Rear end rumble ...

[Roy]

Hello

Since I had my rear swingarm (2006 streetbob, 27k miles) replaced in July 2007 there has been a very slight rumble from my rear end (!) especially on mildly bumpy road surfaces.

At the time I phoned up the dealer and chatted to a mechanic who advised me to keep an eye on it and report back in if it became worse. 1.5 years later it is starting to get worse.

I am not sure if I should expect a minor amount of rumble from the rear (I have -2" progressives on the rear, so quite firm) and this is just something going (????). When I jack the rear wheel into the air and give it a shake, there is a definate very small amount of movement in the rear end which I expect is partially flexing in the swingarm etc.

Are there any tests for sinwgarm bush wear or rear wheel bearings on way out? Like I say, swingarm and rear wheel were fitted as new in July 2007 (since then done about 21k miles).


Please let me know, Roy

[banquo]

Always difficult to diagnose noises, even when it's your bike, and even harder when they are rolling noises. Your description of 'rumble' sounds more like a rolling noise than a swinging arm noise, unless I'm being misled by your description...
I'd be looking to be absolutely sure where the play is coming from, as wheel bearings do rumble when worn, whereas swinging arm bearing noise wouldn't normally be described as that... More like a knock or rattle on bumps, and probably silent on a smooth road. This from experience on non-Harley swinging arms though, so others might know different, but to me, it sounds like wheel bearings.

One way to check is to grab the wheel front and rear, and try to rock it back and forward relative to the swinging arm. It should be obvious if you're holding both ends of the wheel if it's the wheel that's moving. If you just grab the back of the wheel, you can't tell where the play's coming from.

[Roy]

Thanks Banquo

I was writing the original note and saying rumble and felt this may be misleading, then pressed send ...

The noise is only apparent on bumps (and then really only noticable on smaller bumps/rough road but probably because on big bumps my -2 progressives are busy putting my spine through my head so I don't notice any oddities ), not on smooth road.

More than the noise, its more of a feeling of knocking.

What I was thinking is Oxford HD have offered to take a look, diagnose the problem and then give a goodwill discount on any parts. I might take them up on the offer as I sense this may be something someone who knows what they are on about would take a 20 sec look at the bike and see what the issue is ... my money is on swingarm bushing.

If this is the case, are these painful to replace once the swingarm is off?

Cheers, Roy

[grbrown]

I agree with Banquo about wheel bearings, although the only experience I have had with them failing was my front wheel on an earlier Harley (the races were the same as a Ford car front wheel!).

Harleys have tapered roller bearings (unless they have changed on recent bikes) and a small amount of free play is normal, so it can be difficult to diagnose. If in doubt get advice from a dealer/specialist.

The belt drive can make funny noises, especially if not properly adjusted, as can a chain. I have also had tyres that made strange noises, although not what I would call a rumble in any of these.

[Limey_Dave]

If it's a knock I'd look at the shocks.If the dampers are too weak for the springs they can top out when they extend.
Are the shocks in the standard position on standard swingarm? If the angle has changed then so will the damping.
Check top and bottom fixings are tight and any bushes in place.
Are the fixings standard,some fancy replacements can be under size and bushes will rattle on the bolts.

These are observasions on shocks in general,not specific to your bike.

[banquo]

Not familiar with the construction of your bike Roy, but the Softail has spherical bearings, that are supposed to last for life, unless damaged. There was a post on here recently about possible damage to wheel bearings when driving out a seized axle (brinelling the races from the shock loads) and I guess your swinging arm bearings, could have suffered when the arm was exchanged if there were any issues. Why was the swinging arm replaced anyway? I'm intrigued that the dealer seems to think they have some responsibility for this, and that you reported an issue some time ago...

Your most recent description does sound more like the swinging arm pivot, and if you have play as well, then it's perhaps the most likely. Either way, with the bike up on a bike lift (and secured properly!) you should be able to see where the play is...

[Roy]

Thanks all

Cheltenham HD had a look at my bike and could find nothing. One of their 'mechanics' took the bike for a short ride (it started spitting with rain so he turned back...) and deduced I probably had a problem with my transmission. The head service guy was looking at him like he was nutz.

What the head service guy, Ian, did say is my belt was probably a bit tight however basically he put my mind at rest that I was probably worrying a bit too much. Ian checked my swingarm bushing/bearing, wheel bearings, headstock bearings for tightness and could find no problem. I needed an expert opnion as sometimes feel like i am scratching around a bit, this is generally where the website comes into play so thanks chaps.

On returning home, I did quickly do a check of the bolts on my shocks when I got back and found although I had tightened them I had not torqued them (top is 74iibs and bottom is 35iibs) - the side that seemed to be knocking most (and chipped some of the powder coating of my strut cover) needed most torquing up - so will see how I go over the next day or so.

Cheers, Roy

[Scotty]

Originally Posted by Limey_Dave

If it's a knock I'd look at the shocks.

+1 on that.

Originally Posted by Roy

Thanks all

One of their 'mechanics' took the bike for a short ride (it started spitting with rain so he turned back...)

LOL

[gilesgraphics]

I was just about to say check the belt..

[Roy]

The chap Ian said the belt was a little too tight and that there is a HD tool you can buy, but this was more of an aside something he;d noticed when the bike was on the ramp.

Having torqued up the rear shock bolts, the bike was noticably better today.

Think I am sorted. Thanks for your help

Roy