OK, so I replaced my shifter and coupler bushings, and now I hear a vibration

[911SCRVA]

First of all, thank you to those who helped me out the other week with their tips, kindness and wisdom.

I easily replaced the shifter bushings, then moved onto the coupler bushings.





It took a little fine-tuning to re-find the 1st/2nd shift plane, but I did it (thank you John Walker's Workshop for the winning suggestion).

Next, I test-drove it to see if I nicked R when downshifting from 5th to 4th. No nicking.

But now there's a little buzz or vibration and 2nd, 3rd and 4th gears. I can't tell if it's coming from the shift box area or the coupler box area, but it's new. Any suggestions of what it might be? And how to eliminate it?

*Also, I can't reseat my shift knob all the way back down--I didn't replace the old crush ring because it looks totally fine, but am wondering if that's why the knob won't go down all the way.

Thanks in advance for any help!

[Locker537]

Double check every fastener you touched is tight.

A loose fastener can create some significant noise. Start with the easy stuff.

[gsxrken]

The brass bushings will transfer more noise and vibration than the nylon ones did.

[cabmandone]

Originally Posted by gsxrken

The brass bushings will transfer more noise and vibration than the nylon ones did.

^^^
Yep... I found that to be the case when I put the brass bushings in my car.

[jac1976]

Originally Posted by gsxrken

The brass bushings will transfer more noise and vibration than the nylon ones did.

Came here to say this. Whatever you are hearing/feeling now was likely there before.

[MichaelSJackson]

I got a lot more transmission noise when I replaced my bushing with one of the aftermarket couplers. Not the coupler's fault, I was just hearing the wear in my transmission. Quiets down if I put in the clutch and coast at speed. While I need to have it fixed, near term, I've replaced the bushing (delrin) in the original coupler to quiet the whine.

Your vibration could be lots of things. Test to see if it quiets down while coasting?

[Danimal16]

What kind of motor and trans mounts are you running?

[pmax]

I believe a primary reason for the rubber bushings is to reduce NVH , given our cars are meant for the streets as well.

[Jonny042]

The factory bushings have oval holes to allow a bit of fore/aft isolation - the coupler is designed such that they can only be clocked one way, and will not rotate.

A fresh set will probably cure the vibration.

[Jgordon]

What kind of car do you have? there was a factory fix for buzzy G-50s that basically cinched up the linkages with large rubber O-rings. I used zip ties a few years ago and haven't ahd an issue since.

New shifter slop? Bushings gone?

[Deschodt]

I was just asking if there should be any slop in there, and I see this post... Wow, yeah, zero slop in those metal bushings... In my experience without the rubber you get more vibrations... I had the same problem when I went solid mounts for a tranny mount vs old rubber...

[Mike Andrew]

Had bronze bushings for years(Charlie Stylianos ?) and I have had a rattle/ vibe ever since. As noted above, the nylon bushings dampen these vibrations. Gotten used to it as normal over the years.

[911SauCy]

I experienced the same... New bushings, tight shifting feel, new rattle.

Nature of the best

[PorterF]

When I added the [Karsten] shift improvement spring, there was a significant drop in shift lever vibration. I have poly linkage bushings and factory cabrio motor/trans mounts.

Adding the spring might eliminate your vibration with the added bonus of improved shifting.

[Tremelune]

If you find it's definitely the bushings, and you want to replace them, these are well-liked:

https://www.early911sregistry.org/forums/showthread.php?154208-FS-911-Shift-Coupler-Bushing-911-424-223-03&p=1066363&viewfull=1#post1066363

JimmyT is a class-act. Send him a message.

[proporsche]

as treme ..said get rid of the brass and replace it with soft bushings..it was designed that way.Any plastic or other stuff will transfer all the trans noise to the cockpit...plus the stuff you put on does not look that it has any free space too tight...

Ivan