Dave, FBB- Beats me. I do think it is foolish to do a cam belt swap and not use a frequency/sonic tensiometer. On the 550, I assume the frequencies are the same as those on the 575M, since the 550 WSM called for using a less accurate Steiger that measured load. Dave- Is there any need to retension the belts after 1200-5000 miles? The 456-575s maintenance schedules shows the belt tension being reset at 1200-5000 miles when the car is new, so did not know whether that applied to new belts or not. Taz Terry Phillips
My findings show the new belt design to be more rigid requiring different tension settings than those posted in the WSM. I have a full file on this situation and printed out every printed spec from every 'reliable' source. I was not happy with the 'feel' when using any of those spec's. Noted in my data file are tension spec's of 550/575's that were brought to me with belts less than 200 miles old that sang like the engine had a blower on it. Those readings only show what the belt tension was at the time of checking them but the engine was already covered with rubber dust. I have the spec's of the examples where both of the belt drive bearings were at the raged end of their life but the belts were already 3 yrs old. With both of the above conditions I can only speculate what the initial tension settings were and how it was done. Setting the belt tension via the std spring method and then checking those results using the hertz method, adding into that a std amount of stretch based on dozens of examples.... Short answer is I believe the printed spec's are a good way out from ideal for this model in my opinion. Only time will tell if I am the fool for wasting so much time on this but periodic rechecks of the half dozen test mules I have on the road with modified settings show no rubber debris, belt noise or bent valve conditions. Hardly enough to qualify as an answer but plenty to show a trend. The only examples I have found requiring a "Re-tension" of the belts were those with failures of other components leading to that condition. The distance between gears doesnt change in a cold engine, kevlar stretch's very little.... a loose belt is an indication of a problem that needs to be looked at, not something requiring a re-tension. Read between the lines in printed maintainance schedules.... those cars are under warranty and are a liability to the manufacturer.... follow the money. I was fortunate to have an exceptional technical rep at FNA during my dealership time and he allowed me to fix cars that I felt had problems, not bubble gum them through the warranty period. Re-tension of a cam belt.... not for me.
Dave- Thanks for the detailed answer. The factory 575M WSM was published before the new belts were introduced in early 2002, and were definitely made using the old belts. The 612 workshop manual was published after the new belts were introduced (first version in 2003/4 timeframe) and shows different numbers by far, shown below, but they are the sum of two readings of different spans on one bank. From the theory, the belt frequency goes up as the tension goes up, and the 612 would seem to indicate a higher frequency for the new belts compared to the old ones. Since the 575M and early 612 engines are virtually identical except for ECU changes, the latter data would seem to apply to both. Am I misinterpreting the tech data? Or were you referring to using a different type of belt tensiometer? One fo those spans is also shorter and may be considerably higher frequency than the other. Taz Terry Phillips Image Unavailable, Please Login
What if any is the degree of difficulty in changing the belts between these two models? I'm a home wrench guy with a lift & many tools. I've done the belts on my 308 but want to buy a 550/575 and wonder if I can transfer my current knowledge/skills to maintaining a 550/575. Thanks.
All skills will transfer. Access on V12 is easier. I used to nearly have to climb in there to work on the front bank of transverse engine cars. With the 550 I need to lift the car so that I'm not leaned over so much and killing my back. With 308's it was always a pain to pull the studs on the A/C and have the dang thing hanging and always being in the way. There is none of that with the 12's. Also dinking with R1 and R2 points and CIS FI well I'm happy to have modern motronics and OBD2. Also the 308 was really a transitional time from 60's no smog equipment to smog equipment. Smog in those days was an afterthought hung off the motors and just did not work well causing owners headaches and car's drivability problems. Modern smog controls designed in with the electronics are such a breeze.
I know this thread has not had any activity for a while, but I feel it is a good reference. I'm working on the belt service on my 550 and need to purchase a tensioning tool. Taz's reference to tools back in 2011 only has one link that is still active. Does anyone have any recommendations or pro's/con's on any of the tools on this page? I want to make sure if I purchase one of these tools that it will fit the application needed. Thanks! https://www.google.com/?gws_rd=ssl#q=belt+frequency+meter&hl=en&prmd=ivns&source=univ&tbs=shop:1&tbo=u&sa=X&ei=LbB-Te7IBc6JrQHCmeCCCQ&ved=0CEMQrQQ&bav=on.2,or.r_gc.r_pw.&fp=503ef9a58296c9b1
Lots of things have come on the market as this has become a far more used method. Do not get the BTM tool in your link. I have one and think it is a real piece of crap.
I think that he's asking about a Staeger Tensiometer. There was this thread: http://www.ferrarichat.com/forum/456-550-575-sponsored-bradan/299377-staeger-tensiometer-rifledriver.html All in all, a pricey piece of equipment.
The Stager gauge was a disaster. The frequency tools are a far better plan. As I recall Terry found a good one in the last 2 or so years at a good price. In the last ten or so years they have become far more common so the price for decent tensiometers has come down. If a search is done with his screen name and the word tensiometer I am sure it can be found.
I have a Clavis Type 4 available in perfect condition in the case, basically like new, looks like this: Clavis, Handheld Tension Meter, Type 4 - Ansontools.com Some information: http://www.clavis.co.uk/Handheld%20meter%20catalogue.pdf PM me if interested M
