9 1/4 info please

[YY1]

Anyone got pics of their 9 1/4 axles?

I don't remember ever seeing a factory 71-74 B body unit.

I just bought a Dakota 9 1/4 3.92 SG and was curious about the differences besides the obvious spring perch. Right away, I see that one side is longer by quite a bit. Wonder if that will keep me from using it in my 74.

I measured the perches and backing plates, but my notepad is not with me right now. I'll post them when I get them back.

 

[SureGrip]

Anyone got pics of their 9 1/4 axles?

I don't remember ever seeing a factory 71-74 B body unit.

I just bought a Dakota 9 1/4 3.92 SG and was curious about the differences besides the obvious spring perch. Right away, I see that one side is longer by quite a bit. Wonder if that will keep me from using it in my 74.

I measured the perches and backing plates, but my notepad is not with me right now. I'll post them when I get them back.

The car I have now, a '72 SSP has one put in it. My Brother had a '73 and also put one in it out of a cop car. They came from Cordobas and such...

Here, I took this from the other thread on the first page:

I haven't gotten any info off of it to find out exactly what one it is though.

 

[jimbob101]

'74 9 1/4" rear

Here's a pic or two from my '74 satellite, I literally discovered tonite that there was a 9 1/4" in there, and didn't think they were in these cars yet. Just assumed it was a 8 1/4" What was the gear that they started with in the 9 1/4" rear? 3.23? Maybe '74 was the first year of this axle?

-Jim

 

[YY1]

Thanks. I'll get some pics of mine up. One of the things I'm trying to find out, is if I can put your type of axle shafts in, in order to go to 5 lug.

I've seen that chart before. It's not entirely correct (esp 62-70 8 3/4), and there's a better one out there, but it's harder to find.

Potential project #1 is put 9 1/4 in 74 charger after converting to 5 lug.

Potential project #2 is put SG unit in another 9 1/4 I have, with 3.55 gears in order to get better mileage in Dakota.

Might do rear disks from Jeep on either, while I'm at it. maybe Jeep shafts would get me 5 lug at same time.

Also got Cal-Trac setup with it. Just priced a new one at $370!

Paid $100 for all.

SCORE!!

JimBob, are your axle housing sides equal length?

I think I measured 26" on one side and 35" ?! on the other, but can't remember if I used the pinion center or ring "bump" as my center.

 

[jimbob101]

axle width

WHy not just get a 9 1/4" rear out of a mid late 70s power wagon pickup? THere's your 9 1/4" and your 5bolt axle shaft.. Or is a dakota rear narrower or something I don't know about?

Axle tube housing are about 19 1/2" each side, pinion offset on passenger side, measured from backing plate to start of differential.

-J

 

[rog_allen]

i NEVER KNEW OF A 9 1/4 I ALWAYS THOUGHT IF THEY WERE REAR LOADERS ( OR IF THEY HAD A COVER ON THE BACK ) THEY WERE 8 1/4.. IS THERE A EASY WAY TO TELL JUST BY LOOKING AT THEM ? i HAVE A PARTS CAR , ROADRUNNER 1974 BIG BLOCK 4 SPEED CAR WITH A REAR SWAY BAR THOUGHT IT WAS WEIRD THEY WOULD PUT A SMALL 8 1/4 IN THERE, MYBE I MIGHT GET LUCKY TOO,,,
THANKS ROGER

 

[YY1]

Thanks for the measurements. I didn't get a chance to doublecheck mine last night...

It was $100 for a 3.92 SureGrip (and Cal-Tracs). I haven't seen a 70's power wagon in any of the yards around here in over a year, and my brother's been actively looking for a hood for his Warlock. There've been some 80's and a 70's HEAVY, but I'm pretty sure they have much wider axles. Aren't they 5 on 5 lug spacing?

rog- look at the pic above- 9 1/4 has a "stop sign" shape.
There's a chart on here somewhere that has simplified shapes...

 

[Cranky]

Sounds to me like your 9 1/4 came out of a Durango and not a Dakota. IIRC, the only Dakotas that came with the 9 1/4 were RT's and should have more of equal length axles....Durango's had a longer axle on the passenger side by about 2 3/8".....iirc. What year Dakota is this unit supposed to be from? In 92, I bought a new 5.2 Dakota with limited slip and 3.92 gears but it came with the 8 1/4 but my 2000 Durango with the 5.2 and 3.92's has the 9 1/4 and it's longer on the passenger side.

 

[YY1]

This was a strange little truck. 1998 Sport-black short cab/short bed, 5.2, 5 speed. It had wheel well flares (gone) and R/T wheels (2 gone, I bought the other 2), and the axle. It also had a factory "dealer authorized PCM reprogram" sticker under the hood. that looked like handwriting on a touch screen, then printed- with the code version and date.

My bud, (who is a chrysler dealership parts guy), and I are speculating that someone may have put some salvaged R/T parts on it, and then had a dealership reprogram the computer for the new axle ratio. Aren't Durango's 5 lug?

Bet it was a fun truck to drive. I can certainly see the desireability of the Cal-Tracs.

The U-Pull people said it came to them as a mechanic's lein for a bad pressure plate, and that a brand new one was in a box inside. I can see the pressue plate issue, too.

 

[YY1]

OK, here's a pic.

It measures 57 at the backing plates and 43 at the perches, so according to the chart, it's real close to 66-70 perch and 71-74 backing plate. Hmmm.

Drivers side measures 31 from backing plate to pinion center, but pass side measures 26ish. Double Hmmm.

Directly in front of it is my next most recent score- a vintage Gray brand air assist hydraulic bumper/frame jack. It needs cleaned up and painted, but works. It was also $100.

BTW I measured an unmolested 66 8 3/4 and it is 52 to the backing plates +-, but NOT 55.

 

[Cranky]

Don't know about the newer Durangos but the early ones are 6 lug. They came out in 98 and our 2000 is 6 and a relative has a 2001 and it has 6 also...

 

[YY1]

Guess we'l just have to mount it up and see.

I notice it has "sway bar" mounts.

Thanks for eveyon'e info.

Anyone know if you need a case spreader to get the ring gear out, or if the SG will come out without removing the ring?

I understand these have crush sleeves for the pinion, but I think there is an eliminator kit.

 

[Cranky]

Our 2000 Durango has a rear sway bar. I ordered it new (just before gas prices started going through the roof) and got it fully loaded with the trailer tow package.

The SG unit in these is called a Trac-Lock and the clutches are located outboard of the side gears...not inboard so when you pull the rear cover off, it'll look like a regular non limited slip rear or SG and I don't particularly like them. I have a spreader but have never used it on any rebuild but using one is the 'correct' way but it may be easier for people who don't do rear ends much and don't know the 'tricks' of the trade.

The SG unit is called the carrier which the ring gear bolts to and there's no way the unit will come out without the ring gear coming out with it. Also, the crush sleeve on these look more like solid spacer than a sleeve and are very tough to crush. A solid spacer is easier to use imo. Also, I feel that is the problem why so many 9 1/4 rear ends are so hard on the front bearing is because so much pressure was used to crush it down to the proper preload.

 

[Coronet 500]

Interesting idea on the crush sleeve, I always guessed it was due to weak material and time not initial install, very good observation. 8 1/4" are 10 bolt cover, 9 1/4" are 12 bolt cover. I agree the stock 9 1/4" limited slip is a poor design and when you find a used one often it's so damaged they are not rebuildable.Here is Ratech that has solids. http://www.ratechmfg.com/chryslerspbs.htm