Top gear does it need replacement

[vmxrdr]

With lack of snow we have been doing maintenance rather than riding sadly, I seriously can’t pinpoint what causes such inconsistent wear in these bushings. Just replaced one in a buddies 2017 that was completely sacked out with 8,000 kms running yamalube chaincase which I understood. My 17 stock bushing with yamalube chaincase lube sacked right out by 2,000 kms, not sure how tight guy that owned it for first 1,300 kms had the chain though. Just took same sled that my son owns now apart running a bit extra pennzoil 75w140 synthetic gear oil and 1.5 turns out on tensioner per recommendations on here for 10,000 more kms getting the crap ridden out of it with a powertrail tune and the updated 18 gear is like new, we are leaving it in.
I really don’t get it.
The drive axle bearing on my old 17 is a different story though. Getting a couple repaired rather than wait for new ones that are back ordered.

 

[74Nitro]

With lack of snow we have been doing maintenance rather than riding sadly, I seriously can’t pinpoint what causes such inconsistent wear in these bushings. Just replaced one in a buddies 2017 that was completely sacked out with 8,000 kms running yamalube chaincase which I understood. My 17 stock bushing with yamalube chaincase lube sacked right out by 2,000 kms, not sure how tight guy that owned it for first 1,300 kms had the chain though. Just took same sled that my son owns now apart running a bit extra pennzoil 75w140 synthetic gear oil and 1.5 turns out on tensioner per recommendations on here for 10,000 more kms getting the crap ridden out of it with a powertrail tune and the updated 18 gear is like new, we are leaving it in.
I really don’t get it.
The drive axle bearing on my old 17 is a different story though. Getting a couple repaired rather than wait for new ones that are back ordered.

So the one with the looser chain and extra oil lasted longer. I would say that is good as that is the consensus it seems.

 

[ryama]

Can someone tell me, If this bushing fails, does it stop you from using the machine, or does it stop the use of the reverse function?

 

[cannondale27]

It will grind the gears and then it wont fully engage in forward. From there its catastrophic if under power it disengages. At what point of wear that occurs I dont think anyone knows but its happened often enough that I dont want to find out myself. I have also seen where bushing fails and just chews up the shaft. No other damage.

 

[ryama]

I had sled apart 600 miles ago. Second guessing myself and trying to decide if I pull it apart and check again.