360 - Hydraulic Tensioner Replacement Interval

I’m also curious about the replacement interval.

 

I don’t recall seeing any recommendations. I did it when I changed the belt/rollers after taking possession of mine. It was at 17y/36k miles.
I figured it couldn’t hurt and should be good for another 20y
I guess YMMV…


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I’m doing it during this current major and plan to every time I do a major. Cheap insurance IMO.

 

I would use your own discretion. Ferrari neglected to put changing the coolant in the service intervals after all. Ask anyone with a heat exchanger failure how well that went.

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I ordered replacement tensioners today. The reason is twofold.

1. The right side tensioner looks new and the left looks original. For some reason only one was replaced. Things that come in pairs should be replaced in pairs.

2. I checked the frequency of the belts and the right one was within spec but the left was way low. The mismatch makes me think that the left tensioner is weak.

I could probably get away with changing just the left one but they're not that expensive.

 

I have my tensioners changed at each belt change. The added cost is not significant compared to the overall job. I use Hill Engineering parts.


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There are tensioners and there are bearings. The tensioners are OEM and the bearings, which the tensioners act upon, are typically Hill Engineering. Do you replace both bearings and tensioners?

The bearings are about $300 and the tensioners about $900. I replaced mine because I think one is bad. I replaced the bearings because I have OEM and wanted the better HE ones.

 

Same tensioner design used in 355 and many 355s are driving around with original tensioners. The 360 had a design flaw on the left side and they broke one of the mounting ears off. They have undergone at least 2 redesigns on the left side only. Every 360 should have the latest left bank tensioner installed.

Because of their design if the belt is properly installed in the first place and you have a complete failure of the tensioning function it will only result in a rattle. One sign replacement is needed is if it regularly rattles at start up from the tensioner. Engines regularly rock a few degrees backwards when shut down and this will partially collapse a perfectly good tensioner so judging them by belt tension during belt changes is an invalid test of their condtion. I have seen 360 engines worn out and still had perfectly good right bank original tensioner. Like most parts on the car, no life span is dictated. Its up to the judgement of the mechanic.

 

I had a weird rumble (rattle?) that seemed to come from the left side of the engine. Before I checked the tension, I rotated the engine twice to reset the belts and the tension was way low on the left side. The left side is the original tensioner too. The water pump bearing looked beat and the seal was leaking too from an improper installation last belt change. I thought it might be the water pump making the rattle. It only happened around 1500-2200 RPM's, and only after the car reached about 100F temp. To be sure, I'm replacing the tensioners too.

 

Waterpumps perish from not using a tensiometer to set belt tension. Very fine line between tight enough not to have belt slip and not overloading the pump bearing.

Tension called out for in 360 manual was updated because it was not tight enough and after a few miles they started slipping.

 

There's also the dance between the power steering belt and the water pump belt as one offsets the other. With both set properly, there should be little sideload on the bearing. My bearing was fine but the seal was leaking.

 

Very easy to modify existing mount to take the alignment dowell. Have installed many and never replaced the mount plate.
Even without the locating dowell which is being used for additional shear support it is a better, stronger tensioner so it is an upgrade even if you follow factory instructions to remove it.

 

Can you verify the correct belt tension values as I have a few different values and want to be sure I'm using the correct ones, thanks.

 

How do you determine accessory belt tension?
https://www.ferrarichat.com/forum/index.php?threads/How-do-you-determine-accessory-belt-tension%3F.548990/

I’m no pro, there are a number of threads on this, above is one. Gather your information and make your decisions on the frequencies you use.

 

Hi Guys,

Got my F355 back from the major service in Italy and this is what it sounds like. Amazing really. And this is after sending it back already once I got it back from the service initialy. I was wondering, however, how exactly does the tensioner apply tension as it doesn't seem to be touch the bearing. Apologies if it's a silly question.

Cheers,
Martin