sparkygooner

Alternator Belt Keeps Snapping

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Hi All

I have a 1990 RX7 Turbo II Convertable and the alternator belt keeps snapping. The belts are fine for the first hour of driving then start to squeel and eventually break into pieces.

Please could someone offer some advice as to the problem? There appears to be no movement in the alternator and it spins turns no problem. Could it be something to do with the tensioner?

Any suggestions would be most welcome as I have another two belts from Mazda waiting to go on..........

Many thanks,

Sparky

TweakGames

iTrader: (3)

you have the alternator spacer on the wrong side.

phoenix7

Using the correct belt and it's not too tight? Make sure you don't overheat since your waterpump won't be fully functional.

glh-fc

his car is a S5 like he posted.no spacer on the alternator.

to the OP,did you replace the water pump before?cause on S4's there are 2 spacers that go on the water pump housing but on S5's those washers throw off the pulley just a hair off and shear belts since the S5 housings it's already casted onto it.

mustang_kicker

I actually had that same problem on my 89 gtu a few months ago. What i did was pull the water pump pulley off and i placed a washer on each stud behind the pulley. It didnt move it out much but i guess just enough because i havnt had a belt snap since. Also tighten the belt only snugly, dont use any tools for leverage just pull up on the alt. as much as u can by hand and tighten the bolts. Good luck with it.

TweakGames

iTrader: (3)

Opps! Didn't catch that! Good call thanks.

Craiger

iTrader: (1)

Look and see if all the pulleys appear to be in line and make sure there is not too much play in the water pump bering.

Since you have 2 new belts waiting to go on I assume that you have a double alternator belt pulley but if this is not the case and your not running an air pump then you should make sure you have some kind of second belt running the waterpump.

Make sure the surface where the belt rides is smooth and free from anything that might cause any extra wear on the belt.

sparkygooner

Thanks for all your advice. I'll try this weekend.

Thanks Craiger - The belt in question runs from the alternator to the water pump - this is the one that keeps snapping. I got the other one as a spare. All belts are main dealer Mazda parts so should be correct.

I have not replaced the Water Pump previously. It just seems strange that inialtially it runs fine when the belt is first replaced but once it warms up it squeels and snaps.

My Car RX7 is the 2nd Gen convertable (1990) only sold in Europe.

Please feel free to give me further advice.


Thanks Again

Sparky

Black90RX7

I actually have the same problem. I replaced mine about 3 times. It sucks I dont know what can cause it to happen..

Craiger

iTrader: (1)

The question was how many belts are running the waterpump. A lot of times people remove the emmissions control stuff and the air pump from these cars. On the waterpump pulley you will see two sleves for 2 belts to ride on. If you have your air pump removed then chances are there would only be one belt driving the waterpump which can cause the belt to slip and eventually break. I really doubt this would be the cause of your belt breaking since your is breaking almost as soon as you put it on, but none the less you should look into this.

If the pulleys are lined up properly and free from anything that could cut the belt, i'd bet you have a bad waterpump bering.

MmSadda

iTrader: (2)

Make sure it's not too tight. Use belt dressing. Make sure you're using the right belt.

kerpal

I suggest that you change the tensioner, timing belt and the pulley as well.

Craiger

iTrader: (1)

I assume this is a joke right??

If not, FYI, the tensioner is the alternator, why replace the pulleys before they are inspected, and please let me know where the timing belt on a rotary is because I have been looking for it for over 2 years!!!

P.S. There is no timing belt!!

Houpty GT

I have the same problem. What I think it breaks down to are several things. The size and design of the alternator pulley and the material of the pulley rusting and scoring the side of the belts.

I sanded the pulley where the belt rides and have gotten my belt life up to several months. I intended to install the aftermarket pulley for the air pump removal mod but still run my air pump. Here is the link:
http://www.rotaryinnovation.com/new_products1.htm

And my old thread:
https://www.rx7club.com/showthread.p...=1#post6714995

Nitrometano

since I installed a double belt pulley in my S5 alternator, no more problems with belt slipping. I think you can try that. I brought mine from ojperformance.com. Just make a call and they will get the correct pulley for your engine.

Akagi RedSuns

I had the same problem with mine. At first it was the belts running at an angle because of the alternator spacer. I switched it from the front to the back. Make sure that the belts line up straight, that there not to tight, and there the right size. I would recommend some goodyear gatorback belts because there really heavy duty and don't slip off.

glh-fc

like stated previously,he has a S5 meaning there is no spacer for the alternator.it is casted onto the bracket on the waterpump housing.

Akagi RedSuns

Sorry forgot about that. Never mind then.