I have a '66 Mercury S55 428 car that needs rear end work. I had the 428 built and installed a TCI C6. The rearend is one wheel peel and with the power in the motor I am spinning all the time. I need to identify the rearend so I can pick out some type of locker to install. I am a novice at Ford rearends and need some direction on how to identify what I have in the car. It is an original 428 car and I have heard that means it would have come with a 9".
I have heard that a Detroit Locker is the hot setup for a 9" so I have that in mind, but identifying the rearend, spline count, bearing size, etc are all a mystery to me. These are all things I am seeing as variables when looking at the different units available.
This is a street car, recreational driver with 410hp.
I have been asking for and receiving information from this and the FE forum for years as I built this car and I am finally driving down the road!
1966 Mercury and Ford 428 engine optioned cars [std on Lincoln] were built with 9-3/8" rears, 31 spline axles with a very large axle bearing [Lincoln] If nothing has been changed your car has a 2.80-3.00 or a 3.25 ratio. Depending on what was ordered when new. Because of the non Equa-Loc that you say I would guess at 2.80 or 3.00 ratio. 3.50 was available on request
Again check your tag on the rear 3.00 is 3.00 non Equa-loc 3L00 is Equa-Loc, 3L50 would be 3.50 Equa-Loc and so on.
The door code under axle will also tell you what the car was built with
You might have a Equa-Loc rear which has worn clutches. Which is likely because of the type of special interest car usually has more options.
The good thing is, a 9" center section with 31 spline will go right in.
Detroit Lockers are good for EXTREME use only. Very durable but to drive on the street will be a experiance you will not forget!
