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[SE08RK]

Timkens hold the crank in position with tapered rollers where the straight roller bearings let the crank bounce back and forth against shims. It was a sad day for the engine and customer when Harley decided to go back to the pre 1956 bearing system. It is just plain cheap! These sorts of reversals in technology and efficiency are what is going to destroy Harley Davidson Motor Company. Their interest in the bottom line is the driving force and they are destroying an American icon in their quest to make money. Strange that HD MoCo cannot learn from foreign motorcycle companies that in their attempt to copy Harley's engine, they actually wind up building a better product. But we just keep buying HD's product, feeding their greed.

The increased size in the drive side bearing is a good example of the knee jerk reactions that Harley Davidson has toward rectifying a poor decision in the recent past. They need to 'go back' to the pre-preloaded Timken tapered roller bearing assembly for all of the TC engines.

BC

[grc]

bisounours & SE08RK

I believe the 96 " bikes now have the heavier bearings in them. When I started looking into my motor build for this winter, the service manager at an area HD stated the 08 CVO's had timken bearings in the left side. I thought the information was incorrect and used the Ask Mike at Latus HD. His answer is below:

I cannot confirm the Timkens in the 08 CVO 110's. The H-D technical forum does not mention this change. The forum does state that the CVO 110's are carried over from 07 with out mention of motor changes. The drive side bearing was updated to a heavier design first used in the 110's but now used in all models and as a replacement in all 03L motors when this bearing is changed. It is also included in the new SE 110/113 kits, when used on earlier models. This bearing is still an INA single row roller bearing P/N 24605-07 (bearing only), 24004-03A (bearing kit-includes retaining rings).

We have also, not heard of any restrictions on the Race Tuners.

Mike

Based on his answer, it appears these heavier bearing are now in the 96 / 110 motors. Maybe the MoCo thinks they have a problem in the bottom end but don't wish to tell anyone?   I know I don't know chit so I ask those that are supposed too.

FWIW: The guys at the Harley shop I use told me straight out the Timkens had been dropped in 03. They disagree with Mike and recommend installing Timkens if you upgrade or plan to keep your scooter for a long period.

JW

What I glean from the '08 SE catalog is that the larger drive side bearing only comes with the Stage 2 110 kit, not the Stage 1 kit that is equivalent to the CVO engines.

In theory, a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings.  Dig around inside a typical automotive engine and trans, and you won't find many dual row opposed Timkens.  You'll find plenty of plain or roller bearings with thrust washers to control endplay.  IMHO, where Harley went wrong is in assuming they could use the same bearing on the more heavily loaded drive side of the crank that they use on the lightly loaded cam drive side.  Makes one wonder if they let the same guy who picked the original cam bearings for the Twin Cam try his luck again when coming up with this little "cost reduction".  

One thing everyone is going to have to understand is that the "bean counters" are firmly in control at the MoCo.  I have to believe that at least some of the engineering staff understands that many of the changes made in the past few years are major steps backward in terms of reliability, but they also know that if they want to keep their jobs they will do as instructed.  Having gone through much the same thing in the auto industry in the past decade, I can understand (but still not like) the fact that when faced with tough competition and high costs you have to do whatever it takes to survive.  However, I don't see the same situation with H-D that I see with Ford/G-M/Chrysler.  Harley doesn't have foreign competitors taking huge chunks of their market share, nor do they have the pricing pressures of the auto companies.  Harley has the highest prices in the industry, and has been able to increase prices with impunity.  So the question is, why do they feel the need to cheapen the most important parts of the motorcycle?  Can we all spell  g r e e d ?

Jerry

[sadunbar]

What I glean from the '08 SE catalog is that the larger drive side bearing only comes with the Stage 2 110 kit, not the Stage 1 kit that is equivalent to the CVO engines.

In theory, a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings.  Dig around inside a typical automotive engine and trans, and you won't find many dual row opposed Timkens.  You'll find plenty of plain or roller bearings with thrust washers to control endplay.  IMHO, where Harley went wrong is in assuming they could use the same bearing on the more heavily loaded drive side of the crank that they use on the lightly loaded cam drive side.  Makes one wonder if they let the same guy who picked the original cam bearings for the Twin Cam try his luck again when coming up with this little "cost reduction".  

One thing everyone is going to have to understand is that the "bean counters" are firmly in control at the MoCo.  I have to believe that at least some of the engineering staff understands that many of the changes made in the past few years are major steps backward in terms of reliability, but they also know that if they want to keep their jobs they will do as instructed.  Having gone through much the same thing in the auto industry in the past decade, I can understand (but still not like) the fact that when faced with tough competition and high costs you have to do whatever it takes to survive.  However, I don't see the same situation with H-D that I see with Ford/G-M/Chrysler.  Harley doesn't have foreign competitors taking huge chunks of their market share, nor do they have the pricing pressures of the auto companies.  Harley has the highest prices in the industry, and has been able to increase prices with impunity.  So the question is, why do they feel the need to cheapen the most important parts of the motorcycle?  Can we all spell  g r e e d ?

