Brand new out of the box 2012 splined driveshaft way out of true!!!

[paulharris]

well, for those thinking of putting a 2011-2012 shaft in their 2013 with belt drive you might want to check your shaft for runout. I just recieved a brand spanking new 2012 shaft, took it out of the box, put it on a jig that i made to spin it and make sure it was true.....i was shocked at what i saw. the splined end that the belt drive sprocket goes on is way out of true. this is a brand new shaft. i estimate it at least .015" out of true. it is clearly visible with your eye. it is a wobble at the end and you can see it all the way up to where its welded on the shaft. it is un-usable in the 2013 because that runout will magnify itself on the belt drive pulley creating a "loose-tight" wobble and thus eat up the belt.

so clearly the tolerances on these welded shafts are not very tight. this really makes me mad that the quality control is this sloppy. perhaps some are ok, but even the smallest amount of runout will surely make big problems for the belt drive.

See pics attached. you can see where they cylindrical grind the splined end and the parts where the grinding wheel never touched because of the wobble. clearly their jigs are not accurate enough to produce a precision part.

This really makes me think that the best solution may be a standard hex shaft machined out for this sled.....there will be NO RUNOUT because there is no welding, no gluing, no 3 piece assembly. it would be a perfectly straight shaft.

Is polaris building tractor parts here? now i have 2 POS driveshafts. disgust

 

[winter brew]

Nothing unusual...chuck it up in a lathe and true the driver surface to the bearings. The couple I did "back in the day" were more like 0.10" at the driver surface.
I'm surprised it is with .015....I've seen cranks farther out than that.

 

[paulharris]

Nothing unusual...chuck it up in a lathe and true the driver surface to the bearings. The couple I did "back in the day" were more like 0.10" at the driver surface.
I'm surprised it is with .015....I've seen cranks farther out than that.

won't do any good, this is not just a one dimensional "offset" out of true that i am talking about. i wish it was. the splined end is literally welded crooked on the shaft. the driver surface is the least of my concerns, you can true them all day long but it still won't make the wobble on the end go away which will ultimately lead to a very wobbly belt drive sprocket.

 

[Deucer]

Check your run-out on the 13. I bet it is that much out also. I cannot see pressing a hub into a hollow tube and putting glue on it to be any more accurate.

D

 

[Coffee]

Have you ever tried to weld three pices of metal together and keep it concentric?


I don't care how accurate you welding fixtures are. After you start to stack tolerances from the fixtures for slip fit and the movement from heating of welding .015 is really good IMO.

 

[paulharris]

Have you ever tried to weld three pices of metal together and keep it concentric?


I don't care how accurate you welding fixtures are. After you start to stack tolerances from the fixtures for slip fit and the movement from heating of welding .015 is really good IMO.

My whole point is that if this is as good as they can do with the tolerances then these driveshafts are simply not compatible with this belt drive system....period. with a non-tensioned belt drive system like this even the smallest amount of runout is not going to work. I am being conservative with the .015" number it is probably more....i can tell you it is very obvious when you spin it. and that .015" magnified out on the edge of a 4" belt drive pulley will be a lot of wobble. guess what happens when you hit the brake or power under load in that "loose" spot? stripped belt cogs.

i am sure they vary greatly in how much runout they have. i am sure some will be nice and true. just saying that this one i bought is brand new and its unusable for the belt drive IMO. Luck of the draw whether you have a good one or a bad one.

 

[Coffee]

I'm not saying that it was a good design at all. I had my thought about this last spring and didn't think it was a good design at all. Now we find about the POS drive shaft good luck to all the new PRO RMK owners. If it was me I would become good friends with a machinist.

I've looked into it and the only part number I haven't found to make a solid hex shaft one is the tool to cut the spline and that is only because I don't have one in front of me to measure and find the right tool.

I think that is going to be the most sound way around this problem.

 

[Dam Dave]

Have you ever tried to weld three pices of metal together and keep it concentric?


