Welcome to Our Community

Wanting to join the rest of our members? Feel free to sign up today.

Sign Up

Interesting bearing failure artice on 6 speeds

Discussion in 'Dyno Runs' started by Nomad2day, Jun 29, 2008.

  1. Nomad2day

    Nomad2day Longhair Redneck Geek

    Joined:
    Nov 3, 2007
    Messages:
    2,607
    Likes Received:
    33
    Trophy Points:
    38
    Location:
    Clarksville TN
    My Bike(s):
    Gone but not forgotten 07 Bulldog, Now a 1966 Harley Davidson FL Electra Glide
    First Name:
    Neil
    While searching the Internet to learn what makes the baker 6 speed, how it is made and researching bearing failures, I ran across this article. Thought I would throw it out here to hear other people thoughts on this.

    Dr. Chaos Service Bulletin #26 speed transmission bearing failure.
    There has have been numerous reports on trap door bearings and the main shaft main ball bearing going bad prematurely on six speed transmissions on all makes. I have personally seen bearing damage and main shaft bending from the Rev Tech 6 speeds. I've also heard from very reliable sources that Baker and yes even Harley has have had trouble with their six speed transmission bearings. The next sentence is not entirely accurate but will suffice for this discussion. The six speed transmission uses pretty much the same design as the proven 5 speed design only with an extra gear. The problem is, is with the main shaft and the fact that the clutch pack is mounted so far away from the shaft support which is the main shaft ball bearing. The main shaft and the clutch pack is unsupported at the end. The clutch pack hangs off the end of the shaft and is flexed back and forth by the torque of the engine. The tightness of the primary chain and the secondary drive belt also contribute to stress on the main shaft bearing, which then this transfers the force to the trap door bearings. This unsupported main shaft design was adequate with a 50 or 60 hp engine putting out low torque numbers. With the recent trend in high HP and high torque engines and ever increasing and cheap affordable cubic inch upgrades, like for the Twin Cam (95 cu in.). T the 5 -speed transmission is meeting its design limits. Remember the stock 5 speed transmission in 5th gear is a 1 to 1 ratio, which turns the rear wheel one revolution for every full revolution of the engine. Now enter the 6 speed transmission with a final drive ratio in 6th gear of .83 to .89 (overdrive). Which means the rear wheel turns only .83 to .89 (roughly) of a revolution while the engine turns one complete revolution. This means that there is a lot more torque being transmitted to the unsupported main shaft with the same clutch basket hanging off of the unsupported end of the shaft. What this does is stress out the main shaft bearings and the trap door bearings prematurely before their time causing transmission failure or at the very least an early rebuild. I have seen 6 speed transmissions from every major manufacturer needing bearing overhaul around the 20,000 to 30,000 mile range. Which is way too early! I think there is something we can do to slow down this process considerably. I think we are riding these 6 speeds all wrong (me included). I think we are accelerating far too often in 6th gear and not down shifting to 5th gear as we should. We do this because we can. We now have so much more torque with these more powerful engines that we can accelerate in 6th gear without downshifting. I believe This is the problem. If we do all our accelerating in 5th gear, then once we reach cruising speed, then and only then shift into 6th for cruising. That way no excess torque is placed on the unsupported main shaft and our aftermarket transmissions will and should last longer. Just my two cents.
     
  2. Fibersnake

    Fibersnake Banjo Playing PsychoBilly

    Joined:
    Jun 11, 2007
    Messages:
    4,383
    Likes Received:
    136
    Trophy Points:
    63
    Location:
    Eastern Panhandle of West Virginia
    My Bike(s):
    2005 BD Mastiff 2009 Buell 1125R
    Very interesting indeed and makes allot of sense. I like the note of the shifting to 5th for aceleration and just keeping it in 6th for crusing. Not sure how other use the 6th gear, but myself I tend to not put in in 6th until 75 MPH or more, like to keep my RPM up near the 3000 Range and if I do drop the hammer, normally shift it down then come on up till I hit 3500 or so.

    So far no issue with the tranny and hopefully will have none. Not sure if the info you posted is accurate or not, but will say that I ride mine more like he suggest and (knock on wood) no issues with the tranny yet. Oh I do use just the standard RevTech Tranny fluid and change it out about ever other oil change. My not be crap, but it is habbit and oil is cheap.
     
