Jack Shaft issues?

Sleddogg

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Dec 5, 2007

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Dayton, WY

• Mar 3, 2015

• #1

I've heard of several Jackshaft issues around and they are on backorder for 2-3 weeks. Any clue what causing it? Anyone else have issue?
Exhaust side shaft has worn down a lot on my 15 Pro, bearing seems surprisingly fine!
500 miles on sled.
Attached pics are both sides of shaft for comparison.

 

Indy_500

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Greenville, WI

• Mar 3, 2015

• #2

Poor machining tolerances.

 

L

LoudHandle

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Valdez, AK

• Mar 3, 2015

• #3

That failure mode was very common on the '13's also. It is caused by one of two things; running it with the fastener loose or is due to the stack height of the bearing, brake disk hub, and the QD sprocket being the same height or less than the shaft stub. The first will lead to the later on susequent installs, unless all the worn parts are replaced. So when the fastner is torqued the washer bottoms on the shaft rather than the sprocket hub. As the bearing is a slip fit on that side it must be pinched between the Jack shaft shoulder and the stack of brake disk hub and sprocket hub, if not pinched it just spins inside the hardened bearing race and destroys the shaft. FWIW

 

C

CO Powder

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Dec 24, 2014

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• Mar 4, 2015

• #4

Same failure on my buddy's '13. Started making a horrible noise. If I had to guess, his was probably still torqued to 25 lb/ft being on the original QD belt.

I am paranoid about mine on the 14 now. Still sounds good, no discernible play yet. With no replacements I am not even taking it apart to look, I have a lot of riding planned this weekend.

 

R

rowe

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Apr 16, 2012

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canada

• Mar 4, 2015

• #5

Had the same thing happen to my 13 pro rmk cause of the recall about the QD bolts coming lose. Got new bolts,jackshaft and bearings under warranty

 

C

chriswelters

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Ishpeming MI

• Mar 5, 2015

• #6

CO Powder said:

Same failure on my buddy's '13. Started making a horrible noise. If I had to guess, his was probably still torqued to 25 lb/ft being on the original QD belt.

I am paranoid about mine on the 14 now. Still sounds good, no discernible play yet. With no replacements I am not even taking it apart to look, I have a lot of riding planned this weekend.

Click to expand...

What kind of noise are you talking about? Could you try and describe it?

 

D

dexter

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• Mar 5, 2015

• #7

my 2015 did the same thing on the pto side of the driveshaft. bearing also seemed fine. third driveshaft in mine now. I have noticed more problems in our area with 15s than 13s, pretty sad

 

R

realbass

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Feb 3, 2009

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Russia, Krasnoyarsk

• Mar 5, 2015

• #8

We have a lot of same troubles with stock jackshafts here.
We are producing own jackshaft here in RU some stronger than stock.

 

G

geo

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Dec 1, 2007

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Kamloops B.C.

• Mar 6, 2015

• #9

I think Poo could fix this with a different disc design. Don't think a different jackshaft would make a difference.

The disc starts to wear on the ends (because of small surface area) when bolt torque is lost (look real close). Braking forces applied is part of this. Worst side is the bearing side because of the small radius on the ID of the inner bearing race.
If it never comes loose it will never spin in the bearing.
A floating disc on a separate hub would be ideal IMO.

I fixed mine in 13 and it has never come loose since. Use a thicker washer and 10.9 bolt there too.
I machined 30 thou off each end of the disc and replaced that dimention with hard steel washers (secondary stuff). 4 times the surface area and true square ends.