Inliners International Forums General Discussion Engines Alternator belt tension

Anyone else having the problem of the alternator belt just loosing tension all the time? I keep finding myself killing my battery, then finding the alternator is not turning enough because the belt is loose. The location of the alternator under the PS pump makes it tough to adjust on these Chevy inlines. I get a pry bar to put the tension on the alternator, against the block and bracket, with one hand while tightening the adjustment bolt down to lock the tension with the other hand. But it always seems to work itself loose over time? I keep replacing batteries because of this.

Are you tightening both bolts not just at the slide.

I have.....maybe I'm not tightening the right two?

While it shouldn't be necessary maybe instead of a slotted adjustment strap you could use a turnbuckle. I do that on my race car.

That's a pretty good idea. I'm not sure if the slider bracket is part of the PS bracket above it or is removable?

I have the 1/2" both on the slider bracket above. Then there is the through bolt on the bracket on the bottom of the alternator, which has a bolt head on the front and a nut on the back. Correct? That bottom one is a pain with two wrenches. I wonder if I'm maybe sliding the alternator backwards while tightening the bottom?

Here's my procedure: I loosen the bottom bolt and nut so they pivot, then I loosen the slider bracket bolt, I take a pry bar between the PS pump and alternator and pull the alternator as taught as I can, then I tighten the slider bolt, then I tighten the lower bracket bolt and nut.

Is there a better way to do this, or should I just always have a second set of hands around when I do this to keep the tension on during the whole procedure?

There is always a belt tension jack:

MSC Direct

That would replace a set of hands.

I had the same problem on an old big block that I ran in my tow truck.. I replaced the bolt through the slide bracket with one that threaded all the way through the ear on the alternator. After that, when I adjusted the belt, which became a seldom needed task, I tightened the slider bolt. tightened the lower bolt and then tightened a nut on the back end of the slider bolt. I discovered that the bolt in the ear of the alternator was loosening during operation and the "double nut" kept it from doing so.

I also added a hardened washer under the head of the adjuster bolt and one under the double nut. The factory washer was too soft and deformed over time and repeated adjustment.

Thanks. Sounds like the same problem I'm having. I haven't had the bolts off of it since I replaced the alternator. My alternator is clocked for a small block and I need to take it off and clock the rear housing so that the wires are not to the inside toward the block and facing outward for easier access. I could check out bolts and washers, and replace them then.