I don't care how accurate you welding fixtures are. After you start to stack tolerances from the fixtures for slip fit and the movement from heating of welding .015 is really good IMO.

Sure, you weld all the raw un machined pieces together then do all the machining..........its done everyday

 

[paulharris]

Sure, you weld all the raw un machined pieces together then do all the machining..........its done everyday

Talked to Mark at CMX. he does not have a replacement driveshaft for the 2013 but he does have a complete bolt on belt drive/driveshaft combo with D/R. very nice setup but not cheap ($2500). he was pretty much laughing his *** off at this whole driveshaft/belt drive design with no tensioner that polaris engineered. the more i look at this system, the more i realize how big of a fail it is. you simply can not have a non-tensioned belt drive system with sloppy tolerances like polaris is using on these parts. cast sprockets are the first fail because they are not precision enough. and glued 3 piece driveshafts with runout (lots of runout when they snap) on the drive sprocket end are the second fail. i'm sure there are many more

 

[Hawkster]

Hey your a little hard on these guys , don't you know that they've come out with a completely disposable machine . They've hit the big time soon to be sold at your local Wal-Mart along side the inflatable santa clause for the front yard . ..............Protowboy ............. ok now I'm done .

 

[mountainhorse]

From another thread... with respect...

Good catch on the 2012 shaft that you bought.

I agree that something with a lot of runout will not bode well for the belt drive.

It is good that you measured your run-out.

I know you checked the One shaft that you ordered... could be a mfg defect... could be something else like mishandling... this could also be from the bearings

With respect, not trying to be a smart-azz... your sample size (one) and the conclusion drawn from that sample may not be an indication of fitness of the steel shaft for use in the QD system.

Since your other post, I went out to the shop and grabbed the 5 different hydroformed driveshafts I have... 2005, 2006, 2008, 2010 and 2011 RUSH shaft and headed for my neighbors shop. All shafts have been used.

Found a max of 0.012" at the sprocket-spline-register run-out on those... the worst one was in a wreck.

The max on the other shafts was 0.004".

Best was 0.001" (the 2011 RMK) Using my neighbors Starrett v-blocks and dial indicator.

I don't believe that it is steel shaft construction method...but you do seem to have a wobbly shaft.

What is the max runout tolerance in the belt drive??? I don't know... but not much.

Chain drive RMK's don't have much tolerance for wobble either.

I don't see an inherent problem with the steel drive shaft and compatibility with the 2013 QD.... But I also have not sampled different new shafts from the factory.

 

[mountainhorse]

Also... after looking at the machining marks on your splines (or lack there of) like you pointed out... it seems that the shaft is defective and should be returned. Blatantly obvious that that shaft is out of true just by looking at it... Not typical for these drive shafts.

I would not run that shaft in a chaindrive either.

That shaft is definately out of true.

As Dam Dave pointed out... these receive final true after assembly.

ONE SIDE

THE OTHER SIDE

 

[4Z]

Micro Belmont can make hex shaft to what ever dimension you want. Then a set of Robby's CNC' drivers and you are back in biz. All the shafts MB has made for me back in the day worked very well.

 

[paulharris]

Also... after looking at the machining marks on your splines (or lack there of) like you pointed out... it seems that the shaft is defective and should be returned. Blatantly obvious that that shaft is out of true just by looking at it... Not typical for these drive shafts.

I would not run that shaft in a chaindrive either.

That shaft is definately out of true.

As Dam Dave pointed out... these receive final true after assembly.

ONE SIDE

THE OTHER SIDE

Yes, this is why i took these close up pics so you can clearly see the uneven grinding on the splined end indicating the wobble.

this is the 3rd shaft that i have checked. as for this new shaft being mishandled that is out of the question. there is no sign of shipping damage on this shaft i inspected it very closely everywhere. and unless it was dropped from a ridiculous height its not going to bend the end of this shaft. Sadly, this is the kind of quality control (lack of) that polaris has. and i am pretty sure its not the only one out there like this. This shaft had to be spun to true the drivers and had to be spun to grind the splined end and it still made it out the front door of whoever builds these for polaris. I do believe that a chain drive is more forgiving to runout, but i don't think i would run this on a chaincase either.

