FXD vibration problem cured - $10 materials : V-Twin Forum: Harley Davidson Forums
» Sponsors

» Insurance
Go Back   V-Twin Forum : Harley-Davidson Motorcycle Forums > General Discussion Forums > Harley-Davidson Dyna
New User? Register Forgot Password

Reply
 
LinkBack Thread Tools Display Modes
Old 07-07-2005, 12:52 AM   #1 (permalink)
IronButt
 
Join Date: Jan 2003
Location: Wichita, Kansas
Posts: 1,176
84FXRP wants to know Dino or Syn?
FXD vibration problem cured - $10 materials

Sorry for the long post, but I have cured my Dyna’s vibration problem for about $10 in materials and I thought others might benefit from my approach.

I have a 2005 FXDI with a HD 95 inch Stage I kit.

Like some others on the Forum, my bike had, what I consider, excessive engine vibration transmitted to the handlebar, foot pegs, and seat. The vibration was especially evident below 3000 rpm. At idle, the handlebars jumped around excessively.

I followed the Service Manual procedure for vehicle alignment in an attempt to reduce the vibration. Alignment includes loosening (but NOT removing) ALL the motor mount attachment bolts, and then running the motor for 5 seconds during which allow the mounts to align themselves to the frame. The motor mount attachment bolts are then retorqued to spec. The procedure helped a little, but did not cure the problem. I also looked at other changes that might address the vibration problem such as “Bar Snake”, different length handlebars, handlebar mount bushings, etc. All these are Band-Aids on the fundamental problem of too much vibration.

A few weeks later I was thinking about the motor mounts and the alignment procedure and was struck by the cause/cure of the vibration problem. Any elastic motor mount, like the Dyna’s, has a limit to how much vibration it can absorb. Engine movement in excess of this limit is transmitted through the frame to the handlebars, foot pegs, seat, etc as vibration.

What struck me was that when I did the alignment procedure and the mounting bolts were LOOSE, there was a gap between the mount and the frame. Tightening the mounting bolts caused my front motor mount to be PULLED forward to the frame as the mounting bolts were tightened. I noticed that when the mounting bolts were torqued, the frame was also deflected somewhat.

THE ELASTIC TRAVEL OF MY MOTOR MOUNTS WAS LARGELY USED UP JUST BY BOLTING THE MOTOR MOUNT TO THE FRAME.

Any movement of the motor would not be absorbed by the mount – the elasticity of the mount is already used up before the motor is even started. Hence any engine movement is transmitted to the frame and is felt as a vibration. This would also explain premature failure of Dyna motor mounts – they are under stress to begin with.

My solution was to shim the gap between the UNSTRESSED front motor mount and the frame. THE ENTIRE INHERENT ELASTICITY OF THE MOUNTS IS NOW AVAILABLE TO ABSORB ENGINE MOTION. MY VIBRATION PROBLEM WAS GONE!

EDIT ---------

Try this site for photos: http://spotks.blogspot.com/

EDIT --------


Picture “A” shows the gap between the unstressed front motor mount and the frame of my bike – it is almost 0.2 inches. The solution is to shim this gap.

Picture “B” shows my test where I used washers as shims to test my theory. Result - excessive vibration is GONE. The bike is very smooth and the handlebars don’t jump around at idle.

Picture “C” shows the final result. I cut some brass shim stock to fit and used longer bolts to accommodate the shim’s thickness.

Picture “D” shows a scissors jack and block of wood I used to hold the engine up when I had the mounting bolts removed. I had my wife steady the bike and hold it level while I worked on the mount.

Picture “E” shows the shim stock I made and the bolts I used. The stock HD fasteners for the motor mounts are chrome plated, grade 8, socket head screws, 3/8 inch – 16 tpi – and 1 1/8 inches long. [CORRECTION: THE 2005 PARTS MANUAL LISTS THE BOLT LENGTH AS 1 1/8 INCH, THE MEASURED LENGTH IS 1 1/4 INCH] I obtained quality grade 8 bolts, (local caterpillar dealer) slightly longer than stock, to accommodate the shims and still retain the same purchase in the mount


EDIT ---------------

See "Thorns" great suggestion at post #30 to simplify this process.

EDIT --------------


Some Hints:
--- Don't force shims into the gap, you don't want to create a problem in the opposite direction.
- Have a Service Manual available for the alignment procedure.
- When initially measuring the frame to mount gap DO NOT LOOSEN THE REAR MOTOR MOUNT BOLTS. You want to determine the total mount to frame gap.
- After you shim the front mount, be sure to do the alignment procedure in the Service Manual as the rear mount now will need to be able to align itself.
- Be sure to keep the bike VERTICAL when you are working on these mounts. I attach a level to the front and to the rear brake disks to make sure the bike is level.
- My bike tracks straight, I did not need to mess with the alignment adjustment under the tank.

