New Driveshaft ID Smaller

[rtx moose]

Ok everyone there is an actual bearing fit tolerance that is standard world wide so if the shaft is not in tolerance the bearing will not fit correctly period..this is not a cat engineering problem it is a cat quality problem!!! This is an measurement that needs to be checked by a pressure mic not a caliper..also the tolerance of the inside diameter of the shaft is wide open probably +/- .005 at the least compare to the +/- .0003 or whatever of the bearing tolerance!!!PLANE AND SIMPLE INCOMING INSPECTION FROM ARTIC CATS QUALITY DEPT FAILED!!

 

[Turboflash]

What does "fit correctly" mean to you in this case?
There are many on this site that know how to measure a shaft or bearing diameter.
Are you saying that in every single case where the shaft bearing journal was accurately measured to be less than the ID of the bearing, it's because the shaft was defective? Really?
I personally have never heard of a single case where the shaft journal was larger than ID of bearing over the last 3 years.
The shaft journal has always been smaller than bearing ID so bearing has always been a slip fit - never an interference fit.

 

[cannondale27]

What does "fit correctly" mean to you in this case?
There are many on this site that know how to measure a shaft or bearing diameter.
Are you saying that in every single case where the shaft bearing journal was accurately measured to be less than the ID of the bearing, it's because the shaft was defective? Really?
I personally have never heard of a single case where the shaft journal was larger than ID of bearing over the last 3 years.
The shaft journal has always been smaller than bearing ID so bearing has always been a slip fit - never an interference fit.

I agree but a slip fit is not what the factory is giving us in most cases. I would have to look it up in handbook but .0005 in. less than ID of bearing is what I shot for. The factory was sending many out .002 or even .003in less. That’s just a sloppy fit for lack of a better term.

 

[rtx moose]

If you guys want details on the bearing fit tolerance find a machineries handbook and look it up

 

[rtx moose]

I agree but a slip fit is not what the factory is giving us in most cases. I would have to look it up in handbook but .0005 in. less than ID of bearing is what I shot for. The factory was sending many out .002 or even .003in less. That’s just a sloppy fit for lack of a better term.

Yea thats really bad if they were that far out of tolerance,that is strange in my lifetime I have never seen this problem before..this is a big quality problem for cat for what its worth

 

[Turboflash]

In order for it to be strictly a quality problem, that would mean every shaft is machined out of tolerance (compared to the Cat blueprint). This cannot be the case. IMO, it is a Cat DESIGN defect. The Cat design fit of the shaft to the bearing is NOT designed as an interference fit (interference meaning the the shaft OD is larger than the bearing ID. Bearing would need to be pressed onto shaft and could not be slid or slipped onto shaft).
I want a reliable and robust way for the shaft and bearing to be locked to each other. With Cat's design it will not happen because the shaft is specified smaller than the ID of the bearing. Of course, I have never seen the actual engineering drawing for the shaft (I certainly would like to!). I only say this because I could see some shafts machined wrong, but not ALL of them. Therefore, I have to assume whoever is machining these shafts is meeting Cat print (mostly).
The only way to guarantee the shaft will not spin in the bearing is to lock the two together. Hence the BOP McWedgy thing which when tightened, swells up the shaft enough to take up whatever the difference is. I chose to have my shaft journals made larger to guarantee an interference fit.
You can look up the myriads of posts on this subject and see some actual measurements on new shafts. The journals are smaller than the bearing ID.

 

[Turboflash]

I agree but a slip fit is not what the factory is giving us in most cases. I would have to look it up in handbook but .0005 in. less than ID of bearing is what I shot for. The factory was sending many out .002 or even .003in less. That’s just a sloppy fit for lack of a better term.

I've NEVER heard of anyone who got a new shaft where the bearing journal was larger than the ID of the bearing. Full stop.
Mine now has both sides where the journal is larger than the ID of bearing; bearings were pressed on (.0002-.0003" interference).

 

[cannondale27]

I've NEVER heard of anyone who got a new shaft where the bearing journal was larger than the ID of the bearing. Full stop.
Mine now has both sides where the journal is larger than the ID of bearing; bearings were pressed on (.0002-.0003" interference).

Yes and you never will see that from the Factory because it makes for a assembly and disassembly issue. Also long term it may end up harder on the bearings and shaft because there is no give and side forces could effect life. I don’t know but a proper slip fit worked on mine this year.

 

[rtx moose]

I've NEVER heard of anyone who got a new shaft where the bearing journal was larger than the ID of the bearing. Full stop.
Mine now has both sides where the journal is larger than the ID of bearing; bearings were pressed on (.0002-.0003" interference).

yea it would not be assembled if it was too big but yes these shafts were made in a couple of batches and if there was a tool change and someone forgot to change the offset then this could easily happen!!in the machining world its called SPC inspection so you can keep an eye on tool wear..trust me this stuff happens i have seen thousands of bad ground parts make it to a customer just like these shafts..I am not trying to disagree with you its just i have been a Quality engineer and in the supplier quality position also for 20yrs..if anyone ever has questions for me about quality i will be glad to help

 

[hibshman25]

I got some measurements back from a 2021 drive shaft and it had an ID of 2.255-2.557, so no reason to believe my drive shaft saver will not work on 2021 models.

 

[slimjim2525]

My BOP mcwedgey has been in since last year. A little over 5k miles last year. I now have the sled home and will be tearing into it today and tomorrow. Will see what the drive shaft looks like. It was perfect beginning of last season when the sled had 2k miles on it, now 7,200 miles. Also can't wait to see how the upper gear Mcmaster bushing held up. That has about 4k miles on it. Will report back.