really sure why people think that the bearings are greaseable. I guess because there is a grease fitting, they just assume that there is a greasable bearing. I can understand the confusion, as I also once believed that the bearings were greasable.
Unfortunately, that is NOT the case. The only reason there is a grease fitting on the lower driveshaft bearing on the speedo drive side is to lube the 90 degree speedo driver and key. What most people do not understand is that ALL of the bearings in these Polaris sleds are fully SEALED "permanently lubricated" units. This means they won't (in theory) lose, nor will they take on grease or any other "contaminants" such as dirt or water. Of course we all know that "theory" doesn't hold 100% true, or we wouldn't have to replace any of the bearings hardly ever if we were able to grease them regularly.
Same holds true for the chaincase... It has oil in it for only one purpose, and that is to lubricate the chain and gears. The oil does NOT flow into the bearings as people think it does. Now, that is not to say that oil does not get into the bearings ever. Just like water, dirt, etc. it does find its way into and often through the lower bearing in the chaincase eventually. This occurs for 2 reasons. #1.) The bearing is worn to the point where its own seals are failing. #2.) The bearing on the opposite side is worn, creating a "cocked" or "mis-alignment of the driveshaft. This causes the lower bearing in the chaincase to also become mis-aligned, and creates the ability for the chaincase oil to leak into the bearing, through the "dust seal" and out onto the ground.
Ok, enough about bearings and seals.
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About getting the little piece of the key out of the end of the driveshaft... If the key is broken and is not flush or sticking out of the shaft where you can just grab it with a pair of needle-nosed pliers, then try this:
One of the easiest ways I've found to remove the key is by taking a very small sharp drill bit, stick it in the end of the shaft, and spin it BY HAND until it binds with the key. Pull it out.
Sometimes a small magnet works also.
I've even gotten keys out with a good, sharp steel pick. (Like what techs use for o-rings and such.)
Finally, if there is a lot of grease in there with the key, the drag and suction of the grease itself may be keeping you from getting the key out easily. Take your compressed air and a blow gun, and blow into the end on a slight angle. More often than not, the key will pop out from the backpressure that is created (along with some grease). It may be a little messy - but so what, that's what rags and parts cleaners are for.
Depending on your sled's driveshaft, some have a little key driver "insert" that are pressed into the end of the shaft. I've had to chisel off the insert and drill them out in rare occassions. Then you remove the broken piece of key, clean up things, pound a new key driver insert into the end of the shaft, and you are ready for re-assembly. That does not pertain to all sleds, and hopefully you won't run into that much of a problem with your speedo drive key removal.
Whatever you do, just be persistant and don't stress over it, you'll get it out of there one way or another!
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I hope this information was able to help you with your speedo problem. Any more questions, feel free to ask.
We're all ears! LOL
