D60 35 spline upgrade and 30 spline limitations.

[rebar]

Sorry for such a newbie question.. But could anyone please explain, or direct me to the explanation of what it takes to convert a Dana 60 rear to 35 spline? I'm considering it since I need a new limited slip or locker.

Also.. what are the limitations of a 30 spline D60? I plan or running 33's maybe and need to tow a 9k pound camper.

Thanks

 

[bfdiesel]

Have you ever broken a 30 spline dana 60 axle shaft? Not sure it is worth it running 33" tires. Looks like you will need to bore out the spindle if you do: http://naxja.org/forum/showthread.php?t=933793&highlight=D60+boring.
You could always look for a 70 or 80 with bigger axles.

 

[rebar]

Have you ever broken a 30 spline dana 60 axle shaft? Not sure it is worth it running 33" tires.
You could always look for a 70 or 80 with bigger axles.

No, I'v never broken anything because I haven't done any serious off roading yet. Im in Iowa

I plan on doing some hill climbing to get to remote locations though. And cant find any info on the limitations of the 30 spline axles. But I figured if Im buying a new ARB locker or limited slip unit,, now would be the time to upgrade, if I really need it.

 

[bfdiesel]

Well start by measuring to see if you will need to bore out your spindles or not. From what I can find some will need it and some won't. If it doesn't need bored out then you need to set up the carrier and put in the new shafts. Boring will add a step.

What is this in? Are you climbing these hills while pulling a 9k trailer? If not you probably don't need it, you could also look into chrome moly shafts.

 

[blakeape]

I broke a rear 30 spline Dana 60 in my wheelin rig on the Rubicon. The axle shaft actually broke, then jammed and ripped the main bearing caps off the case. I had a spool with 5.38 gears. This was in a Toyota with 39.5 inch tires, but I would never trust a Dana 60 behind a Cummins or a heavy rig. Don't waste the money of an ARB, gears, install kit labor, etc on a rear Dana 60. You would be way ahead with a Dana 70, 80, 14 Bolt or the Ford 10.25/50 rear end. I have seen many failures of rear Dana 60's and spent a 1/2 day on the Sledge Hammer trail at KOH this February in my Tacoma dragging and winching a Jeep JK with a shattered rear 60. It's only a 9.5 inch ring gear.

 

[Spargman]

Also to be fair, many guys can make a D60 survive some pretty tough stuff. Heck, I wheeled the Rubicon in my Tahoe with the IFS and a upgraded 14bsf....but i had to go painfully slow so I didn't break anything (mostly clearance issues).

With 33's and if you're not hammering the heck out of the throttle, a D60 will be just fine....unfortunately I'm not as familiar with the 30 to 35 spline conversion. D70/80's and 14bff are for running 37"+ and when hitting the throttle hard is commonplace. IMO, the extra weight of those axles is not necessary if the truck sees DD duties. However, if it's a trail rig, then upgrading can make a lot of sense b/c of the extra insurance.

Which vehicle is this axle for? Is it the OEM axle or one you've bought and thinking of upgrading? What type of wheeling do you plan on doing with the vehicle?

If it's just to climb hills for exploration as you mentioned, IMO that D60 is more then enough. I towed a 2.5klb trailer behind my 6.5klb Tahoe and I've never had a problem even running IFS....and that includes climbing hills with it and in 4x4.

Now, if mud bogs are in your future, then grabbing one of those heavier axles would be a great addition.

Throttle modulation is one of the biggest problems drivers face. The more careful you are, the longer your axle will last.

 

[rebar]

Thanks.. My D60FF is in a 1995 E350 cargo with nv4500 and 1st gen stock 6bt in front.

I'm not sure how many mods I will do. Iv considered 4x4 , adding water/meth injection, nitrous , etc. And I do want to be able to hammer on it and have good hill climbing abilities. I don't want to be limited. The vans main purpose is to tow my toy-hauler through the Rockies. Then take me further. It wont be a DD.

First thing I need to do is check the bore in the D60 spindle. I didn't know my D60 might already except 35 spline. Thanks bfdiesel.
If its to small, I will start to look for a D70HD , which came out of a 99+ cutaway with rear tank.. I hope they aren't to rare. But the D70's still will have 9.75" gears.

blakeape. Id have to agree with you.. Between the Dana 70, 80, 14 Bolt or the Ford 10.25/50.. Which one would you pick for my E350?

====

SRW van and SRW cutaway with midship tank, D70 = 66.4" (hub face to hub face)

SRW cutaway with rear tank =72.1". This puts the stock 245 tires are 82" wide 5.7" Difference

 

[Outback]

The rear D60 is plenty strong. With 33" tires I dont see you ever having ANY problems. Im running 37" tires on my front Dana 60 that has 30 spline stub shafts and I have never had any problems. Its SO MUCH easier to run Chromoly axles shafts than to try and do a complete diffrent axle swap. Your Dana 60 out back is plenty strong. Remember this. Any THROTTLE JOCKEY can break ANY axle. With enough wheel spin then instant traction is what eventually breaks axle shafts. Save your self some serious headaches and spend your cash for a set of simple to swap in Chromoly axle shafts. And then ONLY if you are really paranoid or swap on a set of 40" boggers.


Just know you can either run the stock size 30 spline Chromoly OR 35 spline Chromoly shafts. You would need a boring tool for the 35 spline but those are easy to get or have someone bore it for you for around $250. The link below was one of many after doing a Google search. I hope this helps.
http://eastcoastgearsupply.com/c-27...shafts-rear-dana-60-chromoly-axle-shafts.html

 

[bfdiesel]

A dana 70U has a smooth teardrop bottom, if you are concerned about diff clearance out of the box. Sterlings come in Fords so a 10.25 or 10.50 may be a good choice. Might find some older 70's or 80's in your width range. I wouldn't be afraid of any of those axles. However if you put a 14 bolt in some chevy guys will pick on you.

 

[blakeape]

To Outback:
A front Dana 60 is a whole different beast than a rear. 30 spline stubs are fine because the investment in a locker or gears is not wasted with the stock inners being 35 spline. Yes you can spend your $ on the ARB and gears initially and upgrade to 35 spline stubs and lock outs down the road.
The rear is different, if the OP spends money on a 30 spline ARB and some cromoly then axles slaps them in the rear of his heavy, Cummins powered full size van and it doesn't hold up he's out a bunch of $$. Your truck has a 14 Bolt rear right? That's a 10.5 inch ring gear and the pinion support bearing makes it very strong. Plus they are cheap and easy to work on.

To Rebar:
I'd consider a 14 Bolt if you don't care about ABS, otherwise a Ford 10.25 or 10.50 might be a little easier to swap in and play nice with the rest of the Van. Both are very strong and relatively cheap. I paid $75 for the 14 Bolt I swapped into my 1 ton Tacoma.

 

[Outback]

Blakeape,
Yes I understand the Dana 60 front and rear axles are two diffrent beasts. You have some VERY valid and solid points. My thought though is that he only plans to run 33" tires (maybe) and towing only a 9K trailer. I dont see any issues with a stock Dana 60. We dont know his skill level or pocket book capability. A Dana 60 is not a weak axle. He has a stock Cummins that he may upgrade. I agree with you that if he really wants a massive stronger axle then a Corp 14 bolt is the way to go. But for now maybe a set of 30 spline chromoly axles. A detroit locker would be a huge improvment in the off road department as well. Just giving him a few more options.