Hello Folks Just finishing up a major service on my 79 308 GTB that included new belts and Hill tensioner bearings. All went on fine with no fuss or drama. I have the car running and am in the process of tuning the carbs. Probably have spent 3 or 4 hours running the car on stands purging coolant, tuning carbs, checking for leaks, etc. Car is running nicely and in not overheating or making strange noises. After a bit of a synch session tonight, I was giving the car a once over when I noticed a narrow ring of white grease along the inner outside edge of the Hill tensioner on the 1-4 bank. Is this normal? Grease is not being flung wildly by any means, but I've not seen a bearing do this before, although I've not really dealt with the unusal construction of these tensioners. Is the bearing defective? I can't see the bearing on the 5-8 side as it is behind the A/C compressor so I don't know if it's one or both at this time. The bearing appears to be running smoothly and is making no noise....for now... Hss anyone seen this behavior? It would be a major bummer if I had to swap them out at this point. Thanks for any insight.
Had it happen the first time I did a belt change on my 77 GTB with Ferrari bearings, so I’d say normal.
Seals on a sealed bearing are not absolute. They do a pretty good but not perfect job of keeping grease in. They do a good job of keeping debris out. They are not good at keeping pressurized water or detergents out so no washing of the motor until you are in the process of replacing bearings.
I had three kinds of tensioner bearings during the past 24 years. Genuine Ferrari, when they were $250.00/pair back then. SKF substitutes, when those were still of good quality. And now the Hill bearings. All lost a small amount of grease. Best from Germany Martin
Thanks for the reassurance. My first time doing this particular procedure on the car and I was concerned that something was amiss with the parts. Very much appreciate the replies....
As noted, normal. A couple yrs ago we had a brand new set of SKF bearings fail on the dyno, they lasted all of 20mins.. seals popped lose and grease went flying. Thankfully on the dyno and no damage. SKF used to run test them, not anymore. I run test them now before install.
Common wisdom says its pretty cheap preventative procedure to change the bearings every time the belts are changed. Your SKF story makes me wonder how long good bearings can last. Changing the bearings puts the car in jeopardy until the bearings prove themselves. My personal decision is to not change bearings this upcoming belt change; my Hill bearings only had 9,000 miles and 5 years on them. It seems like the Hill bearings, like all the other bearings in the car, should last a lot more than this. Is this flawed logic? What is the estimated service life of a good tensioner bearing like the Hill Engineering ones?
I personally have no plans to replace my 3rd old Hill Bearings, 3 years from now. Perhaps that will change, but at present - no.
No. The design of the tensioner bearings is heavily overdimensioned. I once did a lifetime calculation based on SKF tech specs for such angle roller bearings and this led to astronomic results. Noone would keep his bearings such long. The question is the lifetime of the grease in those lifetime lubed bearings. SKF talks about 30.000 hours of operation until grease should be renewed. Though most bearings live a lot longer even without renewal of the grease. So now you can calculate how many years the bearings will last based on your 9000 mls. in five years. Question is. How many hours for the 9000 mls. I assume, that most tensioner bearing failures -on all cars- are caused by some maltreatment during installation or repeated steam cleaning of the engine or such things. I think of the rear wheel bearings, which would last forever, if they would be better sealed against water ingress. The low tech lip seal is a joke. And IIRC the very early 308s even came without any additional seal.. Best from Germany Martin
