metal-guide -vs- rubber belt = disaster. is it supposed to be setup with a small clearance from the belt to prevent belt-slap , perhaps ?
I think they are there to reduce belt "slap" when decellerating. Maybe they had a problem when they designed the engine,maybe it comes close jumping a tooth,up the top where these are positioned? I dunno? Im sure a little gap there is needed but to prevent what happend there to Jeffs' guide. There isnt anything to locate the guides. When you tighten the bolt,the guide would spin onto the belt(drivers side AU) unless you try to hold it up off the belt when you tighten it. The left will pull up off the belt when you tighten it. Which is the right and left on yours Jeff? The right was worn on yours,meaning passenger side in the US? Because you's have LH Drive??
Jeff,in your pick there of both the guides, Say we are standing in front of the engine,is the left one in the pic(worn one) go on the right side?? And the other,on the left side(drivers side AUS)??
I just had a look in the manual. Yes it does. Do you think what i am saying is correct mate? When they refitted them on the last belt change,when the mechanic tightend the right one,it spun around hard onto the belt? And has worn like that ever since? Like i said,the left side,when tightend will spin the guide up,off the belt,which is why that one is not worn like the other because it was just off the timing belt.
Hope i havent confused everybody with the way i posted this ****! LOL Sorry cant elaborate with pics like you guys can.
OK. In joining this insanity I went back out to my car and pulled off *both* cam cover inspection caps. The guide on my right side was *not* pressing on my belt (just very near to touching it). Likewise, there was *zero* belt residue on the right side. If you'll remember from my posts yesterday, the left had the guide pressed hard against the belt, and there was some belt residue. Then, for completeness, I jacked up the rear end and rotated my wheels forward (in 5th gear, thanks Aussies) after marking my cam belt with masking tape. Examined every tooth. Didn't miss an inch. Lo and behold I've got white "Ferrari" lettering on the belt after all! All of the teeth are fine. Also some sort of "Isoran" or some such (it was upside down and I was uncomfortable on top of my engine) and some part numbers and other writing. Oh, and *another* black plastic post broke off of a cam cover cap (right side this time)! Sheesh. So why do I think that the belt guide/sweeper on my left side is wrong (e.g. belt residue on that side) to be pressed hard against my belt...and perhaps my right side is correct (no belt residue there) to be ever so slightly above my belt? Surely we should use rollers if they need to be hard pressed against the belt, right?!
Miltonian, my guides are both all metal. No black anywhere on them (not even near the lockdown bolt). Yours appear to have a black coating over metal. Just a datapoint. I don't know if it means anything.
I would guess that the coating on the guides is just black oxide, something to keep them from corroding, but I'm not an expert. If these things were replaced with rollers, they would burn up in no time. Not enough surface area for adequate bearings, for the kind of sustained speed they would be turning, and the pressure against them, and the heat, and no lubrication. As far as having the guides turn in the direction of bolt rotation when the bolts are tightened, all I can say is that the bolts are not at all a tight fit in the holes in the guides, so the bolts shouldn't have much effect as you tighten them, and there are no washers/shims between the guides and the halves of the case, and of course the case doesn't turn. The bolt just "clamps" the case halves onto the guides, so the guide should stay pretty much where you put it. I'll have to experiment with that when I button it up again. It's a bit hard to believe that someone jammed the guide against the belt, THEN tightened the bolt, but that's the way it looks right now. Curious. Just to clarify, the guide that had the most wear on my car was the one on the same side of the engine as the alternator (drivers side in the US).
I don't get it. If I order a Hill Engineering tensioner roller (or OEM Ferrari 348) for a 30K service, but use it instead to replace the flat metal belt guide, it will burn up?
There is nowhere near enough room to fit a bearing the size of the tensioner bearing where the shoe is now located. I'm not saying that it would be impossible to fit a roller in there, but I don't think it would be possible to fit a roller that could hold up to the job in that limited space, unless it had an oil supply to keep it lubricated and cooled.
The drivers side(US) one was worn,thought so. I still think that it when it was tightend,it moved around onto the belt. The mechanic didnt realise or check it to see if was rubbing on the belt or not before refitting the cam cover. Thats just my thought anyways. This cool thread has got the better of me,tomorrow,maybe later tonite,if im bored,ill go and pull the covers off mine and have a look also. With my trusty head mechanic(nephew) Image Unavailable, Please Login
ND, I hope that was a joke, because it made me laugh out loud. If my wife heard me, she's going to wake up and strangle me for being on FChat when I should be asleep. Be sure to cover that nephew's ears when you're laying on top of the engine trying to get to those screws.
