308 Tensioner Bearing going out after less than 2 years?

Each new part hides the risk, that it may be faulty. Although industrial manufacturing is at highest standards these days, there's no insurance.
Three years ago I purchased a brandnew set of cam followers for a 4-cyl Alfa. They were all NOT HARDENED and failed after 1000 kms. The OEManufacturer just forgot hardening.
I don't want to start a new thread about cambelts here. BEWARE ! But for the belts the time is an issue. For the tensioner bearings you can count the miles. So excessive replacement is not recommended for the tensioner bearings, because chances are growing, that you catch one, which is faulty.
Or would someone state, that a 7 years old bearing with 5000 kms is bad ?
Like mentioned above; I don't intend to start a new belt thread, but if someone has arguments, that a tensioner bearing with low miles goes bad over a certain time, I would be highly interested in.

Best Regards from Germany

Martin

 

I had a brand new one fall apart in my hand at the parts counter at Ferrari of Atlanta. Kind of made me worry about the one they replaced it with, but two years later they are holding up well.

 

My personal feeling is that the bearings are the weakest part of the timing belt assembly. If they get noisy or arouse your suspicion, replace them and the belts no matter how much time or miles is on them..

 

The 308 tensioners are very fragile until they are installed. Without the bolt to hold the two inner races together, the only thing holding the whole thing together is the seal that keeps the grease in. It's hard to explain without showing a diagram. In any case, I destroyed one assembling it by pushing on the wrong place (the outer race). Once installed, they are considerably more robust. It doesn't surprise me at all that one would fall apart in your hands at the dealer. Better there than home in the garage after which they will not replace it for free!!

As for prematurely wearing out, I can suggest two things. It was either faulty from the start with not enough lube, or a leaking seal or perhaps unhardened balls. (heh heh heh...he said unhardened balls!). The other possibility is that the belt was over tensioned. I would think that would break the belt before the bearing, but who knows. Those belts are pretty tough.

I personally am of the opinion that when you replace belts you should replace the bearings at the same time. The chances of a new one being ready to die are less than an old one being ready to die, even if if has been fine for a while. Just my $.02.

Birdman

 

I agree with Birdman, change it all while you're in there.
I've installed a lot of bearings on other things and I have never had one fall apart like the tensioner bearing did, I mean it fell to pieces, ball rolling around on the floor! I know he said........

 

I replaced both tensioner bearings on my 308 last year. After only a few (less that 20) miles I had to remove the belt covers again because of an unrelated problem and found one of the bearings to be throwing some grease past the seal, but the other was fine- just a little grease.

I pulled the bearings and both seemed to operate fine with no looseness or noises. Being cautious, I called T. Rutlands (where I buy most of my parts- including these tensioner bearings) to explain the situation and they had never heard of this problem. Obviously, most 308 tensioner bearings don't get an inspection after 20 miles, but Rutlands sent me a new one free of charge. Great folks.

I could see how a sealed bearing could fail with low miles if the seal leaks out the internal grease. Does this make sense? I am certainly not a professional, so I could be totally wrong. Happens all the time.


Put everything back together with new belts again, and all is well for close to 2000 miles.

Basically-bearings are not created equal.

 

My OEM bearings spit a little grease too I got them fro FOA and I was told that that was normal that they would loose alittle.

I actually have a different problem my rear belt moves about 1/4 of an inch to the outside of the bearing every time it gets warmed up then when cold it moves to the inside of the bearing. I replaced my entire timing gear assembly and bearings on that side twice aand it still does it. FWIW the front belt rides exactly in the middle and the original one did also. I am thinking it might be the tensioner bearing assembly, but not sure. I talked to at least 4 F-mechnics and got various responses... why are you staring at the belts, later ones have covers and I never even see the belts after installation... if it was a bad timing bearing the belts would move to the inside.... and why are you staring at the belts anyway??????

 

1 in 100 SKF fail? That just seems totally unacceptable in the 21st century. But the truth otherwise is, that new parts are never as trustable as a good used part. Think of going up in a small airplane. What would you have more trust in, the brand new engine with less than 10 hours of use, or the one with 400 hours? New parts always have a running in period where the parts moving against each other wear in a pattern, and on occasion the part never gets happy, but instead starts to deteriorate rapidly. But if it proves itself past 50 hours, or 100 hours, and is still running cool and quiet, chances are that it will continue to run like that for many hundreds or thousands of hours.

In other words, If I were building a motor and car for Lemans, I would want to build it with parts that were already run in, including belt tensioner bearings.

 

I Totally agree.

Martin

 

Which dealer did the service? I know FoA warrants the parts and labor on major services they do for 12 months.

 

I would always bring my parts when I had a mechanic; if they failed he was (rightly) not responsible. If this guy did that, he's SOL.

Ken

 

Sounds like a big no no to me. Why on earth would a dealer use non-factory parts??