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Sat Jun 27, 2020 10:15 pm

I have been dealing with a rattle in my stick shift for years.

Years ago I refreshed the shift rod hoping that that would take care of it. It did not. I chalked it up to my inexperience: I must have done something wrong with the refresh. Which still could be true, BUT...

Tonight, I was driving on the highway, and there it was again as always, the stick shift rattling! (really annoying on long trips) I have been trying to narrow down WHEN it rattles at its worst, so I was playing with it a bit (again!) to try to figure where the rattle was coming from. When I grab the stick shift, the rattle goes away. This made sense to me. The vibration is coming up the stick and somewhere the stick is hitting something to make that rattle.
But tonight... I grabbed the stick shift and it went away as usual, but then I grabbed further down the stick to keep the stick from vibrating, but the noise did NOT go away. I repeated this until I realized that when I grabbed the shifter knob, the noise went away, but when I grabbed the stick itself the noise remained!
Then, I unscrewed the shifter knob slightly and the noise diminished.
Then, I unscrewed the shifter knob all the way off and the noise was nearly gone!
I shook the shifter knob in my hand to see if something was loose in there, but no noise.
Since I was driving at night, I had to wait until I got back home to look at the shifter knob closely. It is a stock knob. It is one solid piece as far as I can tell. I cannot see any cracks in it. But it does have a kind of echo chamber underneath where the stick is screwed into it.
I have searched samba for any similar issue, but I have not found any post addressing this.
Rather than immediately just purchase a new shift knob, I am going to try some thread tape around the threads of the stick before I put the knob back on, and maybe not tighten it down too hard.
I don't really understand why or how this rattle is happening just from this knob.
Has anyone else had this issue?????

Sun Jun 28, 2020 5:39 am

I had a similar issue and discovered that both grub screws below the bus on the shift rod were loose. I tightened them up, and the rattle was gone.

Here is a thread that came up recently that might be related:

https://www.thesamba.com/vw/forum/viewtopic.php?t=738533&highlight=

Good Luck - Jeff

Sun Jun 28, 2020 7:47 am

Whaanga wrote: I had a similar issue and discovered that both grub screws below the bus on the shift rod were loose. I tightened them up, and the rattle was gone.

Here is a thread that came up recently that might be related:

https://www.thesamba.com/vw/forum/viewtopic.php?t=738533&highlight=

Good Luck - Jeff

Thanks, Jeff.

But did you also notice that the noise went away if you took the shift knob off?

Sun Jun 28, 2020 9:15 am

I never removed the shift level knob so I don’t know if this would alter what I was hearing. But, from my experience, if I just touched the shift lever, the rattle would stop. And - if I let up on the gas, the noise would stop. But this noise only occurred at highway speeds.

My hunch is that the noise is not related to the shift lever knob. Rather to something under the bus in the shift rod and its linkage which, is being manifest up through the lever - almost like sympathetic vibrations.

Sun Jun 28, 2020 9:35 am

Whaanga wrote: I never removed the shift level knob so I don’t know if this would alter what I was hearing. But, from my experience, if I just touched the shift lever, the rattle would stop. And - if I let up on the gas, the noise would stop. But this noise only occurred at highway speeds.

My hunch is that the noise is not related to the shift lever knob. Rather to something under the bus in the shift rod and its linkage which, is being manifest up through the lever - almost like sympathetic vibrations.

Yes, that has been my notion for many years too, until last night when I took the shift knob off the stick and the noise went away.

I don't understand why.

I haven't tried driving it today yet. I am curious to see if it is still gone. I am also curious to see if the noise stays away if I use some cushion on the threads of the stick where the knob is screwed on (thread tape, etc). I went out to the bus this morning to look at the stick, I was going to try to put one of those kitchen cabinet bumpers on the end of the stick before I screw on the knob to try to absorb some of the vibrations, but the end of the stick shift is tapered and not flat as I had assumed.