Curiosity kills the cat they say! LOL I went and removed both cam covers and found the guides to be slightly worn. Its hard to see down where the guides run on the belt once they are in there,but im assuming that both guides were just riding on the timing belt?? There was minimal belt dust in the covers. I checked the teeth with a little w/s mirror(painfully)and a w/s light while my brother spun the engine around for me(jacked up on car stands in 5th ). There was no visible cracks on the teeth/belt. A good thing of course. Im still gunna do the belt mid year or so as its due to be done. I used some long feeler gauges(see pic) and set the guides to have around 1mm gap under them. Worked great!! All the pics i have posted are from the LH side of the engine(drivers side USA). And it was around a 30min job each side(photos included) LOL. The little tacker handed me the 5mm allen keys/socket/rachet like a good boy! He will be getting a double dosage of formula in his bottle from now on Hehehe Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Pap, your shoe was installed backwards!! Look at the drawing - the shoe is supposed to be holding the belt down against the gear teeth, not holding the belt down in the space between the gear and the water pump! If you look at the drawing, it also appears that if you install the shoe backwards, it's probably riding against the case on top and pushing hard on the belt on the bottom. This is really a bad deal. We have more evidence here that these shoes are causing very significant premature wear on the timing belts. I mean, fer cryin' out loud, if the belt is wearing into a steel shoe, and rubber dust is being collected on the inside of the cover, that CAN'T be right! At this point, I'm changing my mind about not wanting to call those upper covers "inspection covers". You can learn a lot by removing these covers! I'll eagerly await an opinion from an expert on this. Image Unavailable, Please Login
This may not be scientific, but I wanted to see what would happen if you installed the guide shoe backwards. I made a photocopy of the drawing, in the same scale, and cut out the shoe, and pasted it as close as possible to the position of the bolt. It looks to me like the shoe would be HARD up against the belt in static position, unless there was a gap between the case halves for the shoe to sit up higher. If you were able to fit a feeler gauge in there, there must be some kind of clearance, or else you were deflecting the belt. Image Unavailable, Please Login
Yeah you this is all your fault. LOL Actually this has turned out to be a very good discussion. We now know that you need to make sure the guide haven't been rubbing on the belt. However we still haven't concluded for sure how much of a gap there needs to be between the guide and the belt.
The guide facing the wrong way would wear down the belt for sure, along with the guide. *tisk, tisk* I tell you, some peoples kids.
You know what?? You are correct in saying that. They were ****en installed backwards!! I didnt even click at the time! That photo i took with the feeler gauges was before i removed the guides. Thats why i said in my post before that when they were in there before i removed them,it was hard to see down there if they were running on the belt?? Ive had the car for 4months now, but the ****heads in 2003 fitted the belt guides wrong when they did the belt! Hahahaha! What a clown show! The RH side was fitted correctly before i removed it,now that i remember. But dont worry lads,they are BOTH fitted the correct way now,with a 1mm gap under both of them. Dunno about the gap for now,but it seems like it is a good estimate to me. It would be good to know the correct spec for it but. I tell ya what!! LOL! Im gunna go beat down the little guy for not picking up on that LH wrong guide installation! Hehehe
Yeah,i did get the feeler gauge all the way in there. It either had a 1mm gap,or i was pushing down on the belt when i put it in there for the photo?? ****s me?? For being in the wrong way for that period of time,the last belt was june 2003,it musnt have been pressing down too hard on the belt in that reverse position,as the guide is not heavily worn??? You would think? Then again,the car has only done around 3000km since 2003,so the belt has only done 3000km too? hmmmmmmmmmmm..............................
Just an update note. When I reassembled the guide shoes and covers onto my car, I set the clearance between the belt and the shoes with a double thickness of paper. When I was tightening the bolts to hold the shoes onto the covers, I checked very carefully to see if the clearance would change (less on the left side, more on the right side) as the bolts turned. In both cases, the clearance did not change at all. So it seems reasonable to assume that whoever assembled it last time intentionally left the shoes in contact with the belt, and the resulting wear on the belt (and the shoe!) shows why that is a bad idea!
You know what? Just you be extra sure that the guide doesn't twist while you're tightening the screw. I would leave the 1mm feeler gauge under it, or the folded paper, or what ever, just to make it doesn't move.