Jerry

That's the part that makes me crazy...  Keep your fly by wire throttle.  Keep your automatic tour pak and saddle bag locks - but give me proper bearings, give me a motor that doesn't leak oil.  Put the money into the quality of the important stuff and screw the gadgets...

  whew...that's better

Scott

[SE08RK]

What I glean from the '08 SE catalog is that the larger drive side bearing only comes with the Stage 2 110 kit, not the Stage 1 kit that is equivalent to the CVO engines.

In theory, a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings.  Dig around inside a typical automotive engine and trans, and you won't find many dual row opposed Timkens.  You'll find plenty of plain or roller bearings with thrust washers to control endplay.  IMHO, where Harley went wrong is in assuming they could use the same bearing on the more heavily loaded drive side of the crank that they use on the lightly loaded cam drive side.  Makes one wonder if they let the same guy who picked the original cam bearings for the Twin Cam try his luck again when coming up with this little "cost reduction". 

One thing everyone is going to have to understand is that the "bean counters" are firmly in control at the MoCo.  I have to believe that at least some of the engineering staff understands that many of the changes made in the past few years are major steps backward in terms of reliability, but they also know that if they want to keep their jobs they will do as instructed.  Having gone through much the same thing in the auto industry in the past decade, I can understand (but still not like) the fact that when faced with tough competition and high costs you have to do whatever it takes to survive.  However, I don't see the same situation with H-D that I see with Ford/G-M/Chrysler.  Harley doesn't have foreign competitors taking huge chunks of their market share, nor do they have the pricing pressures of the auto companies.  Harley has the highest prices in the industry, and has been able to increase prices with impunity.  So the question is, why do they feel the need to cheapen the most important parts of the motorcycle?  Can we all spell  g r e e d ?

Jerry

You'd be hard pressed to even find a roller bearing in an auto engine or transmission. Comparing my Harley engine to an auto engine is an insult anyway    Sort-of hard to compare a set of preloaded tapered roller bearings to a straight roller too. Different application for different purposes - except with Harley's engineers. They apparently don't understand the difference either. The crank in a Harley heeds the stability of the Timken bearings and that was the thought when the V twin began to get larger and more powerful. Now all of a sudden the Twin Cam doesn't need them? The Pan Head was where HD went away from shims to keep the crank stationary but like the new system, a limited selection of shims are available so the crankshaft is replaced if too much lateral play exists. So, who benefits from this 'just as good' bearing? The Timken set lasted the entire life and then some, of the engine and I doubt seriously that a rebuilder of the current TC will reuse these cartridge, cheap, inadequate bearings. Auto engines use friction bearings with full circle friction thrust bearings too, normally babbit lined inserts. Think HD could do this?

BC

[Deacon]

When I had my 110 kit installed I told the dealer I had read that there was a stronger crank bearing that should be installed. I read this at the time on the knight rider site. The dealer called MOCO and they said the bearing should be installed. I found the PN# on my invoice. For what it's worth here is the upgraded PN#. 24605-07. Hope this helps. This was back in MAY 07. The price was $30.90

[grc]

You'd be hard pressed to even find a roller bearing in an auto engine or transmission. Comparing my Harley engine to an auto engine is an insult anyway     Sort-of hard to compare a set of preloaded tapered roller bearings to a straight roller too. Different application for different purposes - except with Harley's engineers. They apparently don't understand the difference either. The crank in a Harley heeds the stability of the Timken bearings and that was the thought when the V twin began to get larger and more powerful. Now all of a sudden the Twin Cam doesn't need them? The Pan Head was where HD went away from shims to keep the crank stationary but like the new system, a limited selection of shims are available so the crankshaft is replaced if too much lateral play exists. So, who benefits from this 'just as good' bearing? The Timken set lasted the entire life and then some, of the engine and I doubt seriously that a rebuilder of the current TC will reuse these cartridge, cheap, inadequate bearings. Auto engines use friction bearings with full circle friction thrust bearings too, normally babbit lined inserts. Think HD could do this?

BC

BC,

So, what you're telling me is that you don't want a reliable engine that will last at least 100,000 miles in your Harley?  Well, you're in luck, since I seriously doubt you'll find many of Harley's latest offerings still running strong at 100,000 miles.  What you will notice with many of the changes H-D has made in the recent past is that they really don't care about providing anything  more than "just barely good enough".  They don't want people to be able to easily rebuild their engines, they want to sell new ones.  This is a design philosophy that folks like Toyota have made a cornerstone of their business; eliminate the over-engineered parts and make everything just good enough.  Why buy rocker arms that will last 250,000 miles, for instance, if the rest of the engine only lasts 100,000 miles?

I stand by my original statement; in theory, a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings.  Would I rather have the Timkens?  Sure, if for nothing other than piece of mind.  And it would also be helpful if the crankshaft was true and strong enough to stay that way.  But I don't believe a stock output engine needs Timkens to survive, and that is obviously the approach Harley is taking.  If you want to hot rod your engine, they obviously no longer plan to provide a bottom end that you can leave stock.  Now you'll have to spend more to split the cases and upgrade the crank and bearings.  Assuming the stock setup is adequate for a stock output level, making it more expensive for someone to seriously increase power isn't something the manufacturer is going to lose any sleep over.  

