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Thanks to all the information here, I rebuilt the shifter on my FD and NA Miata same day as they are setup the same.
Reading about how quickly they deteriorate, I sought out a way to insulate the boot from the heat along the transmission tunnel. Essentially, the rubber shift boot is at the mercy of the constant heat generated through the transmission tunnel and from the outside elements.
I started going down the thought of heat insulation for furnace and fire ovens!
Only time will tell if this works or not.
Supplies for insulation:
1. Circular aluminum pie pans, got an extra one in case I messed up the initial slicing
2. Ceramic fiber insulation 1/8 in thick, purchase from eBay. See picture below of supplier.
3. Honda shin-etsu Grease
4. Utility knife
5. Sharp utility scissors to cut ceramic fiber
6. Scotch Super 33+ electrical tape from Home Depot
Steps:
1. After rebuilding the shifter and tightening down the lower rubber shift boot, I applied generous amount of shin-etsu Grease to the outside of the rubber boot, to moisturize the rubber and provide protection from drying up.
Applied shin-etsu grease to the outside of the lower rubber shift boot, inside and outside of the upper shift boot. This is a picture I took when I did the Miata.
2. Cut out the aluminum pie pan to cover the large gap between the turret and transmission tunnel. Shaped aluminum pie pan to fit around turret and fell gap between tread and surrounding transmission tunnel, secured in place with Scotch super 33 plus electrical tape that can withstand the heat generated in that area
3. Shaped 2 layers of ceramic fiber to fit over top of the aluminum. The bottom was trimmed in such a way that it approximated the outer edges of the rubber shift boot near the base leaving minimal gap and actually some overlay on top of the 10mm bolts (ceramic fiber is thick enough that it will hold shape, and fiber layers can still conform to irregular surfaces filling in air gaps. A second layer was placed on top with a more snug fit around the shaft of the shifter, to prevent the upper shift boot from being exposed to any residual heat.
4. Cutouts are positioned in such a way that the anchoring screws at the corners of the upper shift boot would be able to go down directly to metal, in hopes of preventing screw loosening over the years. Could consider using blue loctite if desired, but I did not do this myself.
Everything fitting back into place nicely, without adding much bulk
Hope this helps prolong the life of our rubber shift boots! If I can remember, I'll report back in about 3 years regarding the condition of the boots with this method of insulation.
Last edited by mazdas4life; Jun 13, 2020 at 04:08 AM.
If you read this far, I would appreciate some help regarding a blue connector I can't find a home for on the center console cover or anywhere else along the transmission tunnel. Please see my other thread that was posted just before this one. Thanks!
Re: the shifter boot...I did something roughly similar using closed cell underlayment I had sitting around (the kind they used under laminate flooring). I then laminated a double layer of foil on both sides using clear silicone and cut it to fit like a big gasket. It’s been in for 10 or 12 years now and going strong.
Re: the blue plug...the only thing I can think of is that maybe your car had the BOSE system at one time.
Great to hear your setup has held up that long, Sgt!
I chose ceramic fiber given its properties that I pasted below from a website for others to read. Also, it was easy to shape since it's like cutting thick foam or blanket, with a decent pair of scissors. Your idea sounds more robust, but only time will tell how mine holds up. I plan to keep my 7 for a long time - unless shifter gets crunchy in the future, I don't plan to open it up again
Unbelievable how much more fun to drive the 7 after the shifter rebuild! Should have done it sooner.
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Ceramic Fiber is produced from high purity aluminosilicate material through strictly controlled high temperature furnace melting and fiberizing process. The fiber is white and odorless, suitable for high temperature applications up to 2300°F. Commonly used Ceramic Fiber products include cloth, tape, rope, braid, tubing, paper, blanket, etc.
Main Characteristics and Specs
Lightweight, low thermal conductivity, high temperature stability, excellent handling strength, low heat storage, thermal shock resistant, fire and flame proof, chemical resistant, compatible with most corrosive chemicals, commonly used acid and alkali (exceptions are hydrofluoric, phosphoric acids and concentrated alkalis).
Chemical Composition: Al2O3 + SiO2 >97% ( Al2O3 47%); Fe2O3< 1%
Fiber Diameter: 3 – 4.5 microns
Fiber Shrinkage (1800°F, 3h): < 3.5%
Working Temperature : 1,800 °F. for Continuous Use, 2300 °F Maximum
Specific Heat (@2000°F): 0.27 Btu/lb °F
pH Range: 2-12
Typical Applications
High temperature insulation seals and gaskets
Protective blankets, curtains, covers, pads and wrapping
Of course it also helps to reduce the source of the heat and get the downpipe wrapped along with the inlet and outlet of the cat. You can also remove the dp and have it heat-coated. If wrapped, I recommend the DEI ceramic sealant on the wrap.
Thermal Insulation Purchase Source