Last edited by 84FXRP; 02-08-2006 at 02:22 AM.
84FXRP is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 07-07-2005, 01:26 AM   #2 (permalink)
IronButt
 
Join Date: Apr 2004
Location: Extremely Grateful in FL
Posts: 6,982
GrayRider is reading this now saying WTF is this?
Brilliant! I've always suspected that an alignment problem was the culprit. This makes perfect sense. Most Dynas don't vibrate until some alteration is made to the motorcycle. (ie exhaust, air filter, etc.) Evidently, the MOCO doesn't do a good job of properly shiming the front mount. Rather, they train their dealers to give us a song and dance of how that everything is normal. OUTSTANDING JOB!!!


H-D's design is not flawed, just the one's implementing it.

Somebody give this man a cigar!

Last edited by GrayRider; 07-07-2005 at 09:11 AM.
GrayRider is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 02:17 AM   #3 (permalink)
Go Sox
 
Join Date: Apr 2004
Location: Massachusetts
Posts: 52
Jake217 wants to know Dino or Syn?
Wow!

Hey 84FXRP,

Don't apologize for the length of your post. That is great stuff and I don't even have a vibration problem. Your time and effort to post this info will be a valuable addition to this site.

Nice Job.
Jake217 is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 02:26 AM   #4 (permalink)
Doing time, behind bars!
 
The_Snowman's Avatar
 
Join Date: Sep 2004
Location: Cedar Creek, Queensland
Posts: 1,479
The_Snowman wants to know Dino or Syn?
84FXRP,
I have a Softail and this doesn't apply to me, but I can appreciate the amount of effort you have put into solving this problem. To document this, as you have, which is quite an effort in itself, and provide it to all members shows what this forum is all about. As said by GrayRider, an OUTSTANDING JOB, well done.
You have my vote added to your reputation and quite a few others I suspect, as you are Off The Scale, congratulations and thanks on behalf of all who take the time to read your excellent post, John
__________________
Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so. Douglas Adams (1952-2001)

Canadian by birth, Australian by choice!

2004 Softail NON Standard
Deuce Rear Wheel 17" x 4.5"
Fatboy Front Wheel 17" x 3.5"
D&D Fatcat 2-1 Exhaust
ThunderMax with Autotune
Arnotts Air Suspension
The_Snowman is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 02:31 AM   #5 (permalink)
FNG :)
 
Join Date: Dec 2004
Location: Phoenix
Posts: 19
Johnny1 wants to know Dino or Syn?
Excellent post!
__________________
"Big hitter, the Lama"
-C. Spackler
Johnny1 is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 03:08 AM   #6 (permalink)
Finally living my dream
 
Join Date: May 2005
Location: Jackson, WI
Posts: 220
intechpc wants to know Dino or Syn?
Anyone know if Harley releases TSB's (Technical Service Bulletins) like auto manufacturers do? This seems to me like something that should be included in one if they do. Nice work, that info will come in handy if I ever run into that issue.
__________________
2001 Dyna Super Glide Sport (FXDX)
MSF Certified
HOG Member
intechpc is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 09:16 AM   #7 (permalink)
IronButt
 
Join Date: Apr 2004
Location: Extremely Grateful in FL
Posts: 6,982
GrayRider is reading this now saying WTF is this?
Maybe this thread should be made a sticky.
GrayRider is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 11:00 AM   #8 (permalink)
Registered User
 
Join Date: Nov 2001
Location: Jacksonville Fl
Posts: 1,496
Kags wants to know Dino or Syn?
Good stuff, but what about the guys that have no gap? For the folks that find the gap please try the above.
Kags is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 11:02 AM   #9 (permalink)
IronButt
 
road_king's Avatar
 
Join Date: Oct 2004
Location: Maryland
Posts: 1,799
road_king wants to know Dino or Syn?
Very informative post. Thanks for sharing the information!
road_king is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 11:11 AM   #10 (permalink)
CrazierThanAShi*houseRat
 
Join Date: Dec 2004
Location: Northern New Jersey
Posts: 101
BlackDevil96 wants to know Dino or Syn?
VERY informative... Nice work!
BlackDevil96 is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 11:12 AM   #11 (permalink)
pws
IronButt
 
Join Date: Apr 2005
Location: Massachusetts
Posts: 344
pws wants to know Dino or Syn?
Quote:
Originally Posted by intechpc
Anyone know if Harley releases TSB's (Technical Service Bulletins) like auto manufacturers do? This seems to me like something that should be included in one if they do. Nice work, that info will come in handy if I ever run into that issue.
Seems like they do but they are a SECRET - never to be seen by those of us who actually OWN their products unless they are "leaked"......
pws is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 01:35 PM   #12 (permalink)
Seasoned Rider
 
Join Date: Apr 2004
Location: Lexington, NC
Posts: 87
swicegk wants to know Dino or Syn?
Great post 84FXRP, A couple of questions. When doing the alignment procedure, do you loosen all 4 bolts on the motor mounts or just the 2 that actually tighen on the frame. I have the service manual but this is unclear to me. Also did you only shim the front mount? thanks
swicegk is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 02:17 PM   #13 (permalink)
Infrequent Poster
 
dwarthog's Avatar
 
Join Date: Apr 2004
Location: Oklahoma City
Posts: 1,662
dwarthog wants to know Dino or Syn?
You sir, are a by god genuis, that is the most outstanding solutions I have ever seen... Sorry for the Gump ripoff.

