Another Dumb Timing Belt Question

[ColoradoSteve]

Well I decided to replace all my radiator hoses ( in the '83 )since I blew a hole in the lower one a while back. Anyway, since I was in the neighborhood and the hoses are off , why not do the belts, too? I don't know for sure ( the PO was extremely ignorant, only had the car 6 months...) but I believe the belts have about 19k on them. I just know from the carfax report when the car was sold and how many owners( 4 including me). The belts still look brand new and I really don't want to mess with them if I don't have to. The question is: if the belts are really old, wouldn't they look worn and frayed? I just don't see the sense in replacing a part that looks almost new. Also, if I do replace them, does the balance belt need to be re tensioned after 1500 mi or just the cam belt?

[Techno Duck]

Old belts typically looked glazed on the smooth side. Other tell tale signs are cracks in the rubber. Just because they dont look old dosent really say anything about the actual age though.

Balance belt and cam belt both need to be retensioned.

[jerry920]

The cost of the belts is very low, the cost of broken belts is very high. I just did mine for the first time ever, and if you can handle a wrench it's not that difficult. Took me 6 hours total from beginning to end.

Belts decay with age, so my vote is to just do them.

[SolReaver]

OK, I had a hard time with this one too... the truth is that the belts don't just wear, they age as well. They can age sitting on the car, parked in a garage not even moving. 3 years OR 30K is the rule I go by. If you don't know FOR SURE do em immediately. I know, I know, It is hard to accept. They probably look perfectly good and may even have the conti logo on them. But keep in mind that the engineers had room for 1 belt in the front of the car but they had to fit 2 belts in there. Consequently these 2 belts are 1/2 as wide as a "real" belt should be. Don't get me wrong, they are tough little guys. But keep in mind that they are holding thousands of dollars of moving bits and pieces from spinning into each other. Consequently they are under a good deal of strain and are in engineering parlance "pushing the envelope" or to put it another way they have a lower "factor of safety". In order to protect ourselves from the omnipresent gremlin of belt failure...944 owners have developed these "standards" over the course of over 3 decades. That is not to say that if you change your belts at the regular intervals you are guaranteed to be safe. Just that more likely to be safe.

Besides, under the cover is a whole new world for you. A world of shafts and seals and tensioners and Idlers and Really expensive water pumps that needs an occasional dusting off, adjustment, and inspection so as to keep the gremlins away. It is a task, nay, a sacred duty of every owner to go there and save his fair damsel from the dragon of destruction. It is what separates the men from the boys and the doers from the dreamers.

Besides, I was too timid to do 5K shifts with old belts. Like I said, a whole new world awaits you. The car really feels better on new belts. honestly. Freshies all around and super in the tank. Your Porsche will thank you On this car it is essentially a re-occuring maintenance Item. Just like changing the oil or changing spark plugs. You can either gripe about it or just get used to it. It is one of the reasons you picked up a car for reasonably cheap that even a quarter century after it was built holds its own against almost anything else out there.

Summation: Do the Freakin belts before you get hurt, check both about 1K or 2k later, then at 10K and 20K. Flip the *****es out at 30K max

[ColoradoSteve]

The point is moot since I went ahead and put the new belts on. Also put in new tensioners and rollers. But the belts I took off looked brand freakin new! I'm glad that I did it though, a little peace of mind is worth a few bucks and a few hours labor.
I did manage to get the new cam belt on without removing the crank sprocket( thanks to one of your earlier posts SolReaver , you described the process, worked great!) You gotta wonder about the whole engine design and why they had to make it so difficult to change and adjust a simple belt! Thanks for the advice, guys!

[SolReaver]

You did the Warm Sudzy belt trick?
Or did you just snake it around carefully?
Ok, give me the details. what did you replace and what did you save for next time?
Please remember that if you don't do do everything by the book IMHO you really gotta stay on top of the situation by inspecting on a regular basis.

How did you tension the CB? The BB? Do you have "the touch?"

[ColoradoSteve]

Sol,
I just pushed the cb in ever so slowly ( these belts are sacred, I know... ) until it was seated on the sprocket. Replaced all tensioners and rollers. As to tensioning the belts , well, I had the engine at TDC and used the 'cricket tool'. Started the engine and decided by the whining noise that the belts were too tight. Backed them off a bit and then they were too loose. Made one more adjustment and then the engine was purring like the proverbial kitten. I know it's not according to the rule book , but it's my car and I'll be damned if I'm going to spend $500. on some special tool that does the same thing I can do with my fingers! I drove the car about 10 miles to make sure everything was working, runs and feels great. I know too tight a belt can cause waterpump problems but I'm feeling like the tension is just right. Also assume that in a few thousand miles the belts may stretch a bit and have to be tightened. I will check. Let me say that I don't advocate anyone doing this procedure the way I did it. I have a lot of respect for the master mechanics and their methods, it's just that some of us out here have to fly by the seat of our pants! Viva la 944!

[SolReaver]

Steve. You did the job. The cricket is ...OK... I still think the best way is by feel and to listen to the belt with the engine running and the covers off. Don't feel bad if it takes you a few times. Sometimes it takes me 4 or 5 times. Ya gotta be picky and the CB idlers are really sensitive. The tools confuse me to be honest. If you aren't doing anything with the old tensioner and or rollers, I would like to use them for life cycle analysis and a new tensioning tool I am working on. PM me I will pay 4 shipping.