Actually I'm not in any pissing match here with anybody. And if people read just a bit more carefully they would see my REAL STANCE on the new 6 speed from the Dyna models. Though I find it pretty naive for people to replicate claims that HD's marketing dept. is responsible for.

Lets go over my STANCE one more time:

A. The jury(which in this case means MYSELF) does not have an opinion one way or the other on the new 6 speed Dynas from a reliability or durability standpoint. But I am not going to blindly go along with HD's claim that these transmissions are stronger in a beneficial way to the end user. The claimed stronger transmission case and larger shaft bearings that come with the transmission are due directly to the fact that helical gears put alot of thrust directly into the side of the case and the bearing race, and the more torque you engine puts down, the higher the thrust load. So HD had to reinforce these areas. The question is, did they reinforce it enough for engines that are highly modified to put significant more torque down than a stock engine. Overall it still does not mean that the transmission is structurally superior since transmissions with straight cut gears do not have lateral thrust issues. In other words, helical gear transmissions have more issues and wear points to be concerned about because of the lateral thrust they put out. Time and miliage will tell just how good these transmissions are.

And JamieHG: laying down a measly 3000 miles on a stock motor to me is not an indication that the transmission is up to the abuse that the older models have already proven to be. Come back when we have bikes with 50-100k or more of miliage without issue and warrenty claims have shown to have a low percentage number overall. Feel free to post on a metric site. They will probably be just as knowlegeable on past HD designs as they are on your current design. Another useless adventure it sounds like to me.

B. The 6 speed transmission on those dyna models are a bit quieter due to the helical gears. I agree. I also feel that a transmission that has a bit lower operating db is a non factor when you run with anything other

 

He's ignoring several things. If the helical cut gear is larger than the straight cut gear, it will also be stronger. Size of the gears comes into play and ruins this simplistic explanation. Also, in a helical design, more gear teeth are engaged at one time vs straight cut gears. In a straight cut gear, only one tooth is carrying the load. Given equal strength materials (steel), the helical gears will be stronger. That's why, as mentioned above, the Navy can use helical cut gears on a battleship. That's why helical cut gears can withstand the force of F1 racing. The new transmission design also results in much smoother shifting. Just about every single manufacturer of vehicles has switched to helical cut gears, including high end, cost is no barrier, manufacturers like Porsche, BMW and Ferrari. And that's why the new 6-speed is the strongest transmission HD has ever built.

 

This thread is hilarious! All of you guys have helped me with prior posts. Just blame me for everything and lets go ride tonight. Kinda a polar bear ride, any takers?

 

Hey no problem. Just one thing though.... I bought into the HD propaganda and my crappy new 6-speed may self destruct at any moment. Think I can ride b*tch if my bike explodes?

 

Jamie: You need to take your daily Prozac pill. Lets get real here. I have a HD because I love the bike. And overall the bike is a well designed unit. But people who work in this industry know that HD tends to make cost saving mfg. cuts as a product develops over the years. They have done this in many cases.

Lets take a look at the TC platform in general. In 99' when it came out the TC engine was well built. It came with Timken crank bearings, an oil pump that had a very high output and was a great first year product. One big glaring issue was the rear outer cam bearing. It was a basic ball bearing type and it tended to fail prematurely. HD fixed this and went to a rear outer roller cam bearing. The problem for the most part was solved.
Over the next few years(00'-02') there were pretty much no significant changes. Though HD did a revision on the oil pump. The new model actually put out less oil pressure and volume.
Then in 03' HD replaced the Timken crank bearing with a straight roller bearing. This new bearing has shown to be unreliable in higher hp motors, and wholesale price difference between the new style roller bearing and the old Timken bearing was in the $10-15 dollar range. Take that number and times it by 600,000. Thats what HD saved by switching bearings. An obvious cost cutting more with no upside for the end user.
In 05' HD went to a much cheaper beehive spring pack assembly in their cylinder heads. They have known to have issues with the seals and there are numerous cases of oil burning and excessive consumption. Again about a $5-10 over the traditional spring pack assembly. Take than number and times it by about 400,000 to date. HD currently has now updated the valve seal to resolve the issue. Best thing to do is use an aftermarket springpack assembly if you plan on doing some performance modifications to the engine anyway.
Recently on the TC **A motor they changed out the outer cam bearings for basic brass bushings. Thats a big savings right there. Probably close to the cost of the old style cam bearings themselves. Times that by however many units they make presently till the end of the TC production run in who knows how many years from now.

HD did make a few upgrades that I will note. On the TC88A, internal oil lines between the engine and transmission have been incorperated. They probably saved money on this, but its still a good move to clean up the engine's look by having less external oil lines running outside the case. HD also changed to hydraulic tensioners from the spring loaded design. Is this an upgrade? Not sure yet. They must think so, since the chain tensioners have always been a weak point due to good ol' EPA noise issues. Best thing to do is toss the chains and go gear drive anyway. The oil pump was also mildy redesigned to improve scavaging. Bout time they did this, probably no cost in the difference either.

This in general gives you an idea of how HD "thinks" as the production run of a design ages over

 

Why do you feel the need to post these huge lectures for me? I understand your opinion. We disagree. Is that such a huge ordeal in your life? How come you spend all day posting on the net if you're this hot shot mechanic? I'm beginning to have doubts about your employment. It surprises me that a cheap outfit like HD doesn't have you busy doing something else besides arguing with a lowly magazine lemming such as myself. Seems like you're always here, day in and day out. ... You'll have to excuse me for a few minutes now, I'm gonna go see if my transmission exploded yet.

 

First off, HD's new "helical cut" gears arent of the same quality as their older straight cut gears. Did you know that? Do some research and tell us your findings of the difference. Second, I already mentioned the fact that helical gears have more teeth in contact at all times, thats not in question, but directional applied force is a big issue, one you probably dont understand and continue to avoid. And thrust load is another big issue and a big downside to helical gears.

And lets hit on the car mfg. issue with helical gears. All car mfg. use helical gears due to noise. Ever put your car in reverse and hear the whine? Thats a straight cut gear. When your in a BMW or Mercedes the last thing you want to hear while driving is a whine. Different application when your on a motorcycle on the open road. So lets drop the rediculous comparison here between a car and a motorcycle.

And do yourself a big favor and do some research on those Indy cars. Many still use straight cut gears. It all depends on the mfg. and philosophy used in the power delivery. But many use straight cut gears becuase the power delivery is MUCH MORE EFFICIENT and noise isnt a concern. Hell have you ever been to an Indy race? You think their main concern is noise?

 

They aren't the same quality? That's what you say. HD says different. Don't tell me to do research... when you are the one making the statement, you're the one who's got to prove it. For the sake of argument, let's say the material is a lesser quality, the design of the gear can overcome that. More teeth engaged equals more strength. Gear size, materials and angle of helical cut all factor into the strength issue. You're smarter than a HD engineer? You really think they want to warranty a bunch of low quality trannies and put their reputation on the line? Sorry dude, I don't buy it. I believe the new transmission is stronger. You don't. Keep telling yourself that SE 6-speed is the ****... perhaps it is. As for the thrust factor, yeah, there are loads. So what? You have zero proof, other than your opinion (read - best guess), that HD's engineers haven't factored in the thrust loads. First you said it was all HD propaganda and in your last posts, you are admitting they beefed up the tranny housing. Guess what? Thrust loads. I'd say they had the foresight to deal with the issue.

Most auto manufacurers actually switched to helical cut gears a long time ago. You want me to drop the auto/bike comparisons because it destroys your argument. The comparison is valid when you keep bringing up strength. Know of any streetable HD's that produce 400 HP? I didn't think so. Helical cut gears have withstood large HP uses, over long periods of time, for decades. Noise isn't an issue in racing applications, so if helical cut gears are cheap garbage, then why would they use them in competition applications?

Do yourself a favor and research Indy cars, passenger cars, BMW cars, BMW bikes, Naval ships, and just about every other application that involves a transmission. Helical cut gears are modern technology. Actually, they've been modern technology for several decades. You're slagging the new 6-Speed because you own something different. Your previous post about the advantages of the SE 6-speed are proof. If you like the straight cut gears of the SE, then great. I'm glad you're happy. I happen to be happy with the new 6-speed HD has put out. Why is this a problem for you?

 

We've wandered a long way from the original thrust of this post. No biggie there, 'cause that's the nature of a forum.

We've also gotten a little "pissy" with each other, too. I'm figuring anyone who reads this series will be able to separate the wheat from the chaff, so I've let it ride because there has been some very good technical info posted. But we're now apparently at that point where the rehashing is doing nothing but raise temperatures.

With that in mind, I'm making the decision to lock the thread. It is solely my decision.