Thread: 9" Ford Rear Center Section - 31 Spline

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Thanks, guys. Looks like they won't be hard to find.

This is probably more rant than rave.
I got a complete 9" as part of a rod parts package. It had some big drum brakes on it and was very oily and full of dirt. a mess. It had 31 splines ok, open carrier.
First was taking it apart. Every bolt and nut was rusted tight. I had to heat every one of the carrier nuts to get them off and all 8 of the backing plate nuts/bolts. You would not believe what this thing smelled like.
Next both axel bearing were totally worn. A 40 ton press wouldn't even budge them so I had to cut them off. The housing bearing rings popped out with a good puller.
The pinion nut took a special bolt-on bar and my big truck lug nut cross to bust loose. Then it took another puller to get the bearings out. These were also fully spalled. It must have made a big howl going down the road. then the carrier bearing races had to be cut off and they were galled up. What a mess. I didn't plan on reusing any of them but this thing had to have the crap beat out of it.

Then I find out it has the small carrier bearings typical of a 28 spline and the 31 spline spider gears. These are not availabe for this combination anymore so I'm told. Just great and orphan. At least it had the new style housing ends.

Then I go over to the car wash to clean it up. haha I'm right in the middle of engine cleaning it and who shows up?? The owner. Well he runs me out of there on a rail. Says that the inspectors don't want grease and oil in the drains. I asked him what he has engine cleaner for then. Well I got the boot anyway.

Off to the sand blaster. The going rate was $50-70 but I managed to get it done with some other stuff for $30.

Now back home I get ready to narrow the thing and behold it's a truck rear end with the 3 1/4 " tubes tapered to 3" right at the end. Well with some carefull measurement I was able to make the cuts right on the taper and weld it back together. I have a pretty stout line up bar and pucks so even if it is a bit out of line with the housing after welding the bearing housing are in perfect alignment.

But now my nicely made 4 link plates don't fit the tubes so I have to cut the plates for the 3 1/4 tubes. the disc brake brackets also had to be reworked. PIA again.

About the only thing that went well was setting up the new ring and pinion. BTW I used the pinion spacer and shims instead of the crush sleeve. Great item.

Not done yet. I tried to put the axel bearings on but they were locked up tight. took them to the drive line shop and they busted one with a 50 ton press. Turns out the bearing is China made and undersize a little. So another $65 for new bearings and these also are on the small side and the axels are on the very larger side. We had to grind down the axel a few thousandths to fit. PIA. So homeward we go. Only to have buddy mess up one of the axel seals. Dang. I need to lose this thing before it drives me crazier than I am.

As it turns out up untill recetly there was a ball bearing that exactly fit instead of the tapered rollers. No such luck now they don't make them anymore. These really made the seal problem go away.

Anyway the bottom line is avoid the truck stuff if you are narrowing it. Actually looking at what these go for now in the junk yards you can build one out of brand new stuff for a net of less and have mor fun doing it..

Edited today:
Well another thing. I just got the long awaited rear disc brake set. More truck rear end troubles. Dang when is it going to stop. Now the blasted axel flanges are too big to fit inside the rotor hats. Like by about 1/2 inch or better on diameter. Well the axels go off to the machine shop tomorrow at 0700. Looks like another $75
I learned something about this thing, Give me a Dana any day. Otherwise just order new parts no more junk yard stuff. They are getting way past $200 for these things now. If they have one.