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Murray has a kit in the works (no word on exactly when it'll be on the market) automatic cam chain tensioner rebuild kits, consisting of a new thrust button, springs and pin. This install is based on the pre-production variant which lacks the new springs and pin, but should otherwise be identical. Here's your automatic tensioner:
It's one bolt to remove it - see here. Once removed:
Using a vise or vise grips, grab the pin that's in the middle of the tensioner body - the one that doesn't go the whole way through the tensioner - and remove it. Once you release it the spring will push the plunger out, so don't position it so that it will fall out. Ours didn't have enough spring tension to propel the plunger out of the slot fully.
The plunger in question:
Spring removed:
Now we can clearly see another pin running through the plunger, holding the thrust button in place:
You won't be able to grab it with vise grips like the last one, you will have to drive it out. There's another spring inside here but same with the one above, it didn't shoot terribly far:
Thrust button, internal spring, pin. This little pin is responsible for many tensioner failures and consequent engine damage; it moves back and forth against the hardened sides of the hole in the plunger, eventually failing and releasing the thrust button. The thrust button can then bounce back and forth and if it gets stuck between the tensioner blade and the plunger can snap the tail off the tensioner. The little spring around the thrust button is also then free to migrate around the engine as it pleases, which doesn't really end well for either the spring or the internals. The rebuild kit we are using today does not re-use this pin, nor the smaller spring that sits around the thrust button.
Closeup of spring:
New thrust button next to old thrust button:
The additional thickness takes up a lot of the extra slack and prolongs the usable chain life.
Mix up some Marine Tex or JB Weld - we had white Marine Tex on hand, though you could use white or grey - and push some down into the plunger:
Add some to the end of the new thrust button:
Push the thrust button into the plunger end. It's a tight fit and the recommended way of getting it to seat properly is using an arbor press or a vise to squeeze it in. Any excess Marine Tex will come out the two holes - clean it up.
Once the Marine Tex/JB Weld has set (or you're confident it's not going to run out and gum up the spring etc.) put the spring over the plunger:
Using something long and hard push the ball back up it's ramp and hold it there against it's own spring:
While pushing the ball up, slide the plunger and spring into the assembly and hold it in. Once it's in the whole way you can release the ball. You should be able to slip a small drill bit or something similar through the hole at the end of the plunger and the matching hole on the tensioner body, which will hold the plunger in for you. Photo of that coming.
Grab the first little pin you took out and put it back in it's hole:
A quick tap with a hammer should seat it:
Slide the tensioner back into place in the engine and once it is seated remove the drillbit (drillbit not in place in this photo):
...and all done!
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