1998 550 Maranello "sorting" thread--DIY

Yes, the "new" belts have a higher tension specified for them (same as 612).

Taz elaborated on this on another thread.

Basically the logic is that the new belts are of a different material/construction and require more tension.

This applies to all belts of the V12 line (456/550/575/612).

Please take as many pictures as you can!

Thank you so much for your detailed documentation, it will be very helpful for many members, including myself

 

I am sure you will get the correct answer very soon.

Overtighting can cause premature failure on the belts, bearing, etc.

On the Porsche 944, the best way to know if it was right, was by listening to them.

You mentioned that you "greased" the tensioner, where exactly did you apply the grease, on the spring assembly?

I have yet to understand what is there to be "adjusted" on the belt tension, if the tension is given by the tensioner spring...I await your pictures to rid me of this mystery

 

The last two I did that were presumably set to the factory tensions on the last belt replacement had a great deal of rubber debris packed in the front belt covers. One was 3 years and 2000 miles and the other 6 hours and 135 miles.

 

And with respect to setting the right tension on the belts, how exactly does one do that? Thanks. Frank

 

Thanks for your explanation.

So it seems the "factory" setting may be too much? I presume the debris is a sign of overtightened belts, especially after only 2000miles and 6 hours for the other...

 

Feel for any play in the bearings behind the belt drive gears. Look for grease being thrown from these bearings. When I find rubber debris, I find these bearings are near....

 

Dave, are you referring to items 11 in the figure below?
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Thanks for the quick and very helpful response. I appreciate it. Frank

 

Pete, with all respect, checking tension the way you discribed is a static tension is not the way WSM documented. They discribed as you do at least two rotations then measure the tension if it is correct then tighten the bolt. Otherwise rotate again to reach the optimum tension. In this situation I assume you distribute the tension evenly across the whole revolution. Correct me if I am wrong. Sark

 

Pete, I agree. Rotation of crankshaft supposes to set the spring to ideal tension then tighten the bolts and recheck the tension. Doing the way you described is not going to tune the belt tension between the cam and timing gear, and few rotations it will. Now what are going to be the readings in either way you are the man to tell us? Sark

 

Pete, hopefully thats it. Lock the cams. But see what Dave has to say. Sark

 

This is correct. This is the reason years ago I was bashing a bunch of 308 guys who were using cam locks and not timing the cars. You must equalize the tension on the differnt cogs in the driven direction.

 

The sky is not falling! You are doing a great job just take your time. I'm not Dave nowhere close noway nohow. However, you can't validate a bearings condition by how much grease it throws. All bearing throw grease and you can regrease bearings too even sealed ones. The hand is a very powerful thing and if you do have the bearing professionals to hand a bearing to for an opinion, or the machines to do it yourself, you can very effectively feel the operation of a bearing. But it is usually just cheaper and faster to replace the thing than worry about it. So if you worry just swap it. Some people have ham hocks for hands and should not be wiping their own behinds. I can easily feel a thousandth's of play.

I also set timing belts by hand for the last 30 years because I could never get my hands on a steager tensiometer and there is no factory spec for the 550 belts sonically. We are guessing that the 550 should have the tension of the 575 with the new kevlar Ferrari branded belt. Taz gave us no real information. He is a great researcher but never turns a wrench. He made some conclusions and is a guy I respect but there is little in his post on the subject that I would risk my engine on. I would not even use the 575 sonic spec if "my hand" told me otherwise. I would use the 575 spec "if" it "felt" really close. I think even Dave has not come to a final HZ spec for this car. I think Dave has many cars out there with various specs and watching to find the optimum point, testing in real life. I don't even own a HZ meter and quite frankly Dave got me all parnoid about the 550 belt tension. So periodically I pull the cam covers to inspect the belts. I've done this about 3 times over about a year or so and everything is just fine with my hand tension job. I don't recommend it be done that way I just have alot of experience doing it that way and I don't own the tools or have the specs to use the tools. Anyone who can time their motor can get the covers off in less than an hour so you could make it a part of the oil change. I routinely when I change the oil examine the entire underside of the car looking for shock leaks whatever. It does not take long and you got to wait for all the oil to drip drip out anyway.

Dave also might have those cogs available for purchase or you can weld them back. Your local welder can TIG them for less than 20 bucks. Dave is really on to something with his improved cogs. They looked just fancy anodized but his coating does so much more to enhance belt life. Next time I get my car apart I'll be buying those if he has them for the 550. Your cog failure could be a blessing in disguise.


Oh I forgot...don't panic on the timing. Just know where TDC is and mark it with nail polish just as a quick referrence but always verify it dead nuts with the degree wheel/gage. If you screw TDC everything else will be screwed. Set cams to the marks and nothing will hit. Then time the motor.

Sure the car seems like a money pit but it is going to run awesome. At the end of this thread I'm waiting for your last post on this sorting:
"Thanks Dave!"
"I could not have done this without you"
"It was worth every penny and all the sweat"
"My 550 runs awesome!"

 

Can someone please clarify, are the driven gears NOT lubricated by engine oil?? They are just greased??

 

My compliments to Pete for his tenacity, few would go this way. A keen eye just saved an engine, those little details really do matter. One needs only to ask Daniel, Chas, and numerous others what happens when the fence comes completely off.

""I think even Dave has not come to a final HZ spec for this car. I think Dave has many cars out there with various specs and watching to find the optimum point, testing in real life""
Right again Fatso. I have closed in on where I want to be and now have it down to a very narrow range. What I do know is Everything changed when the new belt came out, you must follow the TSB, not the WSM, and I have reason to question the TSB. Thats just me and as I was taught decades ago by people far smarter than myself...... who the hell am I to question a Ferrari engineer. I also agree with FBB regarding the 'feel' of the set belt. I have done many hundreds in my 40 yrs and still trust the hand more than the meter. The meter is there so I can be consistant in my testing and take it to a level above "About That tight", that doesnt cut it in this business. Lord Kelvan stated "If you can express it in numbers, you then have the begining of knowledge"... the old cuss was right, go figure.

This is a very special bearing and available from Ferrari alone to the best of my knowledge. It is a very stout bearing and in normal service should near outlast the car. With the tensions some of these belts are being set to now..... imagine the side load on that bearing if high 'C' can be played on the belt. Piles of belt debris now a somewhat common finding under the covers... I am not smart enough to recommend a direction, a tension, a host of things but I know I am changing things because this is not working. Once the belt drive gears are off there will be other signs that will tend to point a direction to follow. Last time I stated that there was a belt problem here I got slammed for pointing out a problem where there wasnt one. If you feel that way, please ignore this post with my apologies. Sometimes a sample group of more than one has its benefits, been here a number of times and because folks dont hear about it doesnt mean it doesnt happen. There are a number of things I have learned not to talk about here..... no one likes a target painted on them, this is but one of many.

Now Pete has to find out why the fence came loose, that didnt happen on its own, now the detail work starts. Time to really clean up the work area, get some bright lights, good straight edges and get comfortable. These are the costs of the 6 hr major services I read about here. Sometimes 'cheap' has a cost. Moving the engine from TDC is now of no concern as the cams are not in, all the valves are fully closed and there is nothing for the pistons to make contact with. Getting the degree wheel back to correct will be the easiest of what lies ahead, dont worry about that.