So i put a new motor mount of the front of my WG. Much better. However....it seems now the rear of the bike is buzzing like a weed eater at all speeds. Lay my hand on the tank at 55mpg and feels smooth but under my seat and to rear of bike is buzzing terribly. My theory is the new mount corrected the sag on the front and now has the rear mount out of wack. I suppose if you replace one you should replace both? I went ahead and ordered a new rear mount and should have it by friday. Went over everything else and can't find any loose or parts making contact anywhere. So anyway.....is this a typical symptom of a bad REAR motor mount? I know its a Dyna and they vibrate. But i don't believe its suppose to buzz like a buzz saw at 60mph.

Honestly I'm getting at wits end with this harley. I thought with 16000 miles it would be in good shape. Evidently its been sitting in a barn covered with a tarp most its life. I think thats the worst thing a machine can do is SIT. I got a nice Memphis Shades Slims windshield picked out if i could only get these harley vibration problems fixed ugh. Seem when i fix one thing another one arises. Selling and buying a Kawasaki even crossed my mind. YIKES

 

I don't know what a bad rear mount feels like or what you are experiencing is symptomatic of, but I doubt that the new rear mount will change things much!... and why I think that is because they don't typically go bad... also, because they are maybe 3-4 times stiffer than the front mount and being so far back from the crank center function more as a pivot and a stabilizer.

 

You are going to have to swap the mount and see what happens.. A failed rear mount can cause vibration, not least because it can cause metal to metal contact with the frame. But other things can cause vibration as well that have nothing to do with the mounts.

Mileage is not a measure of age. HD definitely had a quality problem with the mounts which would be why there are so many premature failures but at the back corrosion is the killer with the rubber debonding due to oxide forming between the rubber and metal.

Fit it and see what happens. Probably a 80/20 chance it will sort the problem.

 

Well, if the bike has been sitting in a barn for most of its life there is probably no doubt that the tire's may have some bad spot's in them from sitting for so long.... I would definitely would dump them and go with new one's, that may be your issues.
I know this for a fact, When I purchased my first Harley 1997 1200S Sportster it had been sitting for a while as well and also buzzed worse than a chainsaw, even though it was rigid mount.
Changed out the tire's and was like a new bike...........
Might want to look into that as it may be your issue..............
So once you change the rear mount as she is still buzzing look at the tire's next.

Live Free = Ride Free...........

 

That's the main reason I'm going to replace it. It's probably detoriated from sitting so much. It's been sitting in a barn with dirt floor with tarp over it. I know from experience that barn dust will eat things up.

What baffles me is I didn't have buzz in the seat before installing new front mount. I know new mounts sit lower than original by 1/4 inch I think. Only thing I can figure is correcting the sag on front has transferred more stress on the rear mount which is already old and worn.

One interesting thing is the dealer said they have NEVER sold a rear motor mount for a dyna. Showed me the computer history and sure enough it was empty.

I also keep thinking I'm being unreasonable. But I rode a solid mount 2003 sporty for 8 years and the dyna is buzzing at 55-65 like my sporty did. I don't think it's unreasonable to expect a rubber mount dyna to run smoother at speed than a solid mount 883.

 

Johnny you have a few threads going here with the same topic. I responded to you on the other but you didn't get back to me. I'm guessing your vibe is low rpm? Do you have a tach? I replaced my rear mount because it was 16 years old and it looked like it was allowing the engine to bottom on the mount, I'm not sure I needed to. You can inspect the mount before you take it off and I would suggest you do to know where your engine is sitting. On the jiffy stand at the rear you can check the clearance between the rear mount and the trans. You can also slide your fingers between the trans and mount to see how it's sitting in there. With a mirror you can check to see of it's sheared partially as well. Replacing my rear mount changed the angle and how the engine sits in the frame. It stopped the engine from bottoming on the rear mount but did nothing for vibrations. The front mount has made the biggest impact on vibrations and stability. I went vibratechnics, I'm not sure how the redesigned stock ones perform. Mine vibes at 2000 and smoothes out at 2200 and is smooth and stable through redline. Did you get any photos of the new front? Is it sitting right on the bike and did you do an alignment? My engine was off 2 degrees after replacing both mounts

 

NO!... far as I'm concerned you aren't being unreasonable!... know exactly what the difference between a solid mount Sportster and a Dyna should be. my dyna is a 06 with over 60,000 on it and with original mounts, still smooth as glass. not talking about those low rpm shakes, I mean once the revs get up past 2000 - 2500 it's eerily smooth! none of those Sportster high frequency vibes at all!... my front mount has sagged so it's just barely touching the acceleration stop and the rear mount has settled to within 1/8" of it... still smooth as glass I'm telling you!... just like a new one!... corrosion isn't a problem here tho... bare metal left outside will take several years to begin rusting...

don't forget to check for frame to mount gap and if there is one to shim accordingly!

 

A different type mount but: We had a thread about aftermarket front mounts on the touring section. After installing urethane mounts,[mine was from Bikers Choice,IIRC-and another guy used a Motion-Pro or whatever]
After install,we noticed a heck of a buzz in foot boards,which WENT AWAY after 20 or 30 minutes riding time. Seems the mount needs some run time to situate itself,I wonder if that could be your problem?

 

Did you install all the front bolts and run the engine loose for 30 seconds so the new MM could place itself? Then you turn the engine off and torque the bolts to spec afterwards.
I notice my read MM was torn because I could literally feeel the engine bouncing whenever I would hit a bump, which became even more pronounced with the wife sitting on the back.

 

Made a new discovery. Apparently the exhaust system is missing a bracket that supports rear muffler. I notice the back muffler bounces around a lot and found there is supposed to be a long support bracket there. I dunno if this contributes to the problem but i have one on order to fix it. I think i really got in over my head buying a used harley someone else has doped around with. Big lesson learned. This thing is gonna run me broke