I was reading through Randy's R&P setup page and it says with tires over 34 you can easily break the pinion support or carrier caps. I suppose most people break them with 351s or bigger engines, not 4.0 I6s.....so have any of you broke anything. I searched and most stuff was only about broken shafts...o yeah i have 31 spline, 5.14s and a spool turning 37 MT/Rs. Thanks.

If you are really worried about it which I wouldn't be.

You can always get a nodular pinion support and center section.

I had a 9" in my YJ with 4.56's, full spool, 31 spline axles and 38.5" SX's Never hurt a thing. My buddy has the exact same setup but with 4.88's and its fine. This was with 4.0/automatics

9" is plenty strong

I'm running a 9" with 5.38's and a spool, 28 spline shafts and 35's, no breakage yet, but they do break and when they do, they do it big!

http://www.thunderbayoffroaders.rockcrawler.com/images/dune3.jpg http://www.thunderbayoffroaders.rockcrawler.com/images/dune4.jpg

That's under a 6000lb '78 Bronco with a built 429, runs mid 13 sec. 1/4 mile with 35's. It rammed the carrier through the caps, leaving a ring gear imprint on the outside of the housing, and threw the pinion completely out onto the ground. He did that twice within three months, he's looking at 60's now.

I've run a 31 spline 9",4:56, spool in a CJ 7 for a couple years with 36's with no problems. Have had 38.5's on for a couple months now so we'll see what happens.

31sp, 4.56s, 4.0I6, automatic, detroit. No worries. As far as that picture goes, I would guess that the bronco jumped and compressed the driveshaft when he landed which didn't have enough trave and hosed the 3rd member. I have never seen anything like that in the rockcrawling community.

SeanP

You're right on the jumping part, only about a foot of air, but we came down still on the trottle, so something had to give. The second time he did it was at the truck pull, he was well on his way to a full pull when he broke traction and started wheelhopping, loud bang, then it bounced off the rev limiter (8500rpm) and the speedo went to like 140mph, the front tires were smoking Cheech & Chong, driveshaft hoops save lives, can you imagine your driveshaft whipping around under the truck with a 20lb pinion and support at the end?

Stock centersections are know for cracking or breaking at the 3rd pinion bearing. This is not a problem with aftermarket nodular centersections. You need one of these to run 35 spline shafts anyway

my paychecks do not allow me to get 35 spline yet, but if i break shafts often then i will get a 3.250 case and the 35spline. I'll just go easy. Thanks guys, its always good to get some straight answers.:beer:

hey, i was wondering what year everyones 9" was and what it was out of. There is on in the paper, but it doesnt say what it is out of. It just says 9" NOD 4.56, locker, rebuilt. I have also heard that the NOD is weaker? this true? I still need to get off my ass and call about it.
thanks
nick :beer:

You can get a spacer to run a 31 spline detroit (or other??) in a 3.25 case. Perfect choice for future upgrade

Want a sweet axle? Try lincoln continental 78-79. They have the big bearing big bolt with disc brakes. 5 on 4.5 bolt pattern. Only 28 spline, but you can snag a third member from an F150/250 that has 31 spline carrier OR just get a detoit and ARB that are 31 spline and order some axles from dutchman (about $370 a pair with new bearings and studs). The lincon is a nice width for a jeep.

So:
Axle $150
Calipers $80 (you won't want 25 year old calipers)
Rotors $45
Dutchman $370
Perches/shockmounts $40
ARB$575
Gears/install kit $200

So for $1200 you get a sweet set up.

SeanP

36x12.50 SX's at the time, 4 cylinder, 9" with 5.14/detroit, 31 spline shafts and a KAPOW!
http://www.insayn.rockcrawler.com/images/9_inch_carnage.jpg

I'm about to buy a 9"...im going to run 33's and 35's on it with 4.56 gears and a detroit locker...i should be fine right? I knwo pussy tires

Will

Loaded question there. I am not sure how you wheel, but for me it has been fine. There is a newer release of the ARB for the 9" that works better than early releases. AS with any detroit, a broken axle will typically unload all torque to the other axle thru the detroit, trashing the inners of the detroit. Make sure that you get some alloy axles (moser, dutchman). Also, check out the summit catalog. For about $50 they sell the same brace that Currie used (uses?) that goes along the rear edge of the housing. This really will strengthen the axle tubes.

The 9" is a great axle. Most short wheel base guys stay away from the low pinion because of steep driveshaft angles, but for XJs (with longer wheelbase and driveline) I find them really solid. The are a hell of a lot lighter than a 60, you can get carriers for 35 even 40 spline axles.

Good luck

SeanP

SeanP- do u have any pics of ur XJ.

Im debatin on ARB or Detroit...and i wont be running any bigger than a 35" tire not a swamper either

Will

a buddy of mine has a 78/79 bronco with a ford 9" in it. we were in clayton a year or so ago and he snapped both bearing caps and destroyed it. he was running stock 400/C6/205 with 38's

Originally posted by whatdaphuk
I was reading through Randy's R&P setup page and it says with tires over 34 you can easily break the pinion support or carrier caps.

I think Randy's R&P is just trying to cover their butt for liability reasons.
One thing to remember about the stock 9" housing is it is made of plain Gray Cast Iron. And with any casting, flaws may be present.
Also Gray cast iron maxs out at 60,000 psi tensile strength where as Ductile(nodular) Cast Iron maxs out at 120,000 psi.

I think the 9" inch in stock form is plenty tough except for the situation that 4Bangler discribed with his buddies rig: High shock loading of the driveline:nuke: Gotta wonder if a D-60 would hold up very long with that kind of abuse.

Anyway, just my 2 cents.


Eric

you can see some more of my phots at

http://www.webphotos.com/list_albums.asp?mi=1&smi=1

SeanP

Here is what my banger did with 5.14's, a full spool and 36" PJ's....the 9 inch is out of an f150...

http://photos.yahoo.com/bc/biggreenjeep/vwp?.dir=/Jeep&.src=ph&.dnm=pinion+housing.jpg&.view=t&.done=http%3a//photos.yahoo.com/bc/biggreenjeep/lst%3f%26.dir=/Jeep%26.src=ph%26.view=t


http://photos.yahoo.com/bc/biggreenjeep/vwp?.dir=/Jeep&.src=ph&.dnm=drivers+side+2.jpg&.view=t&.done=http%3a//photos.yahoo.com/bc/biggreenjeep/lst%3f%26.dir=/Jeep%26.src=ph%26.view=t

[with 35's. It rammed the carrier through the caps, leaving a ring gear imprint on the outside of the housing, and threw the pinion completely out onto the ground. He did that twice within three months, he's looking at 60's now.

[/B][/QUOTE]

I did the exact same thing 10 miniutes after getting a fresh motor in. Go with a nodular housing and it won't happen.

Yeah, he's got two Nodular housings, one is missing the caps, the other has a broken one, and none of the other 9 million 9" third members he has have caps that will fit, I think some aftermarket supplier must make replacement caps, but he hasn't been working on the Bronco in a long time, too busy with his Jeep and new baby girl. I told him to run a 14bolt chevy and he kicked me out of his house.

"Here is what my banger did with 5.14's, a full spool and 36" PJ's....the 9 inch is out of an f150..." Those Parnelli Jones tires are awfully heavy, lots of rotating mass. My 9" is running 5.38's, full-spool with 35" MTR's, I really should pull my 28spline shafts out, I wouldn't be surprised it the splines have a little "shift"