HarleyTechTalk

Technical Forums => General => Topic started by: topcat3815 on February 20, 2021, 04:28:08 PM

Title: Neutral rattle
Post by: topcat3815 on February 20, 2021, 04:28:08 PM
I have a 2014 FLHTK has the dreaded neutral rattle, has any one came up with the fix for this. I have already tried all the different trans. lubes with no help. If changing gears or shafts will fix it I will do it, I just need to know which ones. Thanks for all replies.
Title: Re: Neutral rattle
Post by: thumper 823 on February 20, 2021, 07:00:58 PM
R U sure it is NOT a clutch rattle?
Title: Re: Neutral rattle
Post by: kd on February 20, 2021, 07:07:58 PM
Care to share any info like mods or cams etc?  Does it have a tune (or tuner) ? What is the idle rpm? Mileage?
Title: Re: Neutral rattle
Post by: Scotty on February 20, 2021, 10:54:48 PM
Quote from: topcat3815 on February 20, 2021, 04:28:08 PM
I have a 2014 FLHTK has the dreaded neutral rattle, has any one came up with the fix for this. I have already tried all the different trans. lubes with no help. If changing gears or shafts will fix it I will do it, I just need to know which ones. Thanks for all replies.

Harley know about it and said it's just gear lash and normal.
If you really want to get rid of it put a Baker Grudge box in and the noise will be gone.
Title: Re: Neutral rattle
Post by: thumper 823 on February 21, 2021, 01:47:06 AM
If you are in Neutral there is still quite a few things rotating in there.
Will this do the noise with the clutch lever pulled in?
Title: Re: Neutral rattle
Post by: smoserx1 on February 21, 2021, 03:52:22 AM
QuoteIf you are in Neutral there is still quite a few things rotating in there.

Exactly. In neutral all the gears ride on the shaft via bearings but are not  coupled to the shaft, so you have all the bearings spinning and making noise.  Drop into first gear and that particular gear becomes coupled to the shaft (now rotating with it) and no thus longer spins on the bearing.  It is pretty much normal and works this way on a car transmission also (both trannys are constant mesh).  Certainly not worth trying to fix.  One Solution (if you do this):  Quit shifting into neutral every time you come to a  stop.  Only do it if you are waiting for a train or a drawbridge.
Title: Re: Neutral rattle
Post by: Pirsch Fire Wagon on February 21, 2021, 05:02:48 AM
Without a doubt, the Cruise Drive, all of them, including the third Gen in the 17 and later sound like Concrete Mixers.

On the other hand, some make no noise at all. Go Figure. Just about anything from the Door Bearings to the Clutch Hub can generate noise. The Clutch is key in diagnostics. Does it do it with the Clutch engaged in Neutral? That's an indicator of Door or Final Drive Bearings or even a Pressure Plate from a weak spring. Even a worn set of plates will cause rattles.

If the noise is not hampering performance, I would let it ride rather than installing a Grudge Box. That's a LOT of $$$ for a rattle. Unless you're OCD. And they make Medicine for that.

The 2014's don't have the Gear Aneiling problem like the 17's and later, so Gears are probably not an issue. But, Shaft Caged Bearings can be. I've had retaining split rings fall out and been eaten by the Gearset causing noise as the gears vibrate on the Shaft.

You may want to consider pulling the Gear Set and disassemble it and have a look see.

The possibilities are literally endless. The 3rd Gen, in addition to the Gear Annealing and Shifter Fork Heat, Coking have issues with the 1st Gear Scissor Gear making marbles. Another overlooked item is the Shifter Shaft Bearings. They Suck. I remove them and put a dimple in them to prevent the rattle. You can pack them with grease but the noise returns in just a few miles.

