Tensioner Bearing condition opinion

700 miles? Damn. Looks like the seals are done and there is spalling. The top one just looks like lube (as if bad seals wasn't bad enough) but the bottom photo looks like more than just lube. Seal particles, lube, and possibly actual metal spalling. Factory parts? That is sad!!

 

Spalling? Evidence?

 

I have never seen one not loose some grease. Ever. The seals are not absolute and their primary function is to defend against ingress of foreign material.

The debris in the grease is debris, not bearing material. The inside of the belt covers is a pretty dirty place and dirt sticks to the grease.

Great and common scare tactics though. Works nearly every time.

 

Off center? How do you think the belt is tensioned?

Doesn't matter how the HE bearings will look. Slight grease loss past the seals is normal on many bearings and not a sign of imminent failure. It does obviously make a great sales tool though.

 

Well, failure analysis from internet photos is a seriously problematic exercise.....but...

In the lower picture, I think I see re-solidified balls of metal (look kind of shiny). The pattern of these at ~10 o'clock and 4 o'clock seem to be slung out from the bearing seals. As Wikipedia puts it Spall are flakes of a material that are broken off a larger solid body and can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball bearing). Spalling in a bearing is often seen as these small balls of molten metal from the excessive drag, friction, and subsequent heating. And it takes some serious heating. If those balls are from the internals of the bearing, either races or balls, then that was incredible localized heating. But not unprecedented. They seem to originate from the inner race but I'm really pushing based on just one photo.

 

If he will send us the old bearings I'll bet $1000 you are wrong.

How about it?

 

Nope. Not based on internet photos. Not a chance. Plus, I'm wrong about 60% of the time. Bad odds all the way around.

You think that stuff is grease and just average filth?

 

Based on the last several hundred I have inspected....yes.

 

You are, no doubt, correct. That is a lot of grease and crap for 700 miles. Do you know who the OEM on those bearings might be? In my design work, it is usually appropriate to spec ABEC-7 or 7P and I tend toward NHBB. I've never had one of their's look like this with such little running life.

 

NHBB makes a lot of crap too. They make the short lived ball joints on 360/430.

I have no idea who made them nor have I ever cared. In any event the bearing manufacturer and the component manufacturer are probably different companies.

 

No doubt, again. NHBB ABEC 3 and 5 are "price point" products with nothing but long term reliability headaches waiting for the unwary manufacturer who designs around them. 7 and 7P instrumentation grade stuff is made in a different factory and subjected to entirely different specs and testing requirements. They remain certified for flight instruments. Folks who go cheap on bearings get exactly what they pay for. And downstream product maintenance costs as an added penalty!!

 

Ferrari has been sourcing bearings from low bidder Asian companies who do not put a brand or logo on them.

It is a big part of why Hill Engineering has built a good business.

This is one of a few areas where in modern times Ferrari has been really stupid.

For their entire history their parts have been expensive and in some cases less than top quality. They got away with that for a long time but greed drove the prices so high, and more recently the quality so low that for even a small manufacturer like Ferrari it finally got so bad it became financially reasonable for competitors like Hill to enter the market place. If they had been a little less greedy they could still have a near monopoly.

Now they are making efforts to monopolize the service of the cars. What a laugh. Just like with their approach to parts, every step taken antagonizes and alienates more of their customer base.

 

What is the warranty on those bearings from Ferrari? Assuming they were even installed by Ferrari?

 

Less than 5 years, for sure.