Low speed rattle/shake

[SixShooter14]

I trailered my bike 1500 miles and something has come loose. Question is...what?

When i arrived in Montana (actually along the way) I noticed the front and rear crash bars were getting loose. I tightened them and began checking other things. Carb, intake, exhaust flanges, muffler clamps, mounts, heat shields, floorboards, hwy pegs, horn, engine mounts, shifter linkage, etc. Found several loose fasteners but nothing broken or missing.

Everything was great for about 300 miles of riding. Then i noticed a rattle/knock that sounded like it was from the front end. It's only noticeable below 30mph and only when accelerating. But it gets worse when I lug the engine a bit. There is also a small clunk when hitting bumps. I pulled the windshield and saddlebags off with no change.

I'm thinking the lower engine mount may be the culprit. I noticed the rubber was coming apart and falling out over the winter. But would it only now start making noise and does this sound like a worn out mount?

Any advice or things to check that I may have ocerlooked? Thanks

[SixShooter14]

Oh...also. The front caliper bolts are all tight. But the right caliper rocks a very little bit while the left doesn't wiggle at all. Which one is correct and would that small wiggle cause the rattle?

[thumper 823]

Confused-
Did you notice this on a trailer?
Is it the trailer?

Or-
Check-   front rotor, worn caliper bolts will rattle, I use 3M 5200 on them.
Front fender bolts, busted exhaust tabs.

Others will help here.

[SixShooter14]

Confused-
Did you notice this on a trailer?
Is it the trailer?

Or-
Check-   front rotor, worn caliper bolts will rattle, I use 3M 5200 on them.
Front fender bolts, busted exhaust tabs.

Others will help here.

the loose fasteners were noticed on the trailer last week. But the current rattle appeared yesterday after riding about 100 miles a day for the last 3 days. I've tapped on pretty much everything with the rubber mallet and nothing rattles or shakes. It's only during that brief moment when I'm easing out on the clutch getting to speed... Maybe clutch related? Idk

[Hossamania]

Replace the front motor mount, especially if it is missing pieces of rubber. Check your lower fork tube mount bolts, make sure one or both are not broken.
Check under the tank and make sure the coil isn't loose. The headlight trim ring is known to rattle.
I had a rattle for quite a while, couldn't figure it out, one day something went flying off the bike, never figured out what it was, problem solved!

[SixShooter14]

Replace the front motor mount, especially if it is missing pieces of rubber. Check your lower fork tube mount bolts, make sure one or both are not broken.
Check under the tank and make sure the coil isn't loose. The headlight trim ring is known to rattle.
I had a rattle for quite a while, couldn't figure it out, one day something went flying off the bike, never figured out what it was, problem solved!

coil is tight, the headlight trim isn't loose to the touch or to a tap with the hammer (but I'll give the screw a quick turn) the fork tube mount bolts and both caliper bolts are tight, but again the right caliper does wiggle the slightest amount. Fender is tight as well, but the trim is a little loose, it could be that. But I don't know how to tighten the fender trim (weatherstrip adhesive? But it's on a painted surface, acid free silicone, Idk) I could just shove a piece of rubber under the trim and see if that solves it.

[Flhfxd]

Check the gas tank through bolt up by the triple tree. It might need a little more tension if you've had it off recently...and I believe you have to do your top end?

[SixShooter14]

Check the gas tank through bolt up by the triple tree. It might need a little more tension if you've had it off recently...and I believe you have to do your top end?

I already pulled the tank and dash off to check the intake bolts and upper engine stabilizer thing. They are all good. I also shoved a piece of rubber under the fender trim and that didn't help.

I noticed the rattle also occurs when rolling over a bump at low speed (maybe high speed too and I just don't hear it). It sounds like the same source, i just don't know what that source is. I can't physically move the engine in the frame, so I'm not sure if the lower mount is indeed the problem. But I'm going to change it anyway.

[Hossamania]

Check the rear bumper, they are prone to breaking. Sound travels, strange things happen.
Does it make noise going over bumps while braking slightly or even moderately? This takes the caliper out of the equation if so.

[JW113]

Pinpointing noises is like playing whack-a-mole. Since your bike is a '97 (23 years old), when was the last time you replaced the transmission mounts? When mine went bad, they made sounds exactly as you are describing.

-JW

[Hybredhog]

  Lower pinch bolt on triple tree may have broke, and the head part is retained And bounces off the shroud ? Very common on FLST's, but I don't have a RK in here right now to see if its the same situation.

[JW113]

Yep, had that happen. After that, always use grade 8 bolts on lower clamp. Never broke after that.

-JW

[kd]

I was chasing a noise exactly like you describe and a Harley tech buddy (someone I trust) told me the front caliper bushings were a problem in that vintage. Tough to find so they just change them. They actually stocked them for that reason.   As you know, they need to float but not bounce and clunk.  Maybe try a towel on the top of the fender and a small bungee or the like to support them.  Take a short putt on a rough stretch and see if it'll calm down.

[Flhfxd]

front lower rubber engine mount...?

[SixShooter14]

Thanks for the replies, I'll look into those things.

front lower rubber engine mount...?

it's definitely worn out as there are little rubber pieces flaking off. I just wasn't sure if it would cause the clunking. And once cruising down the road there are no extra noises or vibrations. But I will be replacing it regardless.

[hbkeith]

The rattle started while your bike was on a trailer being hauled ? how was bike strapped down

[Flhfxd]

Thanks for the replies, I'll look into those things.

front lower rubber engine mount...?

it's definitely worn out as there are little rubber pieces flaking off. I just wasn't sure if it would cause the clunking. And once cruising down the road there are no extra noises or vibrations. But I will be replacing it regardless.

This could also lead to excess stress on the exhaust pipes. Eventually could crack at or near the mounting point.

[SixShooter14]

The rattle started while your bike was on a trailer being hauled ? how was bike strapped down

no, the rattle started after 300 miles of riding.

[SixShooter14]

Thanks for the replies, I'll look into those things.

front lower rubber engine mount...?

it's definitely worn out as there are little rubber pieces flaking off. I just wasn't sure if it would cause the clunking. And once cruising down the road there are no extra noises or vibrations. But I will be replacing it regardless.

This could also lead to excess stress on the exhaust pipes. Eventually could crack at or near the mourning point.

When I got the bike, the front header pipe was cracked at the mounting flange. I bet it could be from that.

[SixShooter14]

Problem solved!!

I went ahead and ordered a new motor mount and was looking it over the parts diagram and noticed there's a little triangular plate between the engine cases and the rubber mount.

I had checked the big bolt that goes through the rubber but had missed the 2 that go through the actual case. Sure enough, one had lost the nut and the other was loose. So I got a new nut and with a dab of loctite, they are tightened back up and the clunk is gone.

Thanks for all the help. I will still change out the worn rubber mount next week as there's chunks of rubber coming off this one.