Timing belt(s) issue yet again...

Ferrari's pre 360 service interval was 5 years and 30k miles in the US. It was even shorter in other countries.

If you like 9 years and 52.5 k miles knock yourself out. I buy a few hundred more valves every year and I'll get a free trip to Hawaii from the valve companies.

 

It was never dealer policy, it was Ferrari policy and then only prior to 2002. In 2002 and 2004 the policy changed for all belt drive motors down to 3 years and 30k miles.
Ferrari manuals, shop, owner, and otherwise say a lot of things, some of it true. TSB's are a better source, but then people tend to ignore inconvienent truths.

 

In theory what Ferrari printed may have been correct prior to various environmental factors as well as other factors.

Manufacturers frequently make statements then subsequently change those statements.

In practice, the wise advice of very, very few knowledgeable persons such as Rifledriver would be adviseable to follow.

As he said, the valve companies will send him to Hawaii for buying more valves.

I'd suggest you rely on Rifledriver's advice as I (and many others) do.

 

Tensioners are the problem as posted here 1,000 times before. Not the belts. Mostly a big deal on flat 12s and 355s. I saw a 308gbi that belonged to Vince C. lock up a tensioner just after a service where bearings were not replaced (and mechanic missed TDC). Belt skips over teeth and quickly wears out grooves. Makes alot of dust. You are right about he belts themselves. You can bearly cut them with a knife. But, when they are left in certian conditions, they can break just by bending them after about 12 years or so. I saw the belts that came out of Marc's TR (Atlanta '85 model). Four bends would break them again at will.

 

This subject have been beaten like a dead horse. Steve and I just pulled his engine and nearly died when we examined the tensioner. It was quite clear that the belt was getting ready to go. Delaying a belt server is playing russian roulette with an automatic.
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Something to keep in mind is the improvement in the technology / quaility / manufacture / materials of the belts over time. When Ferrari first put cam belts on their engines --- I believe this was around 1975 with the first 308s and the early 365GTBB Boxers --- the durability of the best belts available at that time was no where near what is today.

Especially, after Gates and TRW began to make aftermarket belts for these engines, the expected longevity of belts went up. Just about every high performance OHC engine out there since 1980 or so uses belts, and their recommended change intervals are nearly all greater than those of Ferrari.

That said, it is certainly possible that the design of a Ferrari valve drive may be uniquely hard on belt life. Also, most Ferraris are expected to be driven hard (high revs) so one could expect a reduction in belt life. Since cam belt engines were new technology when introduced, it makes sense that Ferrari would err on the side of caution and recommend overly conservative change intervals, as well.

The bottom line is that all cam belts on any engine should be changed at the same time ---- "when they need it". And, frequent inspections will tell you when that time is approaching. However, especially with the 308 engine family, it is often early tensioner bearing failure that causes the problem, rather than belt failure --- and that is very difficult to predict by inspection.

In the end, it boils down to each individual's cost / benefit analysis ---- the consequences of belt failure on a Ferrari engine are severe and $$$, and the cost of belt / tensioner bearing replacement is not too bad. So, for some folks, a habit of premature belt servicing makes alot of sense. For others, perhaps it doesn't.

As a baseline, 5 years or 30K miles is a good place to start. Personally on my own cars, I've changed some earlier, and I've changed some later. Up or down from there is your call weigthed against what you believe is acceptable risk and what are reasonable maintenance costs.

Overall, I think we, the Ferrari community, change belts too often --- but, I'm not prepared to say that is a bad practice!!

 

PAUL ---

I'm not disagreeing with you or saying that bearing is good or bad, but I'm curious... What else did you observe which led you to diagnose bad tensioner bearings? From the picture, surface contamination / corrosion / belt residue on the contact surface doesn't say much about bearing health, and is quite normal.

 

Service recommendations were different in the 80's and early 90's for the US as opposed to Europe / ROW. Working at the dealership we strongly suspected FNA wanted the timing belt replacement to fall outside of the 5year / 50,000 mile federally mandated emission warranty (which in early days was open to, shall we say, creative interpretation...).

BTW, and this has no doubt been noted here before, 308 QV's came out with a substantially stronger / beefier belt than had been used on the 2v cars. This same belt type was also used on TR's. As I recall Pirelli made the original belts and Goodyear produced the 4V belt.

At the dealership I worked at, I do not recall ever seeing a broken belt till the dreaded 348 came out. I've seen lots of very slack belts, I've heard noisy
tensioners, and I have seen belts brake from external debris (cam cover nuts lost during a service!) as well as teeth stripped from seized cams on early 308's from a lack of lubrication.

 

It's just like buying insurance. It's a fat waste of money. Until you need it, then it was worth every penny.

 

That's my belt tensioner that Paul ("PAD") posted a couple of replies above. You're telling me that the condition of that tensioner is normal? I'm no expert, but I've seen a few of these with miles on them, and they don't look like that. We have not removed the tensioner yet, so we have not inspected the bearings, but looking at the bluing on the metal, that is usually a sign of overheating, and the surface of the belt itself is very badly skuffed up. That would lead me to believe that the bearing was dragging.

We have not removed the front cover yet, so don't know what the front one looks like. I may do that this evening and will post a picture for comparison. Also, I started a thread on the 308/328/Mondial forum with this picture and asked what folks over there thought about the condition of the bearing. I'll be interested to see what gets posted.