Jerry

[SE08RK]

BC,

So, what you're telling me is that you don't want a reliable engine that will last at least 100,000 miles in your Harley?   Well, you're in luck, since I seriously doubt you'll find many of Harley's latest offerings still running strong at 100,000 miles.  What you will notice with many of the changes H-D has made in the recent past is that they really don't care about providing anything  more than "just barely good enough".  They don't want people to be able to easily rebuild their engines, they want to sell new ones.  This is a design philosophy that folks like Toyota have made a cornerstone of their business; eliminate the over-engineered parts and make everything just good enough.  Why buy rocker arms that will last 250,000 miles, for instance, if the rest of the engine only lasts 100,000 miles?

I stand by my original statement; in theory, a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings.  Would I rather have the Timkens?  Sure, if for nothing other than piece of mind.  And it would also be helpful if the crankshaft was true and strong enough to stay that way.  But I don't believe a stock output engine needs Timkens to survive, and that is obviously the approach Harley is taking.  If you want to hot rod your engine, they obviously no longer plan to provide a bottom end that you can leave stock.  Now you'll have to spend more to split the cases and upgrade the crank and bearings.  Assuming the stock setup is adequate for a stock output level, making it more expensive for someone to seriously increase power isn't something the manufacturer is going to lose any sleep over. 

Jerry

How many auto engines have you ever seen with built up crank assemblies, or split cases, or individual cylinder - head assemblies? The comparison stops with gasoline as the fuel. Your decision is fine to go with the cheaper straight rollers even in your stock motor. I'll go with the far superior Timken Tapered Roller bearings that are preloaded for a true precision true running crankshaft. Thanks anyhow.

BC

[SE08RK]

From the perspective of a machine tool builder - if your primary goal is precision - preloaded angular contact ball bearings are the most precise solution, followed by preloaded straight roller bearings, followed by Timken tapered roller bearings.  Timken tapered roller bearings are most adversely affected by heat growth, as the preload increases/decreases with heat expansion to a greater extent then preloaded angular contact ball bearings or preloaded straight roller bearings.  Now, if the primary goal is strickly being robust and able to withstand extreme forces (such as tooling breakage or "machine crashes"), then the Timken tapered roller bearings win hands down - by a large margin.  I agree with Jerry that there is no technical reason that properly lubricated and sized straight roller bearings with thrust washers are not perfectly adequate for the application in Twin Cam motors.  I agree with SE08RK that Timken bearings are by far the more robust solution - but they are not the more precise solution.  I believe the larger problem resides with the Crank/Flywheel assembly - not with the bearings supporting them...

later...Scott

 Hey Scott,

  How do you preload a straight roller bearing?

Thanks for the education,
BC

[SE08RK]

Sorry, I apologize to you for my choice of words.  I was not attempting to "educate" anyone.  I was only commenting on the differences between various bearing options - agreeing with Jerry that a properly sized and lubricated roller bearing with thrust washers should work fine in place of the higher cost Timken tapered bearings - and agreeing with you that Timken tapered bearings are a more robust solution - BUT there are compromises with both solutions.  In the future I will be more careful with the accuracy of all my words when commenting to your posts...

The point I was trying to make was IMO the bearings are not the weak link in the bottom end of these motors - regardless of which type bearings are used.

later...Scott

Well, that's great! You were talking about the cases in a bearing discussion. You said you are a "machine tool builder" with some information. Now you are saying that " when commenting to your posts... ".  Well then; I feel deprived....

I still want to know how a straight roller bearing is preloaded. You are not just relating this information to me, you are going to tell the world: "How to preload a straight roller bearing".

Go for it! Explain....

BC

[110tHunDer]

 
BC, let's keep it civil in here.  I think you can make your point without the abrasive tone.

[SE08RK]

BC, let's keep it civil in here.  I think you can make your point without the abrasive tone.

Where's the uncivil, abrasive tone?    I wish for Scott to explain how to preload a straight roller bearing, and since he's an expert machine tool builder  , he can relate much super informative information to us. Please allow Scott to explain this....

 Are you interceding in a discussion?  And why?    What did I do?     Ask a question?
 
This guy is withholding valuable information.....

BC

[110tHunDer]

Where's the uncivil, abrasive tone?    I wish for Scott to explain how to preload a straight roller bearing, and since he's an expert machine tool builder  , he can relate much super informative information to us. Please allow Scott to explain this....

 Are you interceding in a discussion?  And why?    What did I do?     Ask a question?
 
This guy is withholding valuable information.....

BC

Abrasive tone, excessive sarcasm . . . . call it what you want, but I think you know what I'm eluding to.  And yes, since you asked, I was stepping in on this conversation.  And this is twice now.  Move on.

[Twolanerider]

And why?   

He's a moderator.  He doesn't need a "why?" 




(Out of courtesy he gave you one though.)

[SE08RK]

So yall lookin to git rid of some folks?

[Fired00d]

So yall lookin to git rid of some folks?

Nope, but respect gets respect.

 
Ride Safe,
Fired00d