Early Falcon rear end

[junker39]

I've been given an early v-8 Falcon rear. It's a five lug. I'm guessing this would be a healthier rear for my project than the 80s Courier. Are gear sets still available and what would the technical term be for this? An 8", or what? I am clueless on rear ends. Thanks.(I can get a pic when the weather straightens out.)

 

[donsrods]

Most likely you have an 8 inch rear there. Those were commonly used in Mustangs, Rancheros, Falcons, etc. Nothing wrong with them at all, I am using one in my rpu project. While everyone talks about a 9 inch rear, an 8 inch one can have some benefits like less unsprung weight, and you really only need a 9 if you are going to abuse it a lot.

To determine if that is what you have, the center section comes out of the front with something like 10 nuts around the front side of the housing. If it is an 8 incher you can get a socket on the two bottom nuts to remove them, but if you need a combination wrench to get on there it is a 9 incher, but those were not commonly used in lighter cars like the one you have.

As for gear ratios, there might be a metal tag on one of the 10 studs, but if it is missing you can either count the teeth on the ring and divide by the teeth on the pinion (after you remove the center section), or the ratio will be stamped on the back side of the ring gear. You can also roll the car and count the number of revolutions the tire makes compared to the driveshaft.

Here is some info for you:

http://kevinstang.com/Ninecase.htm

Don

 

[junker39]

Thanks Don. Now all to do is decide whether to pull the Courier rear out now or wait for it to break on me. I guess I can save a headache and some driveshaft money by doing it now before I get the shaft finished for the Courier. Oh boy. There's another six months at my rate of progress. Thanks again.

 

[donsrods]

You're welcome. It all depends on how much you plan on abusing the rear and how sticky your rear tires are. I'm running a 9 inch in my 27 but with only 28 spline axles. I should have 31 splines because I do abuse it and I have a fair amount of hp in the motor, but my tires are skinny, so they spin before anything breaks.

But you might be better off to just get it out of the way and make the change now........so much easier to do it before the car is done.

Don

 

[junker39]

I finally made it out to pick up the rear and sadly discovered it is beyond the use stage. Pulled it up out of the dirt and the rust flakes were about a quarter inch thick. I chipped on it a bit and the metal on the housing bent after the big flakes were gone. Nothing left. And the brake backing plates are barely even there. It will be going to the recycle bin. I guess twenty-thirty years of sitting in the dirt was just too much. I'll keep on looking.