2 replies to this topic

[mbican]

Car started vibration over last race weekend,felt like previous ppf adjustment. Replaced diff last summer was properly torqued.Want to check it but floor supports are all smashed. Seem to remember something about shifter housing being a 1/4 inch above tunnel, can't find where I saw that,does that sound familiar to anyone?

[Bench Racer]

I sold my 1990 Spec Miata a few weeks ago and couldn't measure and I don't remember the happy number from shifter housing above the tunnel. Here is some information to support your checking process. Scroll to 3: Engine & Clutch pages 3:46 (dimensions, lower right hand corner) & 3:47 (dimensional sketch) and you'll find the numbers from the underside of the chassis. 

 

https://books.google...earance&f=false

[SaulSpeedwell]

From memory, the spec is in the FSM for NA8s, and the middle of the spec is 2.6" as measured from a straight edge across the bottom of the "frame rails", to the bottom edge of the PPF.  You can get it right by "feel", as the transmission will not be flexing the PPF downward with its weight, nor should you need to flex the PPF upward with your arm strength.  In other words, support the weight "neutrally", torque it down, and everything will generally fall into its proper place.