Noisy Belt & 1990

My dad just gave me his old 1990 M, which I LOVE, but when the A/C runs, I get the whine on & off.... He's also never had ANY belts replaced (It has

82K on it), and has never heard anything about his crankshaft. So... should I just not worry about the crankshaft if it's been okay this long, or is the crankshaft something to worry about only if you mess with any of the belts?
Reply to
Lisa
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I ended up changing the timing belt in my '90 Miata at around 80K the first time. This is a good time to replace the other drive belts as well, as they have to come off anyway to do the timing belt. I also changed it around 150K because the water pump failed and I figured it would be the right thing to do. I was going to let it go to 160K, but it had other ideas. To do the water pump, the drive belts and the timing belt have to come off.

From my experience, I would suggest doing the water pump when you do the belt. The pump may go a lot longer, or it may not. I replaced the water pump in our '97 Protégé this weekend. It was leaking and the belt was way overdue at 102K. I believe the pump is the same as the one in the Miata...it sure looked the same. So that's two of them that failed on me at 102K and 150K. By the way: the Protégé timing belt was showing real wear; the Miata belts didn't look all that bad. That may be the difference between 80K and 100K, but it convinced me that 80K is a realistic limit.

If the front oil seal is not leaking, you might change the belt and be done with it. If the crankshaft drive pulley for the timing belt has to come off, I strongly suggest that you use either Loctite or JB Weld when you put it back on.

Besides the problem with the keyway, which has been discussed in various on line forums, I am convinced that there is a design error in the crankshaft drive pulley itself which can cause it to rub against the front of the engine block. For this reason, I strongly suggest that the crankshaft pulley be replaced with a new one from Mazda. There is a slight change in the new part that improves it from the old and it does not rub. I believe that this, in conjunction with the keyway problem, will result in failure if straightforward (by the book) removal and replacement is done.

Best of luck.....your Dad may have started you on a lifelong love affair with lightweight roadsters. You could not have a better initiation than with a Miata.

Ken

Reply to
KWS

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