  3. Raywood

    Raywood The Pirate
    Staff Member Supporting Member Calendar Participant

    Joined:
    Apr 5, 2007
    Messages:
    17,376
    Likes Received:
    668
    Trophy Points:
    113
    Location:
    Rainbow, CA
    My Bike(s):
    2014 KMW Regulator
    First Name:
    Ray
    I would add that this may not apply to the 05 and newer bikes which use the DSSC. This primary allows for a shorter shaft than the HD style primaries that have to space the motor out to clear the fatter tires such as the one on my 03.
    I haven't had an issue with either of my BD's and they both had a lot of miles on them. And 95% of these miles have been hwy miles. I use 6th gear all the time but I'm usually running 85+ unless I'm with Knotso then it's closer to a 100!
    I've also only changed the oil in my 05 three times now after the 500 mile service and it has over 52,000 miles on it. I'm pretty easy on my bike other than running at high speeds on the fwy. Also, the only oil I've used is the Redline Heavy Shockproof!! Great stuff!!!
    Interesting article though. I remember when HD did the recall on all the 6 spds when they first come out.

    :flag:
     
    #3 Raywood, Jun 29, 2008
    Last edited: Jun 30, 2008
    Psycho and Matheny 514 like this.
  4. BigDogBro1

    BigDogBro1 Made in the USA

    Joined:
    Mar 9, 2008
    Messages:
    2,047
    Likes Received:
    214
    Trophy Points:
    63
    Location:
    Near Hell MI
    My Bike(s):
    07 Bulldog, full chrome, Pergy w/gold leaf paint, V&H BR pipes, Gator & Ostrich seats
    Raywood's 52k miles of experiance makes sense to me - Both us BigDogBros don't hammer our bikes and now I'm glad of it. I for one have always considered 6th gear as a cruise overdrive and don't lug it down. Plus, treating your dog like it's a Suzuki Haybusa is something you may end up paying for eventually. Personally I don't hammer my bike when I ride - because I like to ride it, not fix it.
     
    Psycho likes this.
  5. T Mack

    T Mack SUCKER FREE

    Joined:
    Mar 18, 2008
    Messages:
    1,638
    Likes Received:
    17
    Trophy Points:
    38
    Location:
    DetRiot, MichiGun
    My Bike(s):
    2006 Mastiff
    First Name:
    Dick
    It sure is hard not to with all the power we have.... But I'm with you, I try not to Dog my Dog too much...:D :D :D
     
  6. Vegas

    Vegas Well-Known Member

    Joined:
    Nov 7, 2007
    Messages:
    2,381
    Likes Received:
    19
    Trophy Points:
    0
    Location:
    Henderson,NV
    Sul....6th is definitely not as deep as it used to be on the dogs. My 03 Chopper had a tallker 6th and so did my buddies 06 APC with the baker. Overdrive was never meant for accelerating in any machine. What is the first thing you car does when you give it some throttle...kick down a gear. I always drop it in 5th to accelerate unless I am going 75 or 80.
     
  7. chacha

    chacha Chaff Your EHC!!
    Calendar Participant

    Joined:
    Apr 18, 2007
    Messages:
    2,642
    Likes Received:
    109
    Trophy Points:
    63
    Location:
    20151
    My Bike(s):
    2001 Nightrain, 2014 Indian Vintage, 2006 Bulldog (sold)
    First Name:
    Mister Fucking Wonderful
    Interesting article Nomad -- thanks for posting. Yep -- top gear for cruise only in any machine -- even a tractor =)
     
  8. reloaderbmg

    reloaderbmg OLD DOG

    Joined:
    Nov 5, 2007
    Messages:
    1,269
    Likes Received:
    35
    Trophy Points:
    48
    Location:
    maitland fl.
    My Bike(s):
    2007 k9,2003 road king
    First Name:
    IAN
    only dog mine now & them! and in low gears, 6th is at 60mph.
    at no time from 4th gear up im below 2,000rpm. and higher in 6gear!
     
