tryin to help a new quad owner with a chain-type noise prob on his scrammy. Here's the copy/paste from the last email... your input is always valued and muchly appreciated,... thanks in advance, guys.

Hey there, probably figured out where the noise is coming from, it's not gonna be the easier thing to fix (no time before the long weekend). The main drive shaft coming form the gear box has the sprocket for the rear chain, then the rear brake rotor, then the sprocket that drives the front chain. The sprocket for the rear chain on the drive shaft, has a bit of side to side play, and it appears the spindles are worn on the sprocket as well as the drive shaft. I believe the noise is caused by the sprocket slipping on the spindles of the drive shaft under high torque conditions. Tom will be pulling the sprocket off to look for wear. The front sprocket on the same drive shaft has a bit of wear on the spindles as well, but I don't believe it is slipping, and it is not subjected to the same force as the rear drive. Judging by the noise and when it is created (high torque situations only), it make sense that this is the problem. I think that the main rear sprocket should not have any side to side play(wobbley), as that is an indication of wear (sprocket...drive shaft...or a bit of both). Might be able to tack weld the sprocket on drive shaft for a temporary fix (is that a good idea ???????), but when it needs to be replaced, some cutting will be involved. If it's not that, it almost has to be a gear box noise, which I'm hoping is not the case. Probably with the new tires hooking up really good, the drive shaft\rear sprocket is subjected to more force.

I'll probably just drive it the way it is, as it works very well unless high torque is exerted. I'm going to have to replace the pieces anyway (drive shaft from gear box, rear sprocket, front sprocket). Hopefully it will make it thru the weekend.

 

I would say the chain in the tranny is loose making the pop sound.And if it is and you dont fix it it will break and you will need a new transmision.

 

I cannot fully understand what he is talking about, but,, The rear sprocket should have zero side play in it. It bolts onto the sprocket hub via 3 bolts, then a spacer, then the sprocket protector. If any of those bolts are loose, it could cause a wobble. Looks like this. Now if it is the front sprocket at the tranny, it will have some side play in it which is normal. It sounds to me the popping he describes could be a chain or sprocket problem, as in worn out. If the chain is o-ring and the o-rings are gone, there could be a part of the chain that is seized and causing the popping when it rides over the sprocket. If one of the sprocket teeth are messed up, it could do the same thing. The chain has to be adjusted properly also which could cause problems. Is the tranny fluid full and in good condition? Alot of noises can come from that also. I also agree with what Ftwflh said. IF, the sprockets are found to be the problem and if just one tooth goes, they will all go right then and cause major damage to the tranny housing, I have seen it happen. Good luck.

 

Thanx to both of you for the responses.... they are in the process of tearing down to find out wtf is wrong,... chain tension and adjustment seems to be good, and my buds really appreciate your input. I'll let you know how it turns out. If any others have more info to throw at me please do, this is all new to me.
Thanx again