 

Dave,

The reason that we are doing the complete service on Steve's car is that he just purchased it and it was not known when the last service was done. The car as 35K miles, but after we discussed the pros and cons of what should be done, such as change all the hoses, check the cam timing, change to an Electromotive XDI, change the water pump, and basically, clean up the engine compartment, etc. we felt it was best to yank the engine.

Regarding the tensioner, when we pull the belts, we'll examine the bearings to see what shape they are in. You said that you have seen the residue on the tensioners before, however, I have not seen this on any of my 308s. I was suprised to see how much rubber was on the tensioner.

Having been through the effort and expense of an engine rebuild, replacing the belts and tensioners is peanuts, both in time and expense.

 

Changed my belts recently, the belts had just under 3 years and nearly 15K miles later. And the belts were still in as good as new order to look at with no cracks or disfigurement. I replaced my bearing anyways for no other reason other than they are relatively cheep and there Hill engineering units to boot. But for the record the old bearings were also in great working order.
Dont really know what determines a good belt from a bad belt. I guess its a roll of the dice.
The pictures bellow are of my old belts (top one) and my new belts bottom.
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Replacing old tensioners is a good idea but I see nothing in that picture that makes me think it is on the edge. Rubber transfer is very common as is wearing off the cad plating.

 

I have had a number of older Ferraris and the owners manuals always recommended replacement right after the EPA required life for timing system parts ran out. Then they sent notices to dealers telling them to replace in 2-3 years. I had an 85 308 where a notice was inserted into the manual to change every two years. It was a factory printout. I think the service intervals in the service booklets were made simply to comply with EPA regs. For those who want to follow the books, I know Brian will keep valves in stock for you!

DAve

 

There you go letting logic and truth get in the way of the 100000000000000000000000000000000000000000000000000000000000th perfectly good timing belt thread.

 

We need an Al Gore film on timing belts.

 

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Or maybe a taxpayer funded government study or I know.......Lets do a poll. Can't have been more than 50 or so of those.

Lets hear from someone who has had one break if such person exists.


Lets hear from someone who has gone 20 years just to find out his old belts are perfect and now thinks it's all a conspiracy by Ferrari mechanics.


Lets have a poll on 355 exhaust manifolds to see if they really do go bad.


Lets have a poll to see if Elvis was abducted by aliens.

 

Paul / Steve ---

Absolutely, replace the bearings if you have any doubts. Especially if the service history of this vehicle is unclear. I wouldn't even bother wasting time checking them out on the bench --- if you want the added piece of mind, and have it in your budget, just replace them.

Alot of folks here on F-chat don't have the expertise level that you guys have. So, in deference to them I merely point out that if you pulled the belt covers on (10) random 308's, probably at least 2/3 of the bearings would look similar to yours --- and most of those would be in fully operational condition. So, the average DIY'er might see that on his car and then go waste money on a belt / bearing change --- since any reputable shop would not simply do this service without also, checking / setting valve clearances, setting cam timing, etc., the cost becomes alot more than the price of belts and bearings.

Now you have the advantage of actually looking at the bearings, and I only have a picture to look at. From the pic, I can't see the surface "bluing" / burning you describe, but that does not mean it is not there. I will say this, however, if the contact surfaces of the bearings have in fact been heated to the point that they have actually been "blued" (whether due to internal heating or from the friction of the belt slipping), it is next to impossible that your belts would have not been shredded. The heat needed to discolor the steel far exceeds the survival temperature for the belt material --- even brief contact with metal that hot would damage a belt to the point that it would snap very soon after.

As for the discoloration, other possibilities exist. Many contaminants from soaps (car washing) or chemicals (belt dressings) contain dyes which could cause discoloration on metals. The belt covers on 308 engines are nothing much more than rock and heat sields. They offer little protection from fluids and aerosols getting on the belts.

As someone mentioned (maybe it was in the 308/328 section?), never use belt dressing on these belts. This goes for all toothed cam belts --- all belt manufacturers and factory service manuals for all makes warn against it --- it erodes the belt material and leaves deposits in the tooth roots which can cause gear (tooth) jumping and premature belt weakening. This stuff is intended for smooth, accessory equipment, v-belts only --- always has been.

That said, I've seen alot of this crap stuck on cam belts / pulleys --- even when serviced by "so-called" professionals. A detail people often overlook when changing their belts is to thoroughly clean all the pulley teeth and contact surfaces of any type of residue. This is a tedious PITA job, but trust me, it's a detail that can make a big difference.

Good luck to you guys --- looks you are very thorough in your approach, and that's never a bad thing...

Cheers.

 

Here are my tensioner bearings and belts. Taken from my recently purchased '78 308 with 42K miles. A "30K mile service" performed in 2003. Records are informal so I cannot make hard claims. I also don't have the experience to judge the parts on their merits. That said, I believe the belts were replaced in 2003. The tensioner bearings -- don't know. The cam seals -- I think not.

Seamus
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Just change them when they break..no big deal..sheeesh...you guy and your over annalyzing of everything...

 

I just had mine changed on my 328. The tensioners looked better than yours as the outer contact surface was clean. The belts also look okay, but I have not seen a new belt yet. Probably a good idea to get that service done. Now you can drive that 308 and not worry.

If you search around this site you will find stories where people have gone years without a problem and other stories where one tensioner was frozen (not turning) and the owner was very lucky he had it check out before a long drive.

Oh and waiting until they break is just wrong. If the belt(s) breaks, you will be bending valves and cracking pistons. IMO don't take advice from someone who doesn't own a Fcar and if it sounds stupid, it probably is.