[Wyatt McCandless]

I have a 2008 honda rancher 420 2x4 and I keep hearing a rattling noise from the bottom end I'm pretty sure it's the cam chain what all do i need to do to replace it?

 

[fishfiles]

...do you really think it is the timing chain ? if the chain is worn bad it will make the engine run bad as it will be out of time ----- it could be the connecting rod you are hearing , I think I would line up my timing marks and see if the chain is stretched out before going any deeper into it

 

[Carolynskii]

Fishflies is correct it could be several things but to access the chain you need a 10mm socket to pull the front cover. If it’s 4x4 then you need to disengage the front drive drive shaft by loosening the front diff and pushing it forward.
Once you have access and confirm there’s a problem you’ll need a 1 1/16 or 27mm socket to remove the pto clutch and a clutch puller.
Once the clutch is off you can replace the chain tensioner and guide if needed. If you need to replace the chain then proceed to remove the topend (plenty of videos online) so the cam guides can be taken out in order to get the cam out with a 12mm socket and swap the chain.
Put the crank at TDC and line up the mark for timing and put her back together. After the head is on confirm you are in the compression stroke and adjust your valves to compensate for the new chain.

 

[Wyatt McCandless]

That's the thing it's still running perfect I know the valves chatter but this noise sounds different almost as if a bolt is rattling in my engine

 

[SamUK]

Download the service manual and check the timing, you’ll soon tell if the chain needs replacing as the marks won’t align correctly.

The noise could also be a bad tensioner or even clutches, centrifugal clutches make a right clatter when there worn.