9" - 12 bolt

[greenXpress]

Blew apart spiders last night and took out my ring gear too. Now wondering how much more hard earned money I want to keep throwing into this 12 bolt truck rear end. I am currently running Yukon c-clip axles and am looking at a GM locker, but will need to eventually go to c-clip eliminators if I keep trying to go fast pushing 4700 lbs. This means having to buy more axles or cutting these down. Have looked on Craig's list and there seems to be a bunch of 9" units out there, but the only thing I know about a 9" is that it might be 9inches.

I need info on what to look for in Ford 9", yes, I will consider the dark side for this. Questions I need answered are will all the parts interchange on the carriers? Can I put a spool in an open carrier? How tough are the oem limited slip units if I find one? Need to stick to a very tight budget and am counting on selling some of my 12 bolt stuff if I go this route.

Once again, counting on my DW buddies to get me on the straight and narrow ...........now that's really different. Preach away folks.

[squirrel]

You're probably better off getting something built to your specs, as trying to find a stock 9" rear that will fit and be strong is pretty much impossible. The centers interchange, there are different spline counts on the axles, and different pinion yokes....you probably want to start out with 31 or 35 splines, and a 1350 yoke. Stock limited slip units are weak, I suggest either a Truetrac or Detroit Locker diff. There are also different carrier bearing sizes, 3.06 is pretty common for 31 spline, 3.25 is the heavy duty setup.

Expect to spend money on it, but if you do it right you'll only spend the money once.

[Orange65]

My truck has a 12 bolt impala rear that has a spool, a steel cap, girdle, Moser axles, and 9" housing ends. The rear has also had the tubes welded into the housing. With all this done, I would say it is probably good to low 9 sec range if I brace it. I started down this road years ago and it is just cheaper to upgrade rather than replace it.

That being said, I would go with a 9". That saves you from buying c clip eliminators. Spool it and buy some Moser axles. As you can afford it, go to an aftermarket center section and pinion support. Depending on how quick you want to go, you may need to brace it too. Nitrous is going to load the rear up especially pushing 4700#.

If you decide to stay with a 12 bolt, you need to find a big car rear. Trucks have a smaller pinion diameter and are weaker. NHRA used to not allow truck rears to my memory.

[quick 52]

If your handy and can fabricate then put your bracket on a 9" housing isn't that bad.... you can google length of rear and find a rear the the will work... they also have off set housing the yoke will be offset to the pass side 4" mainly in older trucks this makes both axle the same length... its not a problem using one been running one for years... also there are different housing some are HD and some light duty try and stay with a truck housing bronco.. Ford uses a 2 pinion and 4 pinion posi both are weak a locker is best but loud there many aftermarket posi I use a truetrac been good but wish I would have used a locker... posi and locker come in 28,31,35 spolls come in 28,31,33,35 and larger... then there the third member or case, pig nodular case is hard to fine but under 550hp a stock case will hold up with a Daytona support... Some run the old war pigs I have with good luck some say their weak your call moser makes a 9+ good for 600hp for a couple hundred im using one hope this helps

[LAGNAF]

If you go with the9". Definitely get a good limited slip or locker!!

Last Friday I just destroyed my 2nd stock ford LS trying to back up my 11.87 pass!!!!!

[ProCharged509]

I suggest you keep the truck 12 bolt (that housing is stronger than car 12 bolts)
Verify the housing is straight, weld the tubes to the center section, drill out & re-weld the rosette welds & strap the spring perches.
Truetrac (about $430 at Summit)
Street Gears
Quality bearings
Aluminum rear cover (with the carrier cap preload bolts)
Synthetic gear lube (like Amsoil "Extreme Gear" 90wt)

...while you're got it apart, you might also consider...
1350 u-joint drive shaft & yokes (Spicer parts front & rear)
Big bearing c-clip eliminator kit for stock brakes (if housing is straight)
or... Big bearing weld-on housing ends for stock brakes (if housing straightening is needed)

[greenXpress]

I suggest you keep the truck 12 bolt (that housing is stronger than car 12 bolts)
Verify the housing is straight, weld the tubes to the center section, drill out & re-weld the rosette welds & strap the spring perches.
Truetrac (about $430 at Summit)
Street Gears
Quality bearings
Aluminum rear cover (with the carrier cap preload bolts)
Synthetic gear lube (like Amsoil "Extreme Gear" 90wt)

...while you're got it apart, you might also consider...
1350 u-joint drive shaft & yokes (Spicer parts front & rear)
Big bearing c-clip eliminator kit for stock brakes (if housing is straight)
or... Big bearing weld-on housing ends for stock brakes (if housing straightening is needed)

Tubes are welded, along with my homemade version of cal-tracs, 1350 already on, and have pre-load aluminum cover. Gear Motive ring & pinion with their installation kit (Timken)
Currently have a series 3 (3.43 LS) I carry as a spare, but my series 4 carrier puked out the spiders and by time I buy them, I'm close to a new unit.
I was hoping a stock 9" LS unit would be strong enough, but Dan's on his second in the 53 without spray. I found a complete unit (drum to drum with LS) out of a 79 Ford truck for $200 but will need to cut down left side and get new axles along with new ring & pinion.
looks like I have another winter project as soon as I decide.