Excellent display of diagnostic skills and problem solving.

I don't own a dyna, but if I did, I would be planning on doing some checking tonight!

BTW, perhaps you should consider putting together a package with instructions to make yourself a couple of bucks. You won't get rich most likely, but you can get some extra coin for some shiny stuff!

Regards.
dwarthog is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 02:30 PM   #14 (permalink)
This space is blank
 
DCRANER's Avatar
 
Join Date: Aug 2004
Location: NJ
Posts: 1,029
DCRANER wants to know Dino or Syn?
84FXRP, EXCELLENT THINKING & DOCEMENTATION!!

I recently posted a thread "Vibration @ 42 MPH", and I will check this for sure.

Once again, thank you.
DCRANER is offline   Reply With Quote Quick reply to this message
Old 07-07-2005, 03:21 PM   #15 (permalink)
IronButt
 
Join Date: Jan 2003
Location: Wichita, Kansas
Posts: 1,176
84FXRP wants to know Dino or Syn?
Quote:
Originally Posted by swicegk
.... A couple of questions. When doing the alignment procedure, do you loosen all 4 bolts on the motor mounts or just the 2 that actually tighen on the frame. I have the service manual but this is unclear to me. Also did you only shim the front mount? thanks
I agree, the Service Manual is not real clear here. The Service Manual section on motor mount REPLACEMENT (end of section 2) shows installing the frame to mount bolts and THEN the bolts that run through the mount. Earlier, when I was aligning my bike per the Service Manual, I did loosen the frame to mount bolts AND the bolts that run through the mount itself.

However, when doing this motor mount shim exercise I have been loosening just the the bolts that attach the mount to the frame. This has resulted in an acceptable level of vibration (like a Harley should have :-) ) to me. I certainly don't think loosening the other bolts would harm anything, and most likely would make the vibration less.

I only shimmed the front mount. With the front mounting bolts loosened, the rear mount (transmission) should not be under stress so the gap between the front mount and the frame should represent the ENTIRE distance you need to shim.

THAT IS THE REASON YOU DON'T WANT TO LOOSEN THE REAR MOUNTING BOLTS WHEN YOU ARE WORKING TO DETERMINE THE SHIM THICKNESS. Once the shims are in place, THEN the alignment process will require both the front/back motor mount bolts to be loose.

The sissors jack was pretty handy to place (lift) the engine at the proper height to measure/add shims. The bolts should turn in by hand. If the bolts are binding, then the mount and frame holes are not lined-up properly and you need to "tweak" the motor position by raising/lowering the jack.

Things should go together EASILY, if not, then take a minute to figure out what the problem is.
84FXRP is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the V-Twin Forum : Harley-Davidson Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. WE WILL SEND A CONFIRMATION EMAIL TO THE ADDRESS YOU PROVIDE. If the email address is NOT VALID, you will not be given access to the system!
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On


Powered by vBadvanced CMPS v3.2.2

All times are GMT -5. The time now is 02:16 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO 3.6.0
(C)2001-2012 V-twinForum.com All Rights Reserved (C)2001- V-twinForum.com All Rights Reserved
Motorcycle News, Videos and Reviews
Honda Grom Forum Harley Davidson Forum Honda 600RR Forum Kawasaki Forum Yamaha R6 Forum Yamaha FZ-09 Forum
1199 Panigale Forum Roadglide Forum Honda CBR1000 Forum Vulcan Forum Yamaha R1 Forum Yamaha R3 Forum
Ducati Monster Forum Harley Forums Honda CBR250R Forum ZX10R Forum Star Raider Forum Yamaha Viking Forum
Suzuki GSXR Forum V-Rod Forums Honda Shadow Forum Kawasaki Motorcycle Forum Star Warrior Forum KTM Duke 390 Forum
SV650 Forum BMW S1000RR Forum Honda Fury Forum Kawasaki Versys Forum Drag Racing Forum Ducati 899 Panigale Forum
Suzuki V-Strom BMW K1600 Triumph Forum Victory Forums Sportbikes BMW NineT Forum
Volusia Forum BMW F800 Forum Triumph 675 Forum MV Agusta Forum HD Street Forum Suzuki GW250 Forum
Yamaha Motorcycles Victory Gunner Forum Honda Vultus Forum HD LiveWire Forum Ninja H2 Forum Ducati Scrambler Forum Kawasaki Ninja 250SL Forum