Ive noticed a pattern with several Nissans ive had over the years, and with the exception of the Hardbody's (all versions) from 1987-1995, with the VG30 V6 Engines using V belts and the 4 Cyl Z24's from 1983 through 1989 are fine with aftermarket belts.
However..the 4 Cyl KA24 From 1990-1997 HATE anything but Factory Nissan V Belts.
Particularly the Alternator Belt, and it worsens when you first start running under anykind of load (lights on, A/C powered, Powerful Stereo..etc etc) and will squeel like a stuck pig once its been run a bit, but will quiet completely or will still squeel somewhat as it warms up.
The V6s seem ok with all belts, but Im not aware of any issues after the 1998 Frontier came about and the new VG33 V6.
I believe Nissan went to a Serpentine belt (flat with grooves), and I havent heard to many people complain about them.
Serpentine belts DO loosen over time even though they last alot longer than a V belt. They almost need to be guitar string tight, but once you set them, they tend to stay put. But Different Manufactures use different grades of rubber and should be checked at least once in 1000 miles after installation as a matter of course.
I believe there should be about 3/8 Inch deflection on a V belt, and about a 1/4 inch on a Serpentine. Be careful how you tighten the belt, and dont forget to loosen the lock bolt before you start cranking the adjusting bolt on each accessory!
The Jack screw system is used on All Hardbody engines except the Alternator belt on the Z24 Engines from 1986 1/2-1989. The Jack Screw system is very handy.
Again, watch the tension you set or it will slip if set too loose, and will ruin bearings (waterpump, alternator powersteering, and AC) if its set too tight. The above method I use is pretty accurate, allthough a shop manual (like Haynes) will tell you the exact "tension" and correct measurements needed, so you may want to consult one.
The 3/8 Measurement is very close, but I think its even less if you arent using a Nissan V Belt (OE) on the KA24.
Keep in mind that no matter what belt you use, the V belts always stretch in the first 200 miles, and will again upto about 1000 miles before being totally seated.
Be SURE if you have a V belt that you go back in and retighten it before it gets loose enough to squeel.
Trust me.. It WILL. And If you dont, once it loosens it will cause heat damage to the sides of the belt where it rides in the groves of the pulleys and the belt wont grip as well as it could otherwise. (this is called "Glazing")
In most vehicles you dont need to worry about this kind of scenario, but the Nissans with the KA24 use an odd size pulley on the alternator, and it seems to react with the abrupt turn down from the waterpump pulley.
Probably something to do with the difference in RPM and the engine torque on the pulley's shifting against a pretty short and narrow belt.
So, again.. Use Factory Nissan Belts in ALL KA24 4 Cyl Engines.
I hope this helps.
