9" rear end only handles 450hp? How do I swap gears and what fluid to use ?

X1Lightning · 07-25-2002

I just picked up a 1959 ford 9inch 28 spline rear end came out of some big car. now they guy that sold it to me tells me it can only handle 450hp is this true? i thought the ford 9" could handle alot more than that????
Plus a got a second carige with it that has a locker but gears on it are 2.79.. now the gears in the rear end are 3.10 will i be able to just swap the gears off the open diff with he locker??? and do i need to buy any specail fluid for a locker? and i see in summit that they say you have to buy some kit when you get new gears what is that all about??? is there anything crazy i need to know about before i swap the in the locker?

BISKIT · 07-26-2002

you may want to find a 31 spline,how much hp do you plan on running?
yes you can swapp in a locker and gears in your case, summit has a
detroit for around $400 and no you wont have to run any friction modifer fluid with a locker, they are gear operated, if it were a auburn
style that has clutch packs, that is when you need the fluid..

X1Lightning · 07-26-2002

well my hopes are 500hp but realisticly 430hp to 450hp at crank... will this rearend be enough? or will i end up blowing my rearend?
will ineed anything special when i put the open gears on the locker ??? or just a gasket and fluid?

Groove · 07-26-2002

here a site that might help you http://www.ultrastang.com/Rearinfo.asp?Page_ID=1

BISKIT · 07-26-2002

Gears are Gears. You will need to know if you have the large or small bearing case, once you figure that, get a install kit from Richmond. It will have all your bearings except for your axle bearings, and also comes with shim kit, presson blue, gaskets etc. to set it up

Are you going to use your old gears? If it were me I would can those and get some 3:25 or even some 3:50's

As for oil it would'nt hurt to put in some 75W140 synthetic gear oil to protect your investment but thats just my .02 worth.

JEFF

X1Lightning · 07-26-2002

so you get bearings in that kit??? thats why it costs so damn much i couldnt understand why gaskets would cost so much. I was planing on down the road getting 3.50 gears.. but maybe you are right and i should just do it from the start so i dont have to mess with it later. right now i have 2.79 in the 8inch i'm runing and the car is pretty quick.. this thing would be lightning quick with 3.50 gears in the Locker 9"...
thanks for the input

JRD · 09-07-2002

The lower ratio gears will swap with no problem, just be sure they are still in good shape. Use regular rear gear oil for your locker. My only concern as far as strength is the 28 spline axels. Go to 31 spline axels and you won't need to worry with the HP you now have. If you want to sell those 2.73's let me know.

X1Lightning · 09-08-2002

you can just swap out 28 axels with 31's ? what all has to be changed when you do this and where do you get 31 spline axels from?

blown65 · 09-16-2002

you cant just replace the axles without replacing the locker, limited slip or whatever you may have differential. I would agree though that 28 spline axles at most would handle 450hp. IMO they prob arent even that strong, I already have started to twist one with my old engine setup and it was right around 400hp on an auto tranny. If your a stick you will shock the axles worse than with an auto.

JUSTNLX · 09-16-2002

You can give Kent Anderson a call at Currie too. They have been building 8" and 9" for some time now. I bought a housing, axles, case and pinion support that will handle over 700 hp @ the wheels

http://www.currieenterprises.com