Cat SX3 rear belt installation issue

[mlee]

Hi All,

I am having problems of installing the rear belt.. After installed the rear belt, I can hear a "knocking" sound come out from the pulley located in the mid section. I have tried reassembled 3 times and still having the same issue. The "knocking" sound disappeared when I take off the rear belt. Anyone of you have this issue or this is normal? Please help.

Thanks,
Mark

[james54321]

am also having a similar problem..

[john333]

are the eccentric bearing holders lined up right? if not the diff will run offset and the belt will bang against the side plates

[martin so16]

make sure you havent put the wrong screws in the wishbones if to long they will hit the diff and lock it up

[moth898]

there is nothing hitting anything, its a tiny slack between the the pulley and layshaft, nothing to worry about

[mlee]

Originally Posted by moth898

there is nothing hitting anything, its a tiny slack between the the pulley and layshaft, nothing to worry about

Everything checked and nothing catching anything...
Thank you for your comforting comment. however, how smooth should the drivetrain be running? It seems that the first Gen Cat SX does not have such issue.

[wes]

Had this problem also and spent ages trying to cure it. Found on mine the noise came from the idler gears being loose on the shafts (makes a slight click during slow rotation) just add a thin washer before installing the nut to take out the slack, check you still have some end float. You may find the mesh of the gears feels tight after this just grease them up and they bed in nicely after a few runs

[mdb_75]

I've seem some Sx and sx2's built with the small gear that the long belt goes around next to the spur gear fitted on the wrong way around. Flipping the gear over stopped the clicking.

[moth898]

Originally Posted by mlee

Everything checked and nothing catching anything...
Thank you for your comforting comment. however, how smooth should the drivetrain be running? It seems that the first Gen Cat SX does not have such issue.

try this, slowly pull the belt and look at the pulley rotate. note that it will click 4 times in a 360 rotation. That is the metal on metal contact between the square shaft and square pulley hole. There has to be a little slack between the two to allow the parts to fit together. Even at the tightest tolerences it can make a little sound. I think the click is caused because of the increased preasure of the new diff belt.

If it really bothers you put a small dab of blue threadlock on the layshaft before installing the pulley it should stop the noise. just be prepared for trouble removing it after.

[tyreman]

I had this on my sx2, the cause for this was the eccentric housings weren't lined up the same.

[mlee]

Originally Posted by moth898

try this, slowly pull the belt and look at the pulley rotate. note that it will click 4 times in a 360 rotation. That is the metal on metal contact between the square shaft and square pulley hole. There has to be a little slack between the two to allow the parts to fit together. Even at the tightest tolerences it can make a little sound. I think the click is caused because of the increased preasure of the new diff belt.

If it really bothers you put a small dab of blue threadlock on the layshaft before installing the pulley it should stop the noise. just be prepared for trouble removing it after.

Thank you Sir. This is actually what I found "4 click per rotation of the pulley". I also find that the noise is more noticeable when pulling the belt towards the rear....
I am not prepared to fight against threadlock in the near future so I will leave it as it is. Thanks again.

[mlee]

Originally Posted by wes

Had this problem also and spent ages trying to cure it. Found on mine the noise came from the idler gears being loose on the shafts (makes a slight click during slow rotation) just add a thin washer before installing the nut to take out the slack, check you still have some end float. You may find the mesh of the gears feels tight after this just grease them up and they bed in nicely after a few runs

Thank you! The issue removed after adding a 0.2mm washer before the lock nut!