FXD Vibration Problem Cured - $10 Materials

[BOUTYM]

Good luck on getting anyone remotely related to the MoCo to give a sh!t about vibration, or anything else for that matter. I'm in a battle right now over this and other warranty issues they are refusing to even diagnose, much less fix.

[dynajohn]

My hat is off to you 84FXRP . I have a 03 FXDX that I have fought this vibration problem on since I bought the bike. I thought the vibration level was excessive between 2000 & 3000 RPM from the time I picked the bike up from the dealer. I have to admit the bike has been extensively modified so that contributed to the problem later on. The motor is a 124 based on stock cases which was properly balanced. The bike has always had more vibration than I considered acceptable but the handling problems didn't start until I passed the 110 HP level. When my engine was a 107 C.I. I tried curing the vibration issue with a bar snake, bar end weights, handlebar mount bushings, doing the standard alignment procedure and none of these made any real difference. Hopefully the simple fix you have outlined here will help (assuming I have the same issue). I cured the handling issues when I installed a Sputhe positrac stabilizer kit. I tried everything else to cure a nasty weave at 100 + MPH under full power (works shocks, custom valves & springs in front forks, steering stabalizer, new higher spec tires, steering stem bearings, motor alignment ect ect ect) but it was still there until I installed the Sputhe kit. I don't think the Dyna chassis is as stable as my FXR was but no late model Harley is.

[d1hojo]

I ended up changing out both motormounts and the spacer and the alignment and got rid of some of the vibrations. The thing is that I can't figure out how to center everything on the bike. I have three levels, one for the frame, one for the rear disc and one for the front disc but how do I know when the front end is level?

[84FXRP]

Originally Posted by d1hojo

I ended up changing out both motormounts and the spacer and the alignment and got rid of some of the vibrations. The thing is that I can't figure out how to center everything on the bike. I have three levels, one for the frame, one for the rear disc and one for the front disc but how do I know when the front end is level?

You position the front wheel so that the front brake disk is vertical.

You need to CAREFULLY follow the alignment procedure step-by-step as detailed in the Harley-Davidson Service Manual specific for your year and model bike.

Don't skip steps -

Do EXACTLY what the step directs -

Don't assume a measurement is correct, check it -

Do complete ALL the steps.


Spoke wheels need to be true and cast wheels need their runout checked. Your steering head bearings should be checked and adjusted as necessary.

Check and adjust the rear axle as necessary. The rear axle must be (very accurately) equally spaced in the rear fork - this is important!

With the front brake disk vertical, the rear brake disk should be parallel (should also be vertical) to within 1 degree.

Be sure to carefully note the steps in the procedure when the bolt that attaches the top stabilizer link to the engine mounting bracket is REMOVED, how the top stabilizer link is ADJUSTED, and WHEN and HOW this bolt is reattached.

I use good quality levels, with magnets that hold on to the brake disks, to check my alignment. The Service Manuals calls for using a digital inclinometer for best accuracy. My bike has always tracked straight and the brake disk alignment checked looked good using the levels, so I did not mess with the (top) stabilizer link.

[deano2]

What does it take to make this thread "STICKY"? Needs to be at the top at all times. I'm always glad when someone responds and it comes back to the top ... again, it needs to be "STICKY".

[d1hojo]

Thanks for the reply, I think I did it backwards. I alighned the front to the rear instead of the rear to the front. The bike goes pretty straoght but feels like it is leaning to the left. When it says to raise the back of the bike, does that mean under the frame so the rear wheel is hanging or do you raise the rear fork?

[84FXRP]

Originally Posted by d1hojo

Thanks for the reply, I think I did it backwards. I alighned the front to the rear instead of the rear to the front. The bike goes pretty straoght but feels like it is leaning to the left. When it says to raise the back of the bike, does that mean under the frame so the rear wheel is hanging or do you raise the rear fork?

Raise under the frame (not under the fork).

[wrecker]

just want to say thanks to 84fxrp good work and something I will sort when the bike goes back together. Not only will this help with engine vibs but also help with mount life as well.

[d1hojo]

Thanks 84FXRP, I need to change my name to two times. I seem to have to do everything twice.LOL

[cdog]

I have a shaky 07 FXDSE as well. Mohead1, did the shim help your issues?

A question: If I loosen the nuts one at a time as described in post #30, do I still need to do the alignment procedure? I don't have a shop manual describing it...

If its as simple as looseing a few bolts, running the motor for 5 secs, and tightening them back down, I can do that. The motor is not supported during the alignment, correct?

Thanks.

[84FXRP]

Originally Posted by cdog

I have a shaky 07 FXDSE as well. Mohead1, did the shim help your issues?

A question: If I loosen the nuts one at a time as described in post #30, do I still need to do the alignment procedure? I don't have a shop manual describing it...

If its as simple as looseing a few bolts, running the motor for 5 secs, and tightening them back down, I can do that. The motor is not supported during the alignment, correct?

Thanks.

If you follow the procedure in post #30 you still need to do the alignment procedure.

