That does not do me any good if I get a 9

 

Information seems kinda up in the air still. Is there a good place with photos of the various pumpkins to determine the gear ratio? Sure I can use a mic and measure the axle housings for 9.25" then if I find one...jack it up and spin the wheels to determine LSD. If all that checks out then I need to determine the gear ratio which I'm not sure how to do without taking the pumpkin apart? Still after that 3.9:1 but with all this in mind it still has to be 5-lug...so 87-90 Dakota's (which did not have a V8 there for why a 9.25?) or a Jeep which also did not have a V8 big enough for a 9.25 so my only options sound to me like looking 92-09 Dakota & Durango (Ram?) then finding some x? spline 5-lug axle shafts for the rear?? Or am I over complicating this by having to have a 9.25 instead of an 8.25 on my 5.9L??


I did find this which might help...maybe the 7/8/9 is not the axle housing diameter? haha I don't know I reread this thread, this shows the Dana & Chrysler axles:



What do I have? It looks like a 9.25" but it's missing a few bolts.

 

Most of the sizes in that chart are going to be diameter of the ring gear inside the differential. The ones that don't follow that rule is the Dana's, they just increase their size as the numbers increase but nothing in proportion to the actual ring gear size. Dana 44 is 8.5in just lightly larger then the Chrysler 8.25. As ring gear size increases so does the over all strength of the entire system.

To find out the gear ratio you might get lucky some have tags with it stamp on. Most don't though. The best way is to spin the wheel and count the number of turns of the driveshaft to determine 1 spin of the tire equals 3.9 turns of the driveshaft. Most common ratios are 3.21, 3.55, 3.9. A few Rams may have came stock with a 4.11. The higher the number the lower the gear ratio is and the more torque you will get at the wheels. 3.9:1 is good for stock.

To find out if it has a LSD (Limited Slip differential) (Or a posi as it might be referred to by some) spin one wheel, if the opposite wheel spins in the same direction it has a LSD/Posi or a locker. If the opposite tire spins the opposite directions as the tire you are spinning then it is an Open differential (95% of axles have it). You can always install a LSD or a locker to an open axle for greater traction. Most junkyard/used LSD axles will need to be rebuilt with new clutches to get best traction. Over all best traction will be a locker with full 50/50 slip power to the wheels. LSD will be lucky with new clutches to do 25/75.

You have a Chrysler 7.25. You should upgrade to a Chrysler 8.25, which is more then strong enough for the 5.9 Magnum. (I still have mine and look what I put it through) If you get one from 87-96 it will be a direct swap. Yes from 91-up Dakota's used the 6 lug pattern. You can swap the axle shafts to convert to the 5 lug. Or swap your front knuckles to convert to the 6 lug. Or just run different lugs and use a converter spacer for the spare if needed. Don't let the lug size be the determining factor on passing up on a strong axle.

The Chrysler 9.25 mostly came on Rams which is wider and will stick out too far for most people tastes. The only narrow Chrysler 9.25 is what came on a few 99?-03? Dakota's and Durango's mostly with the 5.9 R/T. Some even came with rear disk brakes if I remember right. The 97-up Dakota and Durango axles will need a little work to fit. There is a write up in the FAQ2.

Also keep in mind the 2wd and 4wd axles are mounted differently to the springs. But they are interchangeable with installing new spring perches.

Another note is that the 1st Generation Dakota Chrysler 8.25 came with 2 different brake sizes. 9in or 10in. The larger the brakes the better. The 9.25 came with 11in.

 

So Ram axles are out of the question, I am left with Dakota and Durango up through 03' but would you find a 9.25 on a 5.2L?

"You can swap the axle shafts to convert to the 5 lug. Or swap your front knuckles to convert to the 6 lug. Or just run different lugs and use a converter spacer for the spare if needed. Don't let the lug size be the determining factor on passing up on a strong axle."

^ I actually have to have a 5-lug, so axle shaft swaps are going to be a must for the rear if I can find 5-lug shafts with the same number of splines. If my axle has 9" brakes I will ditch them anyway because I do not plan on driving that truck until the rear disc brake conversion is complete.

Thanks for all the great thorough info.

 

It is up to you if Ram's axles are out of the question. They will work.

In your quote of my statement I was talking about converting the 5 lug to 6 lug to match the new rear end. The Dakota/Durango only came with the 6 lug which there is no trick to convert to 5 lug without custom axle shafts.

 

I would probably put a 9" Ford in it.

 

Well if a Ram is wider as you said then that won't work unless I can widen the front by the same.

Aw crap I don't think I will find a 9+ in the 5-lug configuration then, I might have to settle with an 8.25

Ford what, Ranger?

 

9" Ford rear ends came in everything from pickups to Lincolns. But you can buy one made to fit pretty much anything. They're strong in stock form, but can be made ridiculously strong with aftermarket parts. It's probably the most customizable axle in existence and has the best aftermarket support. Places like Currie Enterprises can build you a trick 9" axle (at a price), but it's pretty easy to do your own if you have decent fabrication skills.

 

well on the brightside, you can get powertrax kits for the 8.25 still, that way you get factory optioned lsd with only swapping axle shafts and putting new brakes on a yard axle

 

Seriously, unless you're planning lots of HP or you drive abusively, the 8.25" rear should be fine (but I would lose the factory LSD).