Anyone ever seen a "shoulder bolt" on the timing tensioner pulley?

[blueapple]

I had a discussion with a co-worker, and he insisted that there exists such an arrangement. Where the tensioner pulley (Spring tensioned) is never really tightened down, and allowed for self adjustment. I have never seen it. and it sounds like a source for noise... All Toyota I've worked on had a non-self adjustable tensioner with a straight bolt

Has anyone ever seen something like that on a 5SFE?


Picture of a shoulder bolt:

http://www.suburbanbolt.com/images/-0030.jpg

[new echo owner]

Did he say how it would maintain the proper tension of the timing belt? The spring that the engine has isn't strong enough to do that!

N.E.O.

[blueapple]

I have no clue how the detail is going to work out. I think the spring could be strong enough on increasing RPM, but I don't know if sudden drop in RPM could make it skip or not. I don't believe Toyota ever used that design, but I'm just curious, since there are so many variations of 5SFE (most of what I know is just electrical stuff)

[new echo owner]

The factory spring isn't strong enough, the first time you hit the accelerator the timing belt will skip if the bolt for the tensioner is not tighten down. Just try turning the can or crank with the tensioner loose and it will happen.

N.E.O.

[toyomoho]

Never heard of this free moving pulley arrangement on this engine.

Other makes of engines also lock down the pulley.

There are setups that allow movement of the tensioner pulley but doubt under this application.

[ghettosled]

going by the concept, it would make sense to not have the tensioner bolt snugged down to allow stretch on the belt. but on toyotas, the way the belt is made it should never stretch so the tensioner shouldnt need to be tightened to pull in slack.

[blueapple]

I'm not sure about never stretching. I know the 20v 4age had hydraulic tensioner driven by engine oil pressure.