  9. EJ

    EJ Member

    Joined:
    Apr 6, 2008
    Messages:
    571
    Likes Received:
    8
    Trophy Points:
    0
    Location:
    lancaster, sc
    My Bike(s):
    2002 bulldog
    I agree 6th gear is 65 or better I dont like to lug the motor in 6th if i slow down or accelerate I downshift to 5th. I like to give the ol girl a bit of hell every now and then just to show them harley boys i ride with what the old dogs got.:cheers:
     
  10. Raywood

    Raywood The Pirate
    Staff Member Supporting Member Calendar Participant

    Joined:
    Apr 5, 2007
    Messages:
    17,376
    Likes Received:
    668
    Trophy Points:
    113
    Location:
    Rainbow, CA
    My Bike(s):
    2014 KMW Regulator
    First Name:
    Ray
    Baker introduced the DD6 (Direct Drive 6 spd) and BDM adapted it with the introduction of the 05 models.
    Earlier models used the OD6!

    Baker still offers both tranny's.

    :flag:
     
  11. rwill20

    rwill20 Well-Known Member

    Joined:
    Oct 9, 2007
    Messages:
    1,543
    Likes Received:
    71
    Trophy Points:
    48
    Location:
    East Dublin Ga.
    My Bike(s):
    2007 EFI Bulldog
    Thanks 4 the article,makes sense.:cheers:
     
  12. V

    V Guru

    Joined:
    Nov 1, 2007
    Messages:
    5,397
    Likes Received:
    50
    Trophy Points:
    48
    Good info
    If you were to switch to a open primary it seems like you would want the outer support, right?
     
  13. awags

    awags Member

    Joined:
    Apr 22, 2008
    Messages:
    89
    Likes Received:
    1
    Trophy Points:
    6
    Location:
    Fond du Lac, Wi
    My Bike(s):
    2004 mastiff
    First Name:
    Aaron
    According to the 04 manual 65 is the absolute slowest you should use 6th. I wont even think about it till atleast 75! I never gave the tranny a second thought but lugging the engine is terrible for it- Let her scream- They like the higher rpm's anyways. I just got back from tha S&S 50th, put on about 400 miles and averaged 43-44 mpg, the best tank @ 46mpg with the girlfriend and a loaded saddle bag! I wasn't riding it hard- but do always keep up the rpm's.
     
  14. Fibersnake

    Fibersnake Banjo Playing PsychoBilly

    Joined:
    Jun 11, 2007
    Messages:
    4,383
    Likes Received:
    136
    Trophy Points:
    63
    Location:
    Eastern Panhandle of West Virginia
    My Bike(s):
    2005 BD Mastiff 2009 Buell 1125R
    awags,

    On the 05 they list 62MPH@2000RPM for 6th and 81MPH@3000RPM for 6th. I normaly do not even think about 6th unless seeing 75 plus for a good long distance. My bike does seem to like to see the 3000 RPM light on or just a tad below activation.
     
  15. dogvet

    dogvet Banned

    Joined:
    Feb 5, 2008
    Messages:
    588
    Likes Received:
    20
    Trophy Points:
    0
    Location:
    the shitty side of the rainbow
    My Bike(s):
    custom
    No overdrive on 05 and later dogs.
     
  16. emcclary

    emcclary Active Member

    Joined:
    Aug 23, 2007
    Messages:
    371
    Likes Received:
    4
    Trophy Points:
    18
    Location:
    Earth
    My Bike(s):
    2007 FLHRSE3 Road King, 2012 Custom Street Glide
    I agree with most 6th gear is strictly a 70+ mph event with downshifts as needed due to traffic etc.
     
  17. woodbutcher

    woodbutcher Mr. Old Fart member #145
    Staff Member Supporting Member

    Joined:
    Aug 16, 2007
    Messages:
    10,486
    Likes Received:
    4,015
    Trophy Points:
    113
    Location:
    hilton head is., sc
    My Bike(s):
    black cherry '07 K9
    First Name:
    Tom
    seems to me that if you have the opportunity/need to rebuild the tranny, if at all possible, change your bearings to needle instead of ball bearings to get rid of the point loading and give more of a contact area for the support of the shaft. thought may be off base, but i don't think so.

