timing chain tensioner breaking

[muddzilla94]

ive broke about 6 timing chain tensioner's in the past 6 months on my 400, does anybody know why this has happened to me and has anybody else had this problem too? im getting tired of buying them, i just ordered one again today along with a new cam and cam chain.

[F-16Guy]

Sounds like user error. The tensioner needs to be fully retracted before installation, bolted to the cylinder, and then released to tension the chain. To retract the plunger, remove the Phillips head cover screw to access the flat-blade retractor screw. When I do mine, I put it on a bench or solid surface and use my body weight to help depress the plunger while I turn the retractor screw clockwise. Once you have it fully retracted, it should stay that way (you may have to try a couple times if it won't stay). At that point, you can install it onto the cylinder. Once bolted in place (don't forget the gasket), turn the retractor screw CCW to release the plunger against the chain. The plunger is spring loaded and has a one-way ratcheting design that only lets it move outward so that the chain stays tight and the tensioner takes up any slack due to chain stretch.

[bigbad400]

you done something wrong. when you get a new one it should come with a plastic thing in the spot were you rewind it. dont move it until its installed on the motor. it in there to keep it retracted for installation. once installed and bolted in pull the plastic thing and it will snap into place, if you dont hear it snap it may be stuck open, youll need to put a small flatblade in there and wiggle it until it releases. dont forget to adjust your valves after your done. if you got a aftermarket cam youll need to make sure you remove the spring and plunger on the decompression in the valve cover. make sure to use assembly lube on the new cam and such too or you will regret it. you can purchase it at any auto store for like 4 bucks. personally i use lucas oil assembly lube, its 4.23 here. thick as honey but slippery as can be. safe with any viscosity oil. good luck and dry starts can cause serious problems, at least put motor oil on everything befor you start it up. good luck.

[muddzilla94]

ive been doing it the way you said too F-16Guy but it still does it. do you think a stretched chain could be making it break?

[F-16Guy]

When you say it "breaks", what is broken? Does a part physically break off, or does the plunger lose all of it's tension and just move freely? What exactly happens?

[katch26]

are you "unscrewing" the tensioner or just pulling the driver out? if you dont unscrew it and pull the diver out it will pop out at a load and could mess up the ratcheting

[muddzilla94]

sorry i didnt put that better, but the tensior looses all of its tension and just slides in and out like the spring is broke.

[badboystrue]

Is there wear on the tensioner tip? If so theres no guide left.