RFP

There has been a bit of interest lately on the wimpy and prone-to-failure factory rubber bushings that are used in mounting of the MN6 shifter box to the center tunnel. There has been considerable evidence that the rubber bushings deform and tear exactly where they should not: at the point where they absorb the forward and rearward pressure on the shifter box.

Upon removing my center console (for the zillionth time!) and removing my shifter box, I found that indeed my OEM rubber bushings where already well along the deterioration path... and that with less than 12,000miles on the odo!

One of my local friends (and Forum member) had already been working on a permanent fix for this little matter, so I was fortunate enough to have an excellent resource to effect a permanent "fix."

So, here's the short story... The fix consists of nine pieces... eight of the pieces go where the factory bushings once were (four pieces in each of the two mounting flanges), and the other piece is a "V-shaped" thingie that goes under the shifter box (replacing the rubber factory "V" which - as best we can tell - does precious close to nothing to secure the shift box. He has some photos of the parts and the installation... perhaps he will "loan" the photos to me, so I can post 'em up here.

I actually helped make the masters for the mold (can you believe that?). He has made molds and is casting the various pieces probably as I type away.

I already had a MGW shifter and full synthetic in the transmission... but when we installed these cast urethane parts, my shifter became simply excellent. This is a great upgrade... and pretty easy, too!

All the best!

Rb

07MontRedcp

Sounds great!. Can't wait to see the photos.

BJK

AORoads

good write up Rob. Maybe if your friend loans you the pics, you can do a tutorial on how it all goes together.

Eric D

Could you share this "consdierable evidence" source?

How many miles does your friend have on this forever fix? How do you know it will better or that it will not cause other issues?

My point here isn’t to poo-poo your friends Idea, but it seems a little premature to be making claims before a test bed of parts have been made.

Mez

That maybe fine for sometime in the future at an undisclosed cost, but for anyone that needs OEM type replacement rubber bushings NOW send me a PM.

I started a long thread a while ago on finding replacement rubber bushings and fixing the root cause for the factory bushing to fail so early.

I have done a lot of research and put together a kit. Included in my kit are 4 new high quality SBR rubber bushings (2 are spares), a standoff installation tool, and most importantly step by step instructions with high quality photos of the minor mod needed to the shifter box to eliminate the reason why the factory bushings fail in the first place.

Some guys may like the urethane bushings but they are much harder material so more vibration will be transmitted into the shifter than rubber.

Send me a PM for details and price.

Dirk Miller

I am interested
Dirk Miller

RFP

Another thread has covered this pretty well. Further, if you have a MN6-equipped car, odds are that you have your very own "evidence" right at hand,


While I have certain insight to the work that my friend has done, I'll not presume to speak for him... This is his design and the idea - as well as the work to turn the idea into actual parts - is his. I'm sure that he will chime in here soon enough; or, better yet, start his own thread describing his work and his results.

This is, of course, the beauty of urethane parts... they can be cast with virtually any durometer one wishes the parts to have. Want "stock like feel?" Simply cast a suitable (softer) material. Want "super-firm?" (that's what I have, and it's perfect for me... and no rattles!)... Simply cast a suitable material.

Rb

mitchydkid

In the spirit of sharing, here is my solution.

Installed MGW this weekend and made some urethane bushings just in case my stock bushings where trashed. Turns out the stock bushings where ok, but I put the urethane ones in because I had gone to the trouble and expense of making them. I figured they will last a long time.

Step one, buy aluminum solid bushings off of fleabay.
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Step two, make a mold.
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Step three, cast in urethane.
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I then installed as per the instructions on the B&M web site. So far I have had no vibration or rattle under any and all accleration rates. I have done a couple of WOT runs and was surprised to have no rattle. Of course this is just ONE car, so if you chose to do this to your car please do not blame me if it does not work out as well for you. Hope this is helpful to someone. As a side note, I did spend about $100 on this solution so I see why others are trying to recoup the costs. I was going to look into selling these since I already have the mold and lots of extra urethane, but I don't want to step on toes and prolly can't afford to become a vendor.

