heinrich

Mark, you know had you farmed that work out it would have been well over 10k .... so, that is really the key to 928 maintenance. DIY.

lmajr1975

hello, the timing belt and v-belts, basically all the belts along with water pump was changed in 2007 in california which i have the receipt, with 33,000 miles on it, so its been 6 years since and i only put 3,000 miles on car, so even though years have passed i believe all the belts should be in good shape and don't just break because its been 6 years - is this correct? i have read that some 928 owners have not changed the timing belt until 60k miles, even over 70k miles and someone still had original timing belt with 100k miles, just wondering on your opinion all, thanks, because of course mechanics will say to change because its money in their pockets but how many years and miles does timing belt last?

Avar928

You may want to start a new thread for questions or check existing ones that are more recent to glean the answer.

Actually check the condition of the belts and check the tension to make sure it's within spec. Check the condition of the tensioner, refill with gear oil as needed. Check condition of the gears.

polecat702

I've been running Gates HTD belts on my Harley's for over 40 years. Same type of belt that's used on our 928. Drive belts on the bike last the life of the power train. The primary belt that runs from the engine pulley to the clutch, last about 20,000 miles give or take, on the later enclosed primary bikes. Open primary bikes last through a couple of engine rebuilds, but most are changed, cause they're cheap. The belt is subjected to more abuse on a motorcycle than it'll ever be driving the timing gears, water pump and oil pump on the front of a 928.

The biggest cause of failure for HTD belts is heat, detergent oil, or a seized bearing on a pulley that shreds the teeth. Detergent oil will cause the belt to breakdown and delaminate.

The belt itself is very reliable. IMHO, it's a lack of proper maintenance of the cooling system, and the oil being checked in the stock tensioner. If a bearing fails, it may break the belt, or shred the teeth, valves hit pistons, gets very expensive. BTW, the belt is cheap, less than $70.00 for a Gates belt IIRC, when I changed everything last year.

syoo8

lmajr: you've posted the same question in three different threads. Be patient, someone will answer you. Post the year of your car when you ask a question like this. You have an '86- as you posted earlier. This thread is about "Timing belt replacement 928S4."

That being said, I don't know if there is a true consensus on timing belts.

If you do a search on Rennlist (don't use the Rennlist search function; use google and type in the following into the search box: site:forums.rennlist.com inurl:928

You will find many disparate ideas. Many people say 6 years and 50,000 miles. That's what I stick to.

You car's water pump has 6 years of exposure to coolant. The timing belt does not necessarily break because the belts suddenly "snap." Rather, they break because of another failure in the system, like a seized water pump, or something rubbing the belt, or a shiny cam sprocket slowly cutting away at the belt.

Do you want to take a risk like that? Do you know what kind of water pump they used in 2007? Did the water pump have a plastic or metal impeller? Was it a new or refurbished unit? Is there play in the water pump rotor? Are all the rollers in good condition? Is the oil pump gear worn? Is the tensioner leaking?

If you do not know the answers to all of these questions, then I would strongly suggest that you change it. Why take the risk?

Gunmetal

Im with Syoo on this one, When I bought my shark it had receipts for a belt change in 2006, but only 10000 ks put on it, I thought about the cost of changing the belt vs the cost of a new motor, and guess what? When we pulled the belt we found an almost rotted through water pump, if in doubt, go fix it, you'll have peace of mind when you do hit the loud pedal hard!

1988 s4 Auto ROW black/black West Australia

worf928

The problem with 928 timing belts is the last wrench that worked on it. Not how old it is or how many miles are on it.

Learn how to inspect your belt system. Do that every year. That way you will know when it is time to do, or pay for, a belt job

69gaugeman

This