jeep dana30 and 35 question.?

Question

How bad are they really. I mean, i am working on turning my yj into an off road machine, and i just wanted to know how easy are they to really break. I dont off road that often but i dont want them to break when i do. Is it a really good investment, or just a... well u can if u want thing. Imadding a 4inch rough country lift and a 2 or 3 inch body lift and the 3 inch tire combo on jcwhitney. Any suggestions on making it tougher. I fixed up the engine real well, new intake, exhaust, computer, ect. I just needsome imput for the under body stuff

Answer 1

As long as you are going to run 33" tires are so, the Dana30 will be fine. The Dana30 doesn't really have much problem handling 35s actually.

The Dana35 though is another story, 33s should be considered an absolute maximum on this axle, and you are still kind of pushing your luck.

The big thing to keep in mind here is after the larger tires, you'll want to re-gear the axles.

This FAQ link will explain the different axles, there's also a bunch of other good info in that FAQ about lifts and such.

http://www.cdmfabrication.com/bbb/viewtopic.php?t=58#14

Answer 2

The shortcoming of the Dana 30 series diffs is the axles. They break right at the drive splines. There are aftermarket axles which are stronger that can help a lot.
The problem is that the suspension lifts change the drive line angles, and the reason for the lifts is always bigger more aggressive tires that increase the traction and result in the axles being the weak link.
I have used these differentials for thousands of miles off road without a problem, but if you drive hard and fast off road, then consider changing to the Currie 9" Ford conversions.

Answer 3

Dana 30's on the front are pretty tough. One of my Jeepn buddies is HARD HARD HARD on his equipment and has never broken his Dana 30.

Now about the Dana 35, well sing this to the tune of "You picked a fine time to leave me Lucile."
Four rusted lug nuts and a leaky grease seal.
You picked a fine time to leave me loose wheel.
... went on some hill climbs. Been through some pond slime,
but this time we're late for a meal..
You picked a fine time to leave me loose wheel.

I ran 33's on my Dana 35 and lived in fear of the thing every time I left the pavement. Save you money and put a Dana 44 or Ford 9" under your jeep. Check out the link below and send Bill a picture of your jeep with the broken axle when it goes. (not if)

Answer 4

If you are serious about building an offroad rig Spring Over Axle (SOA) is the way to go. Build your rig in phases. Axles are a big investment, but Chevrolet axles will bolt right on to the jeep springs and solve the lift and axle problems way cheaper, simpler, and stronger than the way you are talking.

Check the links