As for the other shafts: the first one was a used 2011 shaft-it had runout on the opposite end (clutch side) but the splined side was pretty good. in hindsight i wish i would have kept this one-better to have some runout on the clutch side rather than the drive side.

oddly, the best shaft i have measured is a used 2005 900 rmk shaft. it is very true on the drive side and slightly out of true on the clutch side. This one is good to go for the belt drive IMO.

I believe that the only way to guarantee a perfectly true shaft with zero runout for the belt drive is to go the hex shaft route. otherwise its the luck of the draw whether you have a precision stock shaft or not. I spoke with micro belmont and he said he can make them no problem. Problem is that no one knows what polaris is going to come up with for a warranty/recall fix, if anything.

 

[500 CID]

Just finished checking 2 new 2012 driveshafts, total indicated runout on the worst one was .004 and the best was .0015. These were checked in precision V blocks resting on the bearing surface of the shaft, not the bearing itself with a Mitutoyo indicator.

 

[paulharris]

Just finished checking 2 new 2012 driveshafts, total indicated runout on the worst one was .004 and the best was .0015. These were checked in precision V blocks resting on the bearing surface of the shaft, not the bearing itself with a Mitutoyo indicator.

why wouldn't you spin it with bearings on the shaft like when mounted in the sled? i have found is that the outside of the bearing will move and follow the wobble if the ends are out of true making it easy to see. if this was simply an offset then the v-blocks would work fine, but what i am seeing is a wobble, not an offset. a v-block sitting directly on the shaft will hide this. can you fixture it so the bearings are sitting in your v-blocks?

also, just to clarify....i am NOT talking about runout at the drivers while spinning the shaft with this thread. i think some are confusing it for that. the drivers are running plenty true on all the ones i have checked. I am talking about runout (wobble) on the outer edge of the splined drive end in relation to the the chaincase bearing in the factory location on the shaft. the reason this is so critical is because this will have a direct impact on your belt drive tension. in order to measure this runout with a dial indicator a sleeve or a collar needs to be put over the splines.

 

[turboless terry]

Talked to Mark at CMX. he does not have a replacement driveshaft for the 2013 but he does have a complete bolt on belt drive/driveshaft combo with D/R. very nice setup but not cheap ($2500). he was pretty much laughing his *** off at this whole driveshaft/belt drive design with no tensioner that polaris engineered. the more i look at this system, the more i realize how big of a fail it is. you simply can not have a non-tensioned belt drive system with sloppy tolerances like polaris is using on these parts. cast sprockets are the first fail because they are not precision enough. and glued 3 piece driveshafts with runout (lots of runout when they snap) on the drive sprocket end are the second fail. i'm sure there are many more

That's funny since i ran a cmx belt drive, with no tensioner, for over 4000 miles and it wasn't near as tight as the polaris belt.

 

[winter brew]

I misinterpreted your original post....was thinking driver surface.
Now add in the variance in the cast lower pulley. I havnt got the dial indicator out but watching the pulley spin at low speed it reminded me more of a camshaft. Whether its the shaft or the pulley I dont know. I dont know enough about these belts to know how precise their pulleys need to be, but I would think it quite forgiving as long as it stays within proper tension parameters.

 

[Hawkster]

That's funny since i ran a cmx belt drive, with no tensioner, for over 4000 miles and it wasn't near as tight as the polaris belt.

I thought all CMXs' had a tensioner ??

 

[turboless terry]

Mine came with a tensioner but didn't have to run it with the ratio I ran. I would be more worried about a bearing than the belt on the polaris.