I would recommend not trying ANY of these procedures without the benefit of the Genuine Harley-Davidson Service Manual specific for your year and model bike. There are SPECIFIC steps and checks for alignment. Accomplish ALL the steps in the order specified - it is not difficult but you need to be careful and thorough.

You are correct that the motor is not supported by a jack during the "idle" portion of the alignment procedure.

[elamey]

2006 Street Bob - I'm a believer. Just did this today. My estimate on the vibration reduction is 25% (mine was never a big shaker anyway). My Harley is starting to ride like a metric....but still be a Harley!! Once I fattened up the AFR with a Teclusion and did this little shim trick....SMOOTH!!!!

My experience: I did the procedure as described in post 30 and sure enough...a gap appeared. I only needed one washer (I bought some grade 8 washers with the grade 8 bolts) on each mount bolt, so mine wasn't that far out of whack, maybe why I only notice a 25% decreas in vibration...but that is still HUGE. Much more comfortable.

Last thing I noticed....my bars shake like a rattler on red bull and starbucks dark roast when I start and idle the bike. After it warms up, the bars don't shake at idle. Is there a difference in the two idles? Fatter fuel? Different timing/rpm? Just wondering.

Thanks for the great post, it was really cool, I was kind of a skeptic until I saw that significant gap. GREAT POST!!

[84FXRP]

Originally Posted by elamey

2006 Street Bob - ... Last thing I noticed....my bars shake like a rattler on red bull and starbucks dark roast when I start and idle the bike. After it warms up, the bars don't shake at idle. Is there a difference in the two idles? Fatter fuel? Different timing/rpm? Just wondering. .....

The handlebar shake on mine is greater cold then it is after warm-up. I figured it was rpm related. My 2005 FXDI bike has the 95 inch kit and HD Stage 1 download.

The Motor Company switched Dynas from OPEN LOOP to CLOSED LOOP fuel injection with the introduction of the 2006 models. My bike does NOT have the "rattler on red bull and starbucks dark roast" shake, perhaps this is due to the differences in open/closed loop systems.

Have you gotten any FI codes set on the oxygen sensors?

[elamey]

I wanted to update...my earlier post said this change only got rid of 25% of the vibration...that was from a short ride. I rod into work and the difference is amazing. There is very little engine vibration now. I would say 10% or so of stock. Thanks again for the great post!!

[tym4brk]

Reviving an old, but very useful thread. I'm in the same boat, excessive vibrations, and I'm mid-way thru the alignment and "Fix" process.

Note: both isolators and the stabilizer were replaced by a shop a month ago. I have had excessive vibration for a while now, most of it was caused by a faulty ignition module, which I've replaced also. Prior, the vibes were at all rpms all the time. Now that the module is good, vibes are mostly at accel and decel. I can get her to settle into a smooth run by varying the engine speed. Off idle I can slowly increase the rpms and the vibes are very noticable as I do this up to a point. Everything shakes in this range, but as I exceed it, it smooths out.

I have my bike level and plumb and I've checked my front isolator and found about 2 washers worth of gap on the top bolt only. To shim it properly I'd need a wedge shape, but for now I have placed two washers in the gap on the top bolt and snugged both of them down. The rear is untouched as of yet. This was my first step.

I then lifted my tank to inspect the stabilizer. I removed the bolt as the FSM said to, and it was difficult to get out. There was a lot of tension on it. This is what it looks like when at rest...



The photo shows it's natural position with tension off of the stabilizer. As you can see, the eye is rearward of the hole it should go in, and also inward. Seems this is under stress all the time when the bolt is installed.

With the stabilizer disconnected my front brake disk is perfectly vertical, the rear one is almost perfect.

So, it seems I need to adjust this stabilizer so it's not under stress. Question is, how? The image in my FSM is of a different year bike, a 1995 I'd say, cuz my stabilizer is slighly different than what's pictured.



Looking into the photo, which "nuts" should I mess with? Seems from near to far there is the isolator, then a nut, then another nut, then another nut, then the other side of the isolator. It's not clear to me which I'm to loosen, and which I am to adjust.

Also, it seems I should loosen the nut holding the stabilizer to the frame on the carb side so I can angle the stabilizer just a bit towards the front, so it's not stressing the bushing in the stabilizer.

Any advice from the experienced would be helpful. I may need to remove my washers so the front isolator is in it's original position, then re-check the stabilizer. It seems all out of whack, tho the bike tracked straight before I messed with any of this stuff. Seems odd the stabilizer has so much stress on it though and could very well explain the vibes I'm having.

EDIT: This Just In...

The front pipe is hitting the frame with the top stabilizer bolt disconnected. This is bad and now I'm wondering if my vibration was the pipe hitting the frame under load to begin with. Could the rear isolator be installed upside down by any chance? I didn't change it so I don't know. The front is obviously a one-way install kinda thing.

EDIT #2:

I put the stabilizer bolt back in and didn't adjust anything, mainly cuz I couldn't get it to adjust, which is probably a good thing. When I unblocked the bike and rest it on the jiffy stand, the front pipe no longer was touching the frame. It's a tight squeeze there, but it doesn't touch.

Seems the way I had the bike shored upright was the problem. I'll spare the details, but just call me numbnutz for now.