355 hydraulic tightener replacement?

I'm doing the engine out belt and bearing replacement, what is the thought on replacing the hydraulic tighteners? At $350 each, I'm not looking to increase my costs but are these a high fail or item that regularly years out? I dont hear much discussion about them being replaced.

 

Did you take notice of how the belt/tensioner looked before you disassembled it? If there was no gap at all, I would replace them. The newest 355 is 26 years old.

 

They should be stamped with a date. If they're not, they're pre 1997 iirc as that's when they started putting the date on them, and definitely should be replaced. When I did my major in 2023, I put new ones in as they had no date meaning they were the originals to the car (so almost 30 years old). They were fine but that's an easy proactive replacement. I'd say if they're over 15 years old, probably worth replacing but I don't think there's any official guidance on that.

 

I replaced mine two years ago when I did the engine out. They were 10 years old.

For $700, I decided I'll replace them on every engine out cycle I do.....but I run seven years between service intervals unless something else requires a removal.

 

Mine were from 97 I changed them.

 

FTW

The only problem is seeing the stamping easily...


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Are the new tensioners quality or is this another thing Ferrari sub'd out to a company that sub'd the manufacturing to a Chinese sweat shop?

 

If they're garbage, I haven't heard about it. We sell a bunch -- here's the history on 157356:

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I haven't pulled my engine yet so not ble to check the dates. The engine out is early next month.

If not original ('98 355) I suspect that they are at least 13 years old or more. They may have ben replaced in the engine out in 2012 just before I bought the cr but I don't have the complete parts list. Haven't been replaced in my ownership.

 

If you're planning more than 5 years between majors I would replace them (I personally plan to go 7-10 at my current 1k miles per year rate of use).

 

I think replacing them is the right thing to do.

 

very interesting info, thanks for posting. Also very interesting to see the "odd number" months. It could indicate some people only replacing one tensioner which I would find odd.

Anyway, I'm in the "swap them out" camp, at least every second (or at a push, third) major since I have personally had one fail & posted here about it a few years back.

 

Since you are never going to sell that car just change it and make it perfect. When your labor costs are essentially free you can spend more on the best parts.

 

"odd" number months probably indicates more 360 customers instead of F355. Remember, there are two different part numbers being used on the the 360: 157356 and 202784

 

I don't want to tell you how many years I have gone.

 

Daniel, is there still an fchat discount?

 

Hah. Don't listen to what he said. See what he does.

 

Not to add to the "while I'm in there" but what about the timing belt drive pulley bearings?

 

They should be done every major unless using the Hill bearings.

 

To be clear, he is talking the lower drive pulleys, not tensioner bearing. Do you really mean drive pulley bearing? I've only heard of replacing the OEM ones on 348 because the original type was pron to failure.

 

Ah, never heard of those being an issue on 355s.

 

Don't change those.

 

Ok. Thanks. Replacing the tension pulley bearings with Hill. The others I will leave (subject to opening up the car and seeing the condition).

 

If you're pulling the front timing cover and/or planning to change the chain tensioners, then (to me) it does make sense to replace those lower drive bearings with the Hill Engineering 170787. The original ones from Ferrari were ok, but the 'newer' ones since about 2010 are (trying to be polite) "substandard".

170787 https://www.ricambiamerica.com/170787-bearing.html

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Anyone know the failure rates for 355 tensioners, tensioner bearing, and drive bearing? I'm sure cases can be sighted, but given 10k cars made I wonder how many have suffered such failures. On my 95 with 33k miles the tensioner bearing have been routinely replaced but tensioners and drive bearing are original.