I have wondered if the shorter alternator belt would be long enough to use for the power steering belt. I use the Gates 7395 XL for the alternator and the Gates 7400 XL for the power steering pump. The difference is 1/2 inch OC (outside circumference?).

I'm too lazy to go out in the cold garage (Minnesota) and actually try it. It is much easier to post here.

It would be nice to keep only one size on hand for our "fleet" of 940s.

Thanks
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Mine:5-940s running, 2-740, 1-940 parts, dtrs:4-940s

Dear jd620,

Hope you're well. The two belts are 1000 mm (39.4") and 1013 mm (39.9") in circumference. As you noted, the difference (13mm) is 1/2".

If I couldn't get an alternator belt, I'd use a power-steering/water pump belt for the alternator. The reasons: (a) the power steering pump's adjustment range might be limited by its hoses; (b) the power steering pump is harder to access because it is mounted below the water pump; (c) the alternator - mounted atop the engine and connected with relatively flexible cables - is likely to be easier to adjust.

As under-car access is required to remove the air-con compressor drive belt - necessary to access the other two drive belts - this research will have to await milder weather.

Hope this helps.

Yours faithfully,

Spook

Hi Spook,

I'd like to use the shorter belt for the P.S. but will wait for warmer weather to find out for sure. I will post the results here.

I wish the alternator belt was quite a bit shorter. There is a lot of backlash when the engine is revved if the belt is not very tight and I would think the tight belt would be hard on the Denso alternator bearings, although the bearings hold up amazingly well.
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Mine:5-940s running, 2-740, 1-940 parts, dtrs:4-940s

Dear jd620,

Hope you're well. If there's "a lot of backlash when the engine is revved", that might suggest the rubber bushings are "on the way out", and so allowing the alternator to move, when engine revs jump. I'd inspect the alternator bushings to see if the holes, instead of being round, are elliptical. If so, I'd replace the bushings and see if that doesn't cure "backlash".

My "rule of thumb" in adjusting belts is that they should be snug to the point that a single finger's pressure - applied at the mid-point between the pulleys - should depress the belt by 3/16". At the risk of laboring the obvious, this test is not to be done on a moving belt.

Hope this helps.

Yours faithfully,

Spook