Adjusting belt tension on an 80 - good tool

[sbman]

At the 1000 mile mark on my rebuilt motor, I did a minor service that included adjusting the drive belts.

The FSM gives specs to tighten the belts in pounds and indicates some expensive belt tension measurement device to get them to specification. I didn't have that tool so I ordered a Gates 91107 tension gauge. This is an inexpensive tool (about $12) to set your belts to spec.

To use the tool, you clip your finger into the stretchy strap and then put it on the belt. You press against the belt with your finger on the tool until it clicks like a torque wrench, as soon as it clicks you stop putting pressure. The plastic arm deflects out of the front of it and gives you a reading. I found it to be very repeatable. There's enough room to get it on the belts easily and check the tension. I removed the lower plate to access the A/C tensioner assembly and that also made the alternator tensioner easier to access.

I know people say just snug em up. I tried that first. I 'snugged them up' the way I always have and then checked them to see if I was anywhere close. On the A/C belt I was way UNDER the spec, which can lead to premature belt failure. On the alternator/fan belt, I was way OVER spec, which can lead to premature alternator and water pump failure. It's easy to use, accurate and gets things set for maximum life, so I'm happy with the tool.

 

[NLXTACY]

Not the one I have but I too was surprised how way off the belt tension was.

 

[Landseer]

I bought one of these a year ago, its really nice to get a measure of the actual tension. Definitely worth the $12.

 

[blkprj80]

Thanks!
I just ordered one for $11.70 with Prime shipping on Amazon.

 

[Dissent]

Great idea, bought the same one and used the heck out of it.

 

[Alleycats]

So on the topic of belt tension it seems some argue that to tight of belts leads to premature bearing failure. I have one of the gizmos you refer to, but it wants my belts way tighter than seems necessary.

 

[Dissent]

Toyota spec isn't too tight. Remember that it takes 35 HP to in an A/C compressor and 5-15 HP to run an alternator. That means quality belt tension and solid pulley contact to turn those devices. Beyond the factory spec, you could definitely put undue stress on the bearings. Use the gauge and stay in spec.

 

[thetoyotaman]

Thanks for posting this. Great idea!

 

[sbman]

After adjusting properly I noticed that it idles noticeably quieter. It seems like new, somewhat loose belts don't squeal, they swoosh.

 

[jafo9]

thanks for the part number. amazon prime on the way.

 

[Cruiser804]

Mine were at the lower end of the spec. I tightened them to near the higher end an o have to say it made a significant difference in the noise the belts made. Thanks!

 

[Qball]

Bump and need to order me one from Amazon

 

[NLXTACY]

Bump and need to order me one from Amazon

Just borrow mine

 

[Qball]

Will have do that next weekend

 

[Mlachica]

Thanks for the heads up on the tool. My thumb sst said my belts were too tight, got this tool to find out I was under spec.

 

[OffGridOverland]

I use a hz tool. Or you can down load a sound app to your smartphone. The measure the flick at the belt.
Make it repeatable 3 times. Then call it a day.

 

[e9999]

I love gadgets and tools so I don't mean but to be overcritical but I don't see how this gizmo could produce a number that you can compare to the pretension figures given in the FSM, which are surely for specific professional devices measuring deflection over a fixed known span. This one does not seem to do the latter from the little I can see. It seems like it measures absolute deflection which would depend on the span between pulleys, not even getting into the issue of what material the belt is made of, which would greatly affect the result too I imagine. I suppose after calibration with a known standard, this could be useful, or if there is a table for that specific device for specific belts for specific spans that would be fine too, but without that I don't see it. Somebody tell me?

 

[Dissent]

Belt tension and deflection has little to do with pulley span. Check the pic of the tool used in the FSM, it measures tension over a few inches just like this tool. It works.

 

[e9999]

I don't have one so I'm guessing here but it seems to me that this tool just sits on top of the belt without grabbing it and you basically deflect the belt a certain amount until it clicks and then "measure" the force needed to do that. Is that not so? If it is, that is not the same principle as the pro deflection tools mentioned in the FSM. And even if it were, if the span used is not the same the numbers would not be comparable, seems to me, cuz I think the span matters a lot for deflection. I'll admit I'm no belt expert, though. But until I know better, seems to me that this gizmo gives you a number all right but I don't see how you can use the FSM numbers with this particular gizmo with any level of quantitative confidence.
I'll readily admit that this is more fun than just pushing on the belt with your finger, though.

 

[Dissent]

I've used mine to confirm after getting my belts replaced, with other stuff, at the dealer. The belt was in spec and I assume they used the FSM specialized tool.

I've seen lots of folks who assume a torque wrench isn't necessary and those who use them religiously, I'm in the latter group. Doesn't matter the brand or style of wrench, just that it confirms the torque to spec.

Just my .02.