stock ford 9 inch locker spine count.

does anyone know what the stock spline count was for factory 9in locker rearends? i heard there all 28 spline.

not 100% its been some time looking at stock stuff but i think 28,31 some one mite chime in to give you a 100% answer

I hope so. The 8.8 i was going to use turned out to be badly cracked in the axle tubing and warped on the otherside

some were 31 spline but that does NOT mean they are the same strength as aftermarket 31 spline stuff.

whatbumper wrote:some were 31 spline but that does NOT mean they are the same strength as aftermarket 31 spline stuff.

yea i figured as much. im back to poking around for rears and i figured why not just stuff a 9in in and be done with it. plan on swapping axles and the 3rd member housing and gears regardless on what i find.

You can get some really good stuff here.

http://www.quickperformance.com/

The factory Ford ones were 31 spline.

What did Ford put a factory locker in? As far as posi and normal diffs most cars were 28 spline and the trucks were 31 spline.

lockers were installed in 71 boss and 429 scj mustangs

"Factory" 9" Detroit Lockers were available in both 28 & 31 spline. If you want a 35 spline 9" Detroit Locker (using the "Dana 60" 35 spline 30* pressure angle profile) your only choice is the aftermarket like Mark Williams, Moser, etc, etc.

Maddmattmustangs wrote:lockers were installed in 71 boss and 429 scj mustangs

and 68-70 cj, scj 428

all 9" rears were 28 splined but the 302 Boss, 351 Boss, 429 Boss, 428 CJ and SCJ, and the 427 Cars and they were 31 splined...... and some of the pickups are 31 splined also... but I have found no significant reasoning in which ones were and were not.....



Randy

thanks for the reply guys. Found a 71 mach 1 locally that a friend of mines father owns. going to go check it out and see if its got a 9 in.

Coug, Im assuming that the heavier 3/4 ton trucks are probably the ones with the 31 spline?

Maddmattmustangs wrote:thanks for the reply guys. Found a 71 mach 1 locally that a friend of mines father owns. going to go check it out and see if its got a 9 in.

Coug, Im assuming that the heavier 3/4 ton trucks are probably the ones with the 31 spline?

the only trucks with 9" rears were 1/2 ton. you can find then well into the 80's. bronco's only had 28 spline axles for most of the 60's and 70's but could be both in the later build dates but like Coug said in the trucks there really is no rhyme or reason to application.

if you're concerned about big bearing housings or small bearing housings you can look at the backing plate retaining nuts for an easy reference. the big bearing housing had 1/2" bolts and small bearing housings had 3/8" bolts.

a little more fyi

whatbumper wrote:

Maddmattmustangs wrote:thanks for the reply guys. Found a 71 mach 1 locally that a friend of mines father owns. going to go check it out and see if its got a 9 in.

Coug, Im assuming that the heavier 3/4 ton trucks are probably the ones with the 31 spline?

the only trucks with 9" rears were 1/2 ton. you can find then well into the 80's. bronco's only had 28 spline axles for most of the 60's and 70's but could be both in the later build dates but like Coug said in the trucks there really is no rhyme or reason to application.

if you're concerned about big bearing housings or small bearing housings you can look at the lug nuts for an easy reference. the big bearing housing had half inch studs and small bearing housings had 3/8 studs.

a little more fyi

thanks. I want to try and find a big bearing housing to install on the car.