timing belt reuse

[wengr]

hello, I've long been aware that every source warns against reusing a timing belt that has been removed. even for very low use nearly new belts. I've often wondered if this is a better safe than sorry strategy - or if there is some actual physical reason for it. Let's say you install a new belt, you tension it, you drive around the block then you realized that you screwed something up requiring the belt to come off. Would you actually get a new belt? I know I would reinstall the same belt. What about a week and 100 miles? a month and 1000 miles? I realize that once it is approaching half it's life or so, while it's off you might as well renew it and save yourself a belt job, But discarding new belts seems silly to me. If the belt actually can't take being removed carefully and reinstalled once or twice then maybe someone needs to engineer a better belt? And why 30-35k intervals when modern cars are quoting 75k or much more? Is it the belt or the car?

[mbouse]

new belt, around the block = reuse
new belt, 100 miles = reuse

anthing else, and I'd buy new.... under $20 anywhere you look. why take a chance?

[pope]

Fiat says to replace every 30,000 miles. That belt actually times the camshaft to the crankshaft. Depending on year and engine mods, you could ruin your engine if the belt broke. Pistons hit valves. Better safe than sorry.
Newer engines are probably designed to be free wheeling if the belt broke.

As to when to replace, I am sure no one replaces it everytime they take it off. You will notice the difference. Slight hardening and cracking means replace. This is one of those owners discression points. If it doesnt look MINTY fresh, replace it.

[wengr]

new belt, around the block = reuse
new belt, 100 miles = reuse

anthing else, and I'd buy new.... under $20 anywhere you look. why take a chance?

thanks guys for the replies. Mike, my personal feeling about it mirrors yours, just wondering what the difference is between our cars/belts and modern. I do believe that there are many interference engines out there. I recall something about one make(want to say honda) where the belt also drove an waterpump? PS pump? anyway whatever it was, they reccomended replacing it along with the belt. Because in the unlikely event it failed the belt would fail resulting in engine damage. But that ws an 80k interval. I also seem to think there are some modern intervals around 100k. So I guess what I'm really thinking about is - are the belts for the fiat still made to an older spec. and therefore inferior to modern belts? Or are they a typical modern belt and nobody has calculated a new more reasonable interval. I agree that the low cost makes it a somewhat moot point. just curious

[jimincalif]

Just by way of comparison, my 93 Lexus LS400 maintenance schedule calls for the timing belt to be replaced every 90,000 miles.

[baltobernie]

I recall something about one make(want to say honda) where the belt also drove an waterpump? PS pump? anyway whatever it was, they reccomended replacing it along with the belt. Because in the unlikely event it failed the belt would fail resulting in engine damage. But that ws an 80k interval. I also seem to think there are some modern intervals around 100k. So I guess what I'm really thinking about is - are the belts for the fiat still made to an older spec. and therefore inferior to modern belts? Or are they a typical modern belt and nobody has calculated a new more reasonable interval. I agree that the low cost makes it a somewhat moot point. just curious

My 3.2 V-6 Dodge also has the "at risk" water pump; I think it is a very commonplace design. The Dodge belt sure looks similar in construction and material to the Fiat belt. Maybe one difference is that the Fiat belt kinda runs out there in the open? The modern car belt covers are completely sealed.

[Tappy]

an idea would be to send a mail to continental or so , they issue timing belt for our fiats too. I wonder what they would tell you

[mdrburchette]

Belts have come a long way since our cars were put on the road so I'm sure we could get more than 30K out of them if we drove them 12K miles a year. Right now, if I were to change my belt at 30K miles, mine will be due to be changed in the year 2035.

[manoa matt]

The typical fiat spider engine, even if well preped will still spew tiny amounts of oil out at oil seals and gaskets. That oil picks up dirt and engine grime leading to acclerated wear of the belt and cog teeth. Maybe Fiat realized this and thought that after 30K the belt would be soaked with oil and grime.

[racydave]

Rubber starts aging as soon as it is manafactured. There should be a time interval also!

[htchevyii]

I was wondering if the reuse warning was because of the tensioner. I know new and used serp belts have two different tension specs. If the spring tension on the FIAT is set for a new belt that will stretch, it could overtension a used belt?

[So Cal Mark]

the difference in replacement intervals is due to the type of teeth on the newer belts. Long life belts use rounded teeth (on the sprockets also) unlike the square teeth on the Fiat motors and most others of that era. The teeth don't shear off the rounded belts, hence the longer interval and a much higher price. OIl or coolant leaking on any belt shortens the life drastically.

[wengr]

the difference in replacement intervals is due to the type of teeth on the newer belts. Long life belts use rounded teeth (on the sprockets also) unlike the square teeth on the Fiat motors and most others of that era. The teeth don't shear off the rounded belts, hence the longer interval and a much higher price. OIl or coolant leaking on any belt shortens the life drastically.

ok that makes sense. I recently found out that my current belt was installed in 1991 - so I guess i'm do