Hope you find it.
Title: Re: Neutral rattle
Post by: topcat3815 on February 21, 2021, 05:19:57 AM
My bad I should have given more specifics, rattles after its warmed up with bike in neutral with clutch lever out, goes away when I pull clutch in, bike has 103 engine with headwork , cam and stage one AC, aftermarket exhaust with power vision tuner and target tune and 32 tooth man of war compensator. Bike runs great and it has had the neutral rattle since I bought it in 2015. Thanks for all replies
Title: Re: Neutral rattle
Post by: topcat3815 on February 21, 2021, 05:25:19 AM
Bike has 24000 miles on it
Title: Re: Neutral rattle
Post by: smoserx1 on February 21, 2021, 06:03:41 AM
QuoteMy bad I should have given more specifics, rattles after its warmed up with bike in neutral with clutch lever out, goes away when I pull clutch in
That should tell you something right there.  When you pull the clutch in the transmission input shafts quits rotating and so do all those bearings.  My bike has a 5 speed and has almost ten times the mileage yours has.  It makes a whir when in neutral with the clutch out and yes it is far more noticeable when everything is hot.  It has been like that as long as I can remember.  To me it is normal, just like the jackhammer loud valve train I noticed on the bikes maiden voyage home.  just ride it and enjoy...it is a motorcycle.
Title: Re: Neutral rattle
Post by: kd on February 21, 2021, 07:45:18 AM
My point of asking about mods, idle speed and mileage etc was to find out if the engine is at all hunting (loping).  It`s good to hear it occurs when the oil is hot and thin only.  Is the idle speed high enough?  What cams do you have and what are the idle characteristics?  A lope in the idle will add and extract power from the gears and can cause the clack and rattle.  Idle in the range of 1050 rpm should be smooth unless the cam influence causes a lope.  Any clacking of the gears at the time of an engine hunting sequence will be normal.  Some transmission designs (small radius gears) are susceptible to it.  One of the things Baker did to combat this in the GrudgeBox was use larger diameter gears. 

I remember the GM stick shift 4 speed in the early 70's had a rubber hubbed gear on one shaft to take up the slack in a softer way that didn't make noise.  That became a service item because they would get pounded out over time.  They eventually redesigned the gearbox to eliminate the need for it. (like Baker did)
Title: Re: Neutral rattle
Post by: Dan89flstc on February 21, 2021, 12:34:32 PM
Quote from: smoserx1 on February 21, 2021, 06:03:41 AM

When you pull the clutch in the transmission input shafts quits rotating and so do all those bearings.   

I disagree...

With a wet clutch, pulling in the clutch lever will not stop the mainshaft (input) from rotating.

The only way you are going to stop the input shaft from rotating is to drop the transmission into gear.
Title: Re: Neutral rattle
Post by: Scotty on February 21, 2021, 01:09:13 PM
Go read M-1304 in the service bulletins it will tell you about the backlash and pulling the clutch in and everything.
Nothing that anyone here is talking about will fix it so don't waste your time.
1000's of big twins out there with the neutral rattle and been around since 2007

neutralrattle.jpg
Title: Re: Neutral rattle
Post by: FLSTFIDave on February 22, 2021, 04:09:36 AM
Got to love it.  Harley puts out a service bulletin to say the rattle is normal.

Did Harley learn to say its normal when a customer has a problem from the Dealer, or did the dealer learn from Harley.

I would be wealthy if I had a dollar for every time I was told something was normal.
Title: Re: Neutral rattle
Post by: smoserx1 on February 22, 2021, 05:02:27 AM
QuoteI disagree...

With a wet clutch, pulling in the clutch lever will not stop the mainshaft (input) from rotating.

Yes Sir, you are correct.  My bad...Steve
Title: Re: Neutral rattle
Post by: kd on February 22, 2021, 06:23:35 AM
It may be normal, as in too hard or too much trouble to fix and that is what the bulletin really says. The knock comes from the cadence in the idle of the engine and that's why it only reveals itself then.  It comes from gear shake caused by the rpm rocking (hunting) from power on to power off.

As previously mentioned, some designs reduce gear diameters to fit a transmission into more confined spaces. Those smaller gear diameters inherently then mesh with fewer teeth on the other matching gear and consequently are more likely to do this. (there is less area for contact and oil cushion to silence the gear "slapping" the other gear) That is the clacking drive line slack noise you will hear as you apply and release the throttle when you are riding. It will also be accentuated by a rough idle like the loping one everybody wants their Harley to sound like or that ratty drag bike sound produced by the cam specs on some high output builds.  That is your complaint, the idle rattle. 