[poison gas]

Watch ebay and "racingjunk.com" and you'll find what you need after you make your choice on which way to go. I troll both for my parts. Oh by the way, Mid 70's lincolns have a 9" thats almost the same width as your truck and is the heavy duty housing with the same bolt pattern.

[ProCharged509]

Tubes are welded, along with my homemade version of cal-tracs, 1350 already on, and have pre-load aluminum cover. Gear Motive ring & pinion with their installation kit (Timken)
Currently have a series 3 (3.43 LS) I carry as a spare, but my series 4 carrier puked out the spiders and by time I buy them, I'm close to a new unit.
I was hoping a stock 9" LS unit would be strong enough, but Dan's on his second in the 53 without spray. I found a complete unit (drum to drum with LS) out of a 79 Ford truck for $200 but will need to cut down left side and get new axles along with new ring & pinion.
looks like I have another winter project as soon as I decide.

With what you've already built, you only need a Truetrac or a Locker (you'd need aftermarket axles to run a spool).
The truck 12 bolt Truetrac I saw at Summit is for 3.73 and deeper (4 series).
If you go the 9" route, use a "big car" housing, nodular center section & pinion support (nodular or aluminum). I've see a bunch of non-nodular third member pinions puked right out on the starting line!

[CDMBill]

I'm a big fan of the newer aftermarket 9" pumpkins from Strange, Currie, Moser etc. A lot of goodness for the dollar. I run the Strange Pro-iron case which is overkill for you at the moment, but with the large bearing 9+ or similar and the big pinion support it'll hold up better than any 12 bolt you can buy for less money. Go 35 spline if the budget permits and there are Tru-trac units for 35 spline now. It will be more money than you might want to spend, but it'll live for years. Oh, and get the housing braced and straight.

[TheSilverBuick]

I'd have to dig up the bill, but the 9" and housing I got from Quick Performance with a tru-trac, 1350 yoke, and 31-spline axles (my decision to stay that low) was surprisingly cheap and had no issues with my request to have the axles drilled for both 5x5 and 4.75x5 bolt pattern with the studs installed in the 5x5 holes. Two other companies I called had issues with this and with selling an essentially ready to go package of carrier, case, housing and axles, but Quick Performance had no issues putting my order together and it showed up at my door step in half the time they quoted me.

[bulletproof]

id go 9'' tons of options.. cheap. and you can swap gears fast..

[BBO Javelin]

12 bolt is tough. I blew the spiders out on my moser 12 bolt a month before DW. I put a full spool in it and all is good. It's a stick car and I leave at 6,000.

[greenXpress]

12 bolt is tough. I blew the spiders out on my moser 12 bolt a month before DW. I put a full spool in it and all is good. It's a stick car and I leave at 6,000.

Need to finish paying off DW2013 before I can do anything, but was looking at a spool with both 12 bolt and 9" because of price. I am concerned how it will react on street. This is my daily driver. Not just during drag week, I am stuck in an old kia sportage until I get the truck fixed.
Do you drive on street during bad weather?

[Orange65]

Need to finish paying off DW2013 before I can do anything, but was looking at a spool with both 12 bolt and 9" because of price. I am concerned how it will react on street. This is my daily driver. Not just during drag week, I am stuck in an old kia sportage until I get the truck fixed.
Do you drive on street during bad weather?

My 12 bolt is spooled and I drove thru some rough rain on DW. I had some squirrelly moments but that was while I was on drag radials (and once with a ladder bar bolt working its way out). The driving I have done with a spool in the rear has been about the same as when it had locker. Rain or shine. It just makes turning at really slow speeds tough. Mixing rain and wide tires with little tread made mucho difference (BAD COMBO).

Do a little research on YB on street driving with a spool- I did last year before I got mine. I was a little concerned over some comments I read about some lockers locking and unlocking while racing. I can live with my spool- so far it is predictable.

Arrgghh- a KIA Sportage!