Murf

Hey All,

Long story short, my '92 W250 has a 9.25 under it for some reason. Upon doing brakes I find it's giving up the ghost and decide to put the "Correct" axle under it.
What my plan is, since I want to do a Hydroboost upgrade sometime real soon, I figured I'd go ahead and put a 2nd gen Dana 70 under it with discs.

Question is, will the 2nd gen Dana be a bolt in deal, or should I prepare for some fab work?

My main concern is the spring perches. would they be the same width?

Thanks all!

Murf

gorms

I'm pretty sure a 9 1/4 rides on 2.5" springs and D70 is 3". I'm not sure how the driveshaft will bolt back up for sure, I know a d70 requires a longer shaft then a d80.

joem

wow, didn't know that they put a 9.25 under a cummins, makes ya think that dodge really under estimated the Cummins by oh.... ALOT

oliver foster

9 1/4 axles DID NOT come factory in Cummins trucks.

Spring perches are the same width 1st gen to 2nd gen.
The 1st gen have a 2 1/2 in wide leaf spring, the 2nd gen have a 3 inch wide pack.

Finding a DISC braked 2nd gen Dana 70 will be the hardest part of this swap.

Murf

Yeah, Sorry guys! I didn't mean to imply that the axle was factory.

My door jamb tag says the rear axles are rated for 6084 LBS and there's NO way this 9.25 would do that safely, for very long anyway.
Oliver, Thanks man! That's what I wanted to hear. I didn't figure there could be that much difference. That's a huge load off my mind. And Yes, The D70 rears with discs are kind of tough to find, but I've got one "almost" nailed down.
And yeah Gorms, the drive shaft is something I'm concerned about too. Not only the length of it, but I'm also wondering if the U-joints are the same size from 9.25 to Dana 70.

I'm gonna go talk to google about that very thing.
Thanks for the help guys, keep it coming.

Murf

joem

I scored a disk 70 off craigslist, some dude rolled a 2001 automatic and was parting it out. $200 well spent, The parking brake is my only issue

j.fonder

I suspect the driveshaft will need to be shortened as well as bigger u-joint to accommodate the bigger yoke on the 70. any reason to not look for a disc brake dana 80 from a late 2nd gen?

a 2nd gen axle is going to be wider than a 1st gen axle.

i'm going to play devil's advocate and say that a 1st gen dana 70 with big drums is a better braking axle. better e-brake as well.

oliver foster

I bet you can swap out the yokes for the T-case and axle to match up the driveshaft, if needed.
There is also a solid chance that the rear driveshaft is not a stock CTD one, as it easily could have been swapped out at the same time the 9 1/4 was installed...

Yes the rear axles are slightly wider on the 2nd gen but not that much. 1 1/2 inches a side on a SRW axle if I remember right.

dngurney

Okay,kinda confused and since I've been considering doing some type of rear disc brake upgrade and hydroboost I'll ask now in hopes it can help .why not a sterling axle ,to match other brake upgrades?

oliver foster

Why would you use a Sterling axle is my question when 2nd gen Dodge stuff is basically a bolt in?
I also like too keep my Dodge trucks, running Dodge parts.

Murf

Amen Brutha!


BTW, short update for those that care. '01 2500 Dana 70, Bought. $350!
She's needed a real good cleaning/painting, and a reasonable amount of parts.
Hope to be putting her in here in the next few weeks.


Thanks again for the help ya'll!

oliver foster

$350 is a good price!
Well done.

Murf

Yes, in most cases it would be. But I'm already at about $400 in parts, and it's still not in.
Most important lesson thus far is. If you buy a used Disc brake equipped Dana 70. MAKE SURE it has good backing plates/dust shields!!! Because if you want a functional E brake you HAVE to have them. And guess who's got the market locked down on that, Ma Mopar.
Don't get me wrong when you get em you get the cast steel bracket that bolts to the axle flange, the backing plate, and a brand new E brake kit all complete and ready to bolt on. But MSRP is $238! but I found a dealer selling them for $159 per side (both sides are covered by one part number)

Just words of advice for anyone looking to do the same.