Ok Gentlemen and Gentlewomen, this is the second time I've melted a belt in 2 years and it happens eveytime I go through a big puddle. The belts are made as you know from plastic which is shiny and nasty with no reinforcement in at all. Now unlike normal belts that if they slip a bit they are fine and when they get wet they actually grip more, the Ferrari belt slips more when wet and then simply melts. Today I was going to work, pouring with rain went through a puddle, belt squeeled for 300 yards and poped, battery light came on. I'm going to have tofind a belt that is 'normal' and not made from this ToysRus nonsense, so if you good Folks have any ideas that would be fab. Now I know you will probably say do it up tighter and that others have had no issues and thats fine, but I don't like putting lots of side load on the water pump by having it tighter than a J-Lo s knicker elastic. Anyway just can't rely on it not to leave me stranded at any time and if you didn't notice it had gone, then goodbye head gasket and hello expensive rebuild. Regards Bell
Hi Bell, If you decide to change the cam pulleys as well to some of those alluminium ones that several others have done, it would be great to see one of your videos on the process. Good luck
Hi John, no alternator is fine and so is the water pump. The belt is slightly looser than it should be just because it feels so damn tight when in spec which does put side load on things. I only do it tight enough not to squeek but on the 2 occasions it's got wet it does squeek and ping it's gone which is ridiculous really. I mean if it was a decent belt it should be able to squeek a little without breaking. Also belts with cloth reinforcement actually grip more when wet. Anyway I'm on the hunt for an upgrade....
I bet you only have one belt for your wp and alt. That is the problem, not the puddle, and you are not the only one with this issue. The only fix is to change to a two belt set up that Ferrari eventually did as well by late 85.
Bell I bet you are talking about the Gates Polyflex belts? My last a/c belt lasted 1'250 mls. That is not even 2 months for me. And yes, the pulleys are clean, line up, the idler has new bearings, the compressor is working normally and the belt was at the right tension. The last one busted in tension. Usually, not this time though, it takes off the alternator/water pump belt in the process of disintegrating, leaving me stranded. Firstly, I am not sure if those Polyflex belts are to original specs or just a current-day replacement with the correct dimensions. They are not really for automotive use according to Gates. Would any of the knowledgable experts here actually know what was put on those cars by the factory? Like a part number/name or the like? The owner's manual is not giving any clues, the workshop manual neither. Secondly: Polyflex belts are 60° chamfered, normal cloth-type v-belts are 40°. Theoretically, no normal v-belt can replace it without modifying the 3 pulleys' grooves. I haven't actually checked the groove sections of all three pulleys but will do next time... Anyone knows more re this topic? Thirdly: Modifying the groove on the idler and compressor is a "simple" machining job. The crankshaft pulley however acts as a harmonic damper too as far as I know. I am not sure wether modifying its mass would be detrimental to the engines longevity. Would an expert please help?.... I need A/C in Hongkong! Fourthly: I have bought two normal v-belts ("Gates 6217MC, AVX10 x 925 La" and "APSODrive XPZ x 900") and will check whether they mount and if so, last. I have also found Polyflex-spec replacement belts by Bando (=exactly the same dimensions). They haven't been delivered yet but I will put them on to see if they are up to the job. Thanks for input!
No idea on factory original belts mfg. Gates is the norm, though I'm sure continental carries them as well. I'd have to dig up the dwg's for the belt size to check the sheave angle. for those that don't know the belt 'rides' on the sheave or 'side' of the pulley not the bottom. the pulley sheave is a convex curve so that the belt always has a positive face that centers to the pulley groove, if that convex face wears down as it does on aluminum pulleys then you start to get belt problems. Modifying the mass of the damper will not cause any problems for the engine. however there's not alot of material to 'cut' new grooves, being a cast iron piece the wear is going to be on the other pulleys first.
1'250 mls - no slippage, bust in tension when the a/c kicked in on the freeway, dry hot day: Image Unavailable, Please Login
Many thanks guys for your input here. I could crank the next one up real tight as in the book but I'll be pretty annoyed if the water pump fails or the alternator as a result. Yes a brand new alternator and water pump should take the load no problem but mine are fine but old and so they might well fail. It's a bit like me track racing my car, to do it when it was new would have been fine, to do it now and it would go bang. My mechanical sympathy tells me that doing that belt super tight is gonna couse a problem, hell even my Lotus power steering belt isn't that tight. It's interesting afterburner that your belt has reinforcement in it....mine has none so there in may be my problem. Let me know how you get on with your belts, I'm going to look for an alternative also I think. All the best Bell.
Oh yes what size is it, my belt goes crank, water pump, alternator......saves me going outside to measure it ;-)
I have a U.S. 1983 308 QV. I just melted my alternator belt. I only have one. Runs both the alternator and water pump. Does anyone have a good part number for this belt? I searched the cross-reference thread and found two: Gates 7208 and 7261. I'm so confused!
Those fit. 7M1000 for the alternator and water pump (7mm wide x 1000mm long) 11M925 for the a/c (11mm wide x 925mm long) The original toolkit contains both belts... Image Unavailable, Please Login
Yes many thanks, I will let you know my solution. I may well maladjust the new belt to make it squeek and see how much abuse it'll take just to be sure it's an upgrade on the old one. I will keep a spare also. I suppose the main worry is if the belt failed and you didn't notice the light on a sunny day say, then you'd cook your engine within 2-3 mins. I'm thinking of making a low oil pressure, high water temp buzzer that sounds in the event of a problem, because you can't watch the gauges constantly... Will post up the circuit and a host video when I do, it's a cheap insurance.
You'll see the light. I did, clearly in daylight, back when mine failed about every two years before I converted.
Hi Guys just reread my post, what I meant to day was that I'll stick with the single belt setup for now, but find a better tougher belt...
That sounds like an ideal opportunity to repurpose the nanny seat belt buzzer, assuming your Mondi has this.
No I've never heard of that......however anything that vibrates the lower regions whilst driving sounds very entertaining. Does my girlie get a buzzer too?
To two belts instead of one. Throwing belts was a big enough problem on some of these cars back when they were new that Ferrari issued a service bulletin to dealers and offered a conversion kit to change from one belt to two. The design was eventually incorporated into the model in late 84 I think. Maybe early 85. I have one of "those" cars. Jan 84 build. I sourced a kit (forget trying to find one now) and installed it about 10 years ago. No problems since. 100% cured.
