Chuck Schreiber

3rd Coast 2007.
We went to Motorsport Ranch outside of Ft. Worth for a track day to kick it off.
Good times!!

mickster

My 2006 Honda Civic Hybrid is 6 1/2 years old with 80,000 miles. The serpentine belt does very little work compared to a 928 and with far less torque. Lifespan is 80-105,000 miles.

Just had it replaced as it looked like dry rot was setting in. Mind you the car sees a lot of miles in all weather and salt--but also remember we all warn each other that tires over 6 years old should be avoided for the same reason.

I would not keep a belt for more than 6 years regardless of mileage-regardless of belt. Mine is 3 years old and being changed next month after a few thousand miles.

voskian

The 91 GT I just picked up had 24K miles and all repair docs showed belt was never changed and it was the original TB. When we pulled it, it looked good, no cracks it dry rot. All the rest of the drive belts same way, looked new. Changed out the TB, Tensioner and WP, as well as changed drive belts also and should be good for about 5 years. Gears looked new..

mickster

But that car was stored in a temperature and humidity controlled garage, correct?

voskian

Mickster...yes, temp and humidity as well as radiant heat floor!!

The tires on the car were from 1995 and they didn't have any cracks or dry rot. I actually drove the 70 miles home on them and only had a slight shake at around 65 MPH. They are off the car now, but look like new sitting in my garage.

So far about 650 miles clocked on it since I got it and no leaks anywhere!!

Fixer

My '83 has 63000 miles, the belt was done at 33,000. I believe that as a US car no damage would be done to the motor, IT THAT TRUE?

The belt change was like 9 years ago i have all paperwork. I won't rev it hard until i do the belt.

I just bought the car this past July and have owned 911s for almost 20 years.

I really enjoy the 928.

The belt looks fine, but it's always on my mind.

I am trying to get it back on the road after paint restoration.

Mongo

The last few posts indicate that if cars are stored inside in a somewhat stable temperature, does that mean the belt lasts longer? I took a look at mine yesterday when I took the intake tubes off and shoved a flashlight down the inspection hole. There were no cracks on the belt, but obviously you can see the factory Conti label worn as a result since passing through the rollers. The belt looks okay still and I'm not driving the car that much. I think when my first DIY belt job comes around, I may ask for some local Rennlister help on here.

Lizard928

Prussia,

If US engine and no engine modifications or big carbon build up that is correct.

Mongo,

If your belt says Conti on it replace it with Gates regardless of age!

GregBBRD

Looking at the back side of the belt doesn't tell you very much....

dcrasta

Take an old belt and twist it. Look between the teeth. You will usually see some degrading or cracking. When an old belt fails, it doesnt 'pop' .. Usually the teeth seperate from the belt. This more often than not occurs not at High RPMS (where the momenteum of the rotating parts is high.) Its usually at startup or when you pull off (changing enging speeds from 0 -800RPM or idle to 3krpms). That feeling of a dead engine followed by a spinning crank is not one that should be experienced. I had a timing chain break on a inline 6 chevy in highschool. Tried to start from a light on a hill and that was that. Age matters in any material that can deteriorate over time.

Mongo

I'm sure it doesn't. Either way it's going to be replaced. I do have one question that I could never understand on these cars. I've seen John Pirtle's DIY several years back as well as some posts on here about it. Why must the engine be turned to 45 degrees when the belt is removed and replaced? Why can't it be set at TDC during this process to ensure that the engine cam timing is set correctly? Is it just because one can rotate the cams at 45 degrees to align them (of course when the 45 degree mark is painted on each gear)? I have pasted in John Pirtle's link below.


http://members.rennlist.com/pirtle/tbelt.html

Mongo

I remember the first belt that was replaced on this car and my mechanic showing me that it was OLD. The top was also more worn than the belt in the car. Bending the belt backward in front of me clearly showed cracks between the teeth on it.

Cosmo Kramer

At 45 degrees the cams don't have the valves open so there is no risk of having the cam gears move once the belt is removed.

dcrasta

I believe the 16V can be done/are done at TDC. Like Kosmo said, the 32V have pressure on the cams at TDC and this pressue will rotate the cam once the belt is take off at TDC. 45deg no valves are open and only 'slight' pressure is on the cam (I believe the passenger side cam will try to advance on you if you do not pay attention you will end up 1 tooth late.. ).

Mongo

This makes a lot of sense now. When I begin my project I will make sure I get everything lined up at 45 degrees before pulling the belt off. I am still debating on getting a Porkensioner since this will be sort of a budget TB/WP and I have to allocate the funds to a new Laso.

On a side note, if I hijacked this thread, sorry!