You didn't answer the idle speed question. It may be set too low and the rocking of the idle speed is bringing it out. Try just easing the throttle on enough to lift the rpm ever so slightly (50 - 100 rpm) and you will see it goes away.  Idle speed called  for is usually 1050 and for a reason.  It activates your charging system and keeps the charge above 12 volts (due to the draw of daytime lights etc.). It also improves the response off idle when adding throttle to pull away. I doubt the way it brings out the gear noise was a consideration in that idle spec but IMO it is a factor in the gear noise in many cases. If set too low, restoring proper idle speed can reduce or silence the idle gear noise.
Title: Re: Neutral rattle
Post by: topcat3815 on February 22, 2021, 09:38:52 AM
My bike idles at around 1050 when warmed up I can add some revs and it will go away, Thank you for your replies, I can live with it just thinking maybe there was  a definite fix without just throwing parts at the rattle.
Title: Re: Neutral rattle
Post by: kd on February 22, 2021, 11:14:57 AM
 :up:
Title: Re: Neutral rattle
Post by: Scotty on February 22, 2021, 03:25:22 PM
Quote from: kd on February 22, 2021, 06:23:35 AM
It may be normal, as in too hard or too much trouble to fix and that is what the bulletin really says. The knock comes from the cadence in the idle of the engine and that's why it only reveals itself then.  It comes from gear shake caused by the rpm rocking (hunting) from power on to power off.

My mate has a 2007 that rattles and a 2014 that whines and his son has a 2016 that is quiet.
Luck of the draw with slack manufacturing tolerances I think.
Title: Re: Neutral rattle
Post by: kd on February 22, 2021, 05:10:04 PM
I've had a couple new ones that were whiners that got better as they wore in. The GrudgeBox I am running now was one and now (even with the straight cut gears) it is quieter than the others.  It took a few thousand miles and the instructions said to expect it. I believe that type of whine was pure gear noise before break in.  I never used anything other than a good 75/140 syn gear oil including the GrudgeBox.  In that I have Spectro heavy duty Platinum 75/140 syn as recommended.
Title: Re: Neutral rattle
Post by: hogpipes1 on February 27, 2021, 12:38:51 PM
A friend just bought a 2015 ultra with 7k ,does it have the same issue as the others with a neutral rattle?
Title: Re: Neutral rattle
Post by: kouack on February 27, 2021, 01:01:33 PM
Quote from: hogpipes1 on February 27, 2021, 12:38:51 PM
A friend just bought a 2015 ultra with 7k ,does it have the same issue as the others with a neutral rattle?

hit and miss, depends!
Title: Re: Neutral rattle
Post by: Scotty on February 27, 2021, 09:42:37 PM
Quote from: hogpipes1 on February 27, 2021, 12:38:51 PM
A friend just bought a 2015 ultra with 7k ,does it have the same issue as the others with a neutral rattle?

2007 to all current models can have it even the 2021 models.
Luck of the draw and makes no difference to how the bike runs and rides.
Title: Re: Neutral rattle
Post by: BigT on February 28, 2021, 04:29:10 AM
My 2012 has a neutral rattle.  I installed a louder exhaust system and it went away.
Title: Re: Neutral rattle
Post by: Deye76 on February 28, 2021, 05:24:53 AM
"In that I have Spectro heavy duty Platinum 74/240 syn as recommended."

You have a source for that? Thanks
Title: Re: Neutral rattle
Post by: kd on February 28, 2021, 05:59:12 AM
Quote from: Deye76 on February 28, 2021, 05:24:53 AM
"In that I have Spectro heavy duty Platinum 74/240 syn as recommended."

You have a source for that? Thanks

:oops:  Sorry Deye, it appears I fat fingered that and didn't notice.  :embarrassed:  It's 75-140 and now I can't go back to edit it.  May if a mod sees this they will help out.  :teeth: