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frame vibration

dd1228

Active Member
Between idle and 1800 rpm my flhtc vibrates like crazy. I have tried everything I know including a new front engine mount, both Harley and Velva ride, rebuilt the carb, checked for vacuum leaks, checked the compensating nut on crankshaft, checked primary chain tension. I'm at a loss. I'm afraid to take it to the dealer cause they looked at it once and said it ain't too bad. That it's what Harleys do. Any other ideas out there? It didn't do this a year ago. I have the 95 inch big bore and stage I with 70,000 miles on a 2002 model. Other than the irritating vibration it runs strong.
 
Between idle and 1800 rpm my flhtc vibrates like crazy. I have tried everything I know including a new front engine mount, both Harley and Velva ride, rebuilt the carb, checked for vacuum leaks, checked the compensating nut on crankshaft, checked primary chain tension. I'm at a loss. I'm afraid to take it to the dealer cause they looked at it once and said it ain't too bad. That it's what Harleys do. Any other ideas out there? It didn't do this a year ago. I have the 95 inch big bore and stage I with 70,000 miles on a 2002 model. Other than the irritating vibration it runs strong.

Have you checked the links?

If they are OK, I suggest you check the runout on the pinion shaft. Need to figure if you have a scissored crank.

TQ
 
Do you mean the links on the primary chain? I haven't done that, but I'll try. Any chance the rear engine mounts have gone bad?
 
Do you mean the links on the primary chain? I haven't done that, but I'll try. Any chance the rear engine mounts have gone bad?

No, I meant your stabilizer links. Should have one up at the front of the engine, and one under the tank between the heads. Make sure these are not loose.

The rear end of the engine/tranny is mounted in some rubber isolators that the swingarm pivot shaft goes through. Unlikely this is the problem you are having.

TQ
 
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Yeah, I checked the lower link, actually you loosen it to lift the front of the engine to replace the front engine mount, so I'm sure I tightened it. But I could not get to the top one without lifting the tank. Maybe I'll try that. Why don't you think it might be the rear engine mounts. Did you have experience with that at one time. I'm thinking the front rubber mount wore out, why not the back ones too. Oh well, just guessing. But looking at the shop manual it doesn't appear to be too big a job to replace the rear ones. Just a couple of nuts and remove the swingarm shaft and install the new mounts and re-insert shaft. I might try that this weekend.
 
Yeah, I checked the lower link, actually you loosen it to lift the front of the engine to replace the front engine mount, so I'm sure I tightened it. But I could not get to the top one without lifting the tank. Maybe I'll try that. Why don't you think it might be the rear engine mounts. Did you have experience with that at one time. I'm thinking the front rubber mount wore out, why not the back ones too. Oh well, just guessing. But looking at the shop manual it doesn't appear to be too big a job to replace the rear ones. Just a couple of nuts and remove the swingarm shaft and install the new mounts and re-insert shaft. I might try that this weekend.

The reason the front wears out is that the originals were substandard compared to the one you replaced it with, and the front one is likely to have had oil spilled on it during filter changes. This oil breaks down the motor mount material.

Improved Rubber Motor Mount - Harley Davidson Community

If you are replacing the swingarm isolators, make sure you support the rear of the tranny BEFORE pulling the shaft out of the swingarm. It is not a big job. But I hope you have the Service Manual.

TQ
 
I just spent an hour in the garage trying to figure it out. I lifted the gas tank and I was able to tighten the upper stabilizer link a little bit, but it wasn't really loose. I have the shop manual and I just may try replacing the rear mounts this weekend. I read the directions over and over and it doesn't seem like something I can't do. I'll be sure to support the motor and tranny before pulling swingarm shaft. Thanks for replying, I appreciate it. I'm new to this website and so far it's worked great. I'll let you know what I eventually find out. I sure hope there is a cure for this eventually, cause it sure is a pain shaking like this. And it never used to do this. So something is awry!
 
I just spent an hour in the garage trying to figure it out. I lifted the gas tank and I was able to tighten the upper stabilizer link a little bit, but it wasn't really loose. I have the shop manual and I just may try replacing the rear mounts this weekend. I read the directions over and over and it doesn't seem like something I can't do. I'll be sure to support the motor and tranny before pulling swingarm shaft. Thanks for replying, I appreciate it. I'm new to this website and so far it's worked great. I'll let you know what I eventually find out. I sure hope there is a cure for this eventually, cause it sure is a pain shaking like this. And it never used to do this. So something is awry!

The stabilizer does not need to be "tight" as long as the ends are not loose, meaning the mounting bolts are secure. The top link is used to keep the engine fixed in a vertical plane. The front link is used to keep that vertical plane aligned straight ahead. Read the section in the book about aligning the bike.

TQ
 
I rode the bike to work this morning and since I tightened that upper link most of my vibration went away. HOORAY!!!! Now I'm wondering the end of the links have a rubber bushing















I rode the bike to work this morning and since I tightened the upper link most of the vibration is gone. I wonder if I replace the rubber bushings in the ends of all the links if all my vibrations would go away. What da ya think?
 
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