I've got 26K miles on my 2008 Nightrain and just replaced the inner primary bearing.

Suspecting that my final drive belt might be too tight causing premature failure of this bearing, I have abandoned the tension gauge and went with "feel", slacked it off just a little to be on the safe side.

I understand that an over tight primary chain could also destroy the bearing, but the tensioner is working fine and the chain was not over tight.

Is there anything else that could cause this bearing failure, ....... possibly cheap junk Chinese bearings, like my wheel bearings that failed at 9K miles?

 

 

Yes I did.

This is what I used.

 

As far as bearing failure is concerned, I went back to my (very) old book from Shell Oil.
Bearing failure rates~

1. Dirt........................….46.92%
2. Misalignment...……...14.29%
3. Misassembly..............11.29%
4. Overload......................9.58%
5. Insufficient lubrication..8.50%
6. Corrosion.....................5.17%
7. Indeterminate/other......3.75%

Low lubricant level caused by neglect
Improper grade of lubricant
Excessive temperature
Overloading/overspeeding of bearing
Normal "wear"

These are just some of the things that can eat bearings.

 

My 01 I replaced at 34k, cause I had primary off. Did not replace chase. 78k still good. My 07 whined at 27k, and not again at 57. At 27 I replaced tensioner with spring version. So that or that bearing was the issue.

My theory was the tensioner is to tight and is cause all the problems they have been chasing since 6 speeds. They re-invented the wheel with the tensioner. Looks like horse sh^t design to me too.

2nd theory is cheaper bearings. They are building these for people who don't ride. Most don't see 30k, or a 2nd 30.

Trying to decide right now what to do, just parked it last night. Which brand to go with?

 

I just had to replace my I.P.B. @ 35,000 miles on my 08 ultra. Mine had a very small chunk off one of the needle bearings and that destroyed the race. Personally I think its a combination of poor quality bearings and the auto tensioner. My tensioner was tight but not guitar string tight. It all happened very fast, every winter I would check the tension of the chain and it was always good. Last winter I noticed it was tighter then normal, but not overly tight I reset the tension and put it back together with new oil(every winter).Along about mid June I started to hear the tall tale growling sound with clutch engaged. So in mid July with a 2000 mile trip coming up in a early august, I tore it apart and replaced every thing including a new baker attitude adjuster chain tensioner. Alls working good now and my next investment will be to replace the all inferior compensator. I love Harleys and always will it just gets frustrating to continually have to replace inferior parts on these machines. As far as what brand to use for tensioner and or comp, baker is the only way to go. Expensive investment but the last one you will have to do.

 

This pretty much sums it up right here ! Along with the overly tight primary chain.

 

If that book was current, made in china would be number one on that list.

 

Had to replace my IPB at about 35K, replaced the stock chain tensioner with a Hayden unit and replaced the IPB with the Baker unit..........at 50K no problems!!

 

Mexican actualy