Sun Jun 28, 2020 9:51 am

It seems that the knob might act as a weight that amplifies the movement from below. Perhaps when you removed the knob, the slightly less weight allowed the vibrations to dissipate up through the lever. But - this is only a theory. What if you put some Teflon tape on threads to see if it helps absorb the vibration?

And again, from my experience, check the grub screws and see if they’re tight.

Sun Jun 28, 2020 10:19 am

agree on the grub screws but would like to mention how much grease did you use when you did the bushings? I really pack the hell out of them, same with the front shift rod ball and socket too. a lot of guys seem to just barely lube them up

also if the trans was rebuilt with the steel ball in the selector shaft pivot some complain about some shifter rattle but I never noticed it on mine (probably because I use a ton of grease)

I did a thread about worn out shifter levers...how does the lever look? more specifically the pin slot in the front pipe

Sun Jun 28, 2020 10:01 pm

Jeff, I'm surprised that you missed the resonator design on the underside of the shift knob. ;)

The cavernous space in the plastic mold under some shift knobs acts as an amplifier for any minute rattle. Anything from loose motor mounts, to an out of balance engine, to a bent shift coupler can cause vibration. The knob is only turning existing vibrations into sound.

Once you have ensured that all your shifter parts, bushings, and lubricants are in order, and you promise your shift rod and engine alignment are good, filling the space in the shift knob with play-dough or modeling clay will shut it up for good.

Alternative solutions include a grenedilla wood shift knob to match one's oboe. :wink:
Robbie

Mon Jun 29, 2020 6:05 am

Take a tiny glob of clear silicone and smear it around your shifter’s male threads and screw that knob back on and then don’t touch it for at least 24 hours. Your rattle will be gone and you will still be able to easy unscrew the knob I’d you have to. Consider painting your shifter lever first because paint won’t want to stick to silicone. If that’s a concern, use polysulfide sealant. Paint will stick to that. Both will stop that rattle

Mon Jun 29, 2020 7:50 am

airschooled wrote: Jeff, I'm surprised that you missed the resonator design on the underside of the shift knob. ;)

The cavernous space in the plastic mold under some shift knobs acts as an amplifier for any minute rattle. Anything from loose motor mounts, to an out of balance engine, to a bent shift coupler can cause vibration. The knob is only turning existing vibrations into sound.

Once you have ensured that all your shifter parts, bushings, and lubricants are in order, and you promise your shift rod and engine alignment are good, filling the space in the shift knob with play-dough or modeling clay will shut it up for good.

Alternative solutions include a grenedilla wood shift knob to match one's oboe. :wink:
Robbie

I think this is correct in my case. Because it is not as though the stick is not vibrating when I take the knob off. The knob is just not amplifying the sound when it is off.

So , yeah. I think round #2 is in order for a shift rod refresh.

Time to begin the research....

Mon Jun 29, 2020 5:56 pm

Quote: Jeff, I'm surprised that you missed the resonator design on the underside of the shift knob. Wink

Well - what can I say, my diagnostic chops are still in the apprentice stage.

After reading the comments about the shift lever knob and its resonance chambers, I removed mine and was shocked at its very minimal weight.

I still think the vibrations are coming from below. This same thing happens on my big bass fiddle - sometimes it will get a small (and irritating buzz) and I take it to my repair guy. Eventually he finds a small crack in the wood or a loose seam that may be two feet away from where the buzzing sound is coming from.

Vibrations can find paths that don’t seem logical or systematic as we try to track down the source.

Keep us posted on your next steps.

Jeff

Sat Jun 19, 2021 4:52 pm

Any thought on what just taping a weight to the shift lever would do? or alternately assuming the shift lever is solid steel, maybe finding a hollow one in the wrecking yard and welding it onto the stub of the OEM VW one?

Sat Jun 19, 2021 5:02 pm

it is a one year old post.

One source of rattles in the shifter are the steel doughnut that some folks use in the nosecone. The rattle transmits all the way forward. That is probably why VW used a fiberglass reinforced plastic ball. They are still out there if you can find them. You can see the threads of fiberglass or something like it in them.