    damn, it's good to be back!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     
  18. scubaman15

    scubaman15 Well-Known Member

    Joined:
    Dec 9, 2007
    Messages:
    2,861
    Likes Received:
    60
    Trophy Points:
    48
    Location:
    New Kent Virginia
    My Bike(s):
    2007 BDM Chopper- 2007 HD CVO
    Lugging the motor is never a good idea... But I will say this if it breaks I don't want it, I ride my bike and I flog it when its safe to , Its a rush and makes me feel alive ,I also corner it till something drags ...shit I bought this bike for the performance and every Harley rider who thinks thay got a hot bike wants to try it "and some of them have true hot rods" but I love the power of the 117...when the Warranty runs out I will test the tranny with even more power ... If you can't run it through the gears what good is it!! IMHO
     
  19. Nomad2day

    Nomad2day Longhair Redneck Geek

    Joined:
    Nov 3, 2007
    Messages:
    2,607
    Likes Received:
    33
    Trophy Points:
    38
    Location:
    Clarksville TN
    My Bike(s):
    Gone but not forgotten 07 Bulldog, Now a 1966 Harley Davidson FL Electra Glide
    First Name:
    Neil
    As Raywood said, The artice may not really apply to our transmissions due to the being a dssc. This is from the Baker site explaining the DSSC some and how it is different from the other transmission. I am talking about the clutch being wat out on the mainshaft anyway.
    Good stuff.

    BAKER Drivetrain | Custom Transmission Products

    the D.S.S.C.™ drivetrain assemly (Drop Starter Slam Clutch)

    DSSC is a complete drivetrain unit consisting of a Right Side Drive transmission and an enclosed primary drive. The inner primary, outer primary, tranny case, trap door, top cover, and pulley shroud are all carved out of 6061-T6 billet. We cut no corners to make this premium drivetrain look like Tiffany jewelry and take punishment from a big inch motor.

    the art of balance: low and centered

    In 2001 we introduced Right Side Drive (RSD) for ground-up, wide tire customs. Any primary drive setup could be used in conjunction with RSD, but there was a problem. Actually not a problem but more like an opportunity. Using a left side drive primary in conjunction with RSD left a gaping hole between the inside of the primary and the left side of the transmission case - the space once occupied by the left side drive pulley. Our new DSSC primary slams the clutch inward 2.3-inch into the space once occupied by the pulley - thus the phrase SLAM CLUTCH.

    While we were slamming the clutch inward, we rotated the starter down into the vacant space behind the transmission case - thus the phrase DROP STARTER. Lowering the starter in the chassis permitted seat heights to be lowered up to 2.5-inch. It also cleaned up the left side view profile.

    DSSC is a complete drivetrain unit consisting of a Right Side Drive transmission and an enclosed primary drive. The inner primary, outer primary, tranny case, trap door, top cover, and pulley shroud are all carved out of 6061-T6 billet. We cut no corners to make this premium drivetrain look like Tiffany jewelry and take punishment from a big inch motor.

    DSSC is a complete RSD drivetrain system and is compatible, without modification, with Daytec, Rolling Thunder, Dakota Thunder, and similar RSD Softail and Hardtail frames with zero engine offset and a left tranny offset. The offset is built into the inner primary - no spacer required. DSSC is set up for 240/250 tire applications using a 1-inch belt. 280 and 300 tire applications are possible with a 530 O-ring and an offset sprocket, call for details.

    DSSC Features:

    RSD6 6-speed gearset with 2.3-inch shorter mainshaft
    43 tooth sprocket-basket with 9 friction plates
    28 tooth motor sprocket - no compensator
    88 pitch 428-2 double row chain
    O.E. type chain adjustment and shoe
    Stock-like 1.54 ratio primary reduction
    Doweled top cover for positive location
    Compatible with Spyke starters (not included)
    66 tooth ring gear for big motors
    No jackshaft on the starting system
    Hydraulic clutch actuator has a 1.5-inch piston
    Mechanical clutch actuator compatible with stock cables
    With or without neutral switch
     
  20. Throttle

    Throttle Member

    Joined:
    May 2, 2009
    Messages:
    193
    Likes Received:
    2
    Trophy Points:
    0
    Location:
    Ballwin, MO
    My Bike(s):
    BullDog 2007
    My 5th gear is only effective above 60 mph. It just seems to get louder and louder. I changed the transmission fuild to Spectro 75/140. The transmission was very quite for the first 2,500 miles, but it is getting loud again. I have 14,500 miles - 2007 Bulldog2007. Unfortunately, i do like to jack rabbit occasionally up to 60.
     

Share This Page