I've read lots of different posts about bushings chewing out on the R53 belt tensioner. I'm convinced that the only reason the bushings chew out is if they can't swivel i.e. the bolts are too tight. My solution is to use an M8 x 1.2 part-thread bolt that has a grip length of 19mm (the width of the sleeve inside the bushing plus a 1.6mm washer). This allows the bolt to snug down as tight as you like whilst the non-threaded part allows the strut to pivot freely as the damper moves in and out.

There are also reports of the tensioner failing completely, causing much damage, when the stab-o-shock fails. My solution to this was to add another one for redundancy. The bolt length has been adjusted accordingly to allow for the extra strut..





There should be little to no lateral load on the struts, so the nylon washer should hold up ok. I'm running a combo of Powerflex bushings on the strut that is against the tensioner body, and standard bushings on the bolt-head side. The reason for this is two-fold... The strut at the bottom has to also manage some load from the second strut, so has the stronger bushings, and also I can keep an eye on the wear of each type of bushing as time goes on.




I haven't fitted to it to the R53 yet, but I'll report back if any problems.

Hopefully this helps, or provides food for thought, for anyone else experiencing tensioner issues.

 

That’s very clever.

 

Love the look and the thought behind it but it's not the tensioner shock that causes the problem. It's the degradation of the plastic bushings at either end that dry, crack then fall out causing the shock to not only rattle loudly against the bolts at either end mimicking the "death rattle" but also to lose belt tension It seems to me that you've doubled the load on the serpentine belt and other drive components so I'll be interested in knowing, long term, if this is a help or a hindrance.

 

Tension comes from the spring, not the dampener.

 

Old military term: "Dual channel for reliability". Very much akin to race-prepped cars using dual ignition systems. If one fails, flip over to the other.

 

Agreed. But, two dampeners will not allow the spring to operate normally as now they create twice the rebound force. I stand by my original comment.

 

I love this idea!

Very clever indeed and I'm quite surprised that no one has done it before that I'm aware of.

I am intensely interested in hearing future reports.

I have the feeling that everything would be okay as in my opinion the tensioner is under-damped from the factory anyway, but I'm no engineer so dunno how or if a doubled pressure rate (would that happen?) may affect load forces (maybe on pulleys?) but isn't the spring mainly responsible for maintaining 'positive force' and the damper is for 'negative force' kickback rebound or whatever? If so, then a doubled-damper would add no additional load, am I right or am I wrong?

 

Correct, it’s a dampener, not a pressurized strut. Ergo no additional load. Just double the dampening.