Sure do like the shifter!!! Good luck to everyone.

RFP

Dale...

Thanks for posting and helping to raise the collective knowledge and experience base for this little "bushing quest"... good photos, too!

If you don't mind, would you please help me understand something regarding the B&M short shifter bushings (that you replicated in urethane).

From the photo(s), it appears that these would cause the shift box to sit "taller" (relative to the tunnel mounting surfaces) than the stock bushings (whether the solid ZO6 mounts or the non-ZO6 rubber bushings).

Is that correct?

Since you have parts in hand (well, I'm assuming you do!), I'm hoping that you can tell me if the B&M bushings allow the shift box to mount at the same height (relative to the tunnel mounting surfaces) as stock.

Thanks!

Rb

Luweegy

Does anybody have the answer for the solid mount Z06 shifter box?

mitchydkid

Rob,
Since I do not have time to take the car apart the best I can do is measure the old rubber bushing and the B&M type bushing and compare. I did make an extra set because I wanted to marvel at my first venture into molding things. I did not think to compare thicknesses during installation. Anyway, from my memory I think they are pretty darn close to the same thickness.

Now what I do remember is that the steel sleeve that I took out of the stock bushing and put into the urethane bushing was pretty much the same depth as the urethane/B&M bushing. So, if the bushing where any shorter it would just rattle around instead of bearing any load.

mitchydkid

Ok Rob,
Here goes.

I lined up the "necked down" parts as those are the areas that pass through the box mount holes. It appears you are correct that the B&M clones are taller than the stock bushings. This brings up some questions I guess. Why would B&M do this? Are the stock bushings in this photo shorter than they where when new? Does using taller bushings have any long term side affects. I can't see it having side affects because the thing shifts so good and all, but who knows.

So my conclusion is that the B&M bushings raise the shifter box approximately 1/8th inch.

-Dale

Mez

You are not lining them up right. The shoulder of the urethane part slips all the way into the shifter box hole. Its too low in the photo.

Also, did you factor into your bushing mold for the fact the urethane bushing need to be slightly bigger in some dimensions and smaller in others. It needs to be compressed upon assembled or it will won't work right.

tomc8at

Yeah I need to find a fix...

mitchydkid

I see, yes, they are lined up wrong. If they were lined up correctly it would show that they mount the box at the same height.

LOL, no, I don't have your extensive knowlege in urethane bushing design so I did not adjust the dimensions, but the fact is my shifter is silent. Even without enlarging the bushings they are under compression.

-Dale

mittens

so how do you know if i need to look for this, car has a MGW shifter.

Mez

I doubt it....

RFP

OK, Mez... help me understand how Dale has lined the bushings up incorrectly. With respect, I still submit that the B&M bushings alter the installed height of the shifter box. Maybe you can use my crummy drawing (which I scribbled onto Dale's photo) to show me where I am missing the boat on this.

Thanks!

Rb

RFP

Just be patient... There are really some good guys working on this (and, "no," I'm not one of them... I'm more of an "early adopter")!

Mez

I urge everyone to look closely at the factory rubber bushings posted on this forum. In the photos you posted, I can see the bushing has been cut. What is causing this? Its the shifter box hole and the flashing left after the casting process. If the factory had removed the sharp flashing, the bushings would last.

Below - Here is a photo clearing showing the factory rubber bushing was cut by the flashing which eventually caused it to tear apart.



Here are photos of the installed solid B&M Bushing and the replacement bushings you can get today from me.


Below - B&M Solid bushing bottom view:



Below - B&M Solid bushing top view. Note the standoff is now is in contact with the shifter box. The shifter box is about 1/8 inch higher than original:



Below - My rubber replacement bushing top view. Shifter box sits about the same height as the original:



My rubber replacement bushing from the bottom:


Below - Here is what the rubber bushing will look like once installed with the OEM stand-off.