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Timing belts


Metro Mighty Mouse
03-13-2010, 11:48 AM
Hi guys,

Any ideas or opinions why this metro, (2 different motors), would break the timing belt around every other year? the only consistent factors are Goodyear Gatorback belts and me, and it can't be me!!!! :icesangel: Any ideas are appreciated and will be met with scepticism, (and if I really don't like the answer I'll rage at you and make up bogus facts to prove you wrong).:sarcasm1:

Really just looking for ideas to extend the belt life if possible.

A few facts, 3 cylinder, high flow cat, cherry bomb style muffler, manual, cone style air filter conversion, Spec stage II (if I remember correctly) clutch, currently has a 30 mile commute each way 5 days a week and has been running up to Seattle (2 hours) once or twice a month, used to have a 50 mile commute each way, most driving is at 75 mph on the fwy.

Thanks!!

idmetro
03-13-2010, 12:09 PM
Since we know it's not you, have you double checked the washer with the bevel that acts a keeper for the belt (bevel needs to be facing out).... Perhaps the gear edges on the crank or camshaft gears were improperly machined and are either too sharp or their spacing is slightly off. Perhaps a trip to a U-pull it yard is in order to be able to examine several specimins and see if you can find any difference between theirs and yours.

Best of luck!

Crvett69
03-13-2010, 12:49 PM
couple suggestions, there are 3 different belts for the engines, a square tooth belt for the early ones, a round tooth then a wider round tooth for the newer engines, are you using the right belt for the year engine you have, are both top and bottom gear matched, not a round tooth lower and square tooth upper etc? did you replace the idler bearing? are you tensioning it corectly?

Metro Mighty Mouse
03-13-2010, 02:41 PM
Good stuff. I don't think I installed the washer incorrectly, but I will double check. There does not appear to be wear on the belt when it breaks. It also is not oil contaminated. On belt types, I had to swap my gears from the original motor to the JDM, so that is another thing that did not change. I have been tensioning the belt according to the factory manual. would anyone suggest adding or removing tension to the belt? I have been using the correct belt and the gears do match. Did not replace the idler bearing, but I have checked it each time and it spins freely, no noise or rough spots.

Crvett69
03-13-2010, 03:02 PM
you just let the spring tension it, don't add any extra, i would replace the idler bearing, if washer is correct that only leaves something wrong with camshaft in the head causing extra stress on the belt. might also try a different brand belt next time just for the heck of it

Metro Mighty Mouse
03-13-2010, 06:48 PM
That would be the procedure I've always followed. Schucks/Orielly sold me a Gates timing belt. Disturbingly, it is significantly shorter across than the original and replacement belts. Not much choice so it's going in and we'll see.

Crvett69
03-13-2010, 08:44 PM
you might need to order a belt for a 97 metro 3 cyl, they are wider

Metro Mighty Mouse
03-13-2010, 10:16 PM
faulty memory, same size as what was on the car and fits the pulleys correctly. It was the least traumatic installation of all the ones I've done. The Mouse has been test fired and just needs to be buttoned up. Hopefully I won't need to restart this thread in 2 years. The "funny" thing about this is, it broke in the same spot as last time, I just stopped on the opposite side of the freeway. I could look across to where I waited for a tow. The spot is also 1 mile past the mileage limit of my roadside assistance policy and both times the tow company just waived the extra mile.

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