Dana 30 Narrow track in an MB

What exactly is involved in the conversion? I'm looking at a local axle from a 79 CJ. I know I will need to re-gear it to match my rear, and at a minimum add a proportioning valve (It has disc brakes) or a new master cylinder. Any other issues/pitfalls I need to be aware of?

 

Reversed shock positioning on the spring plates.
Can leave the frame shock mounts in position if you reverse the mount at spring plate.
Or else move the frame shock mounts to a new position behind the axle.

Need to put castor wedges between springs and axle perches.

 

Well, its wider by like 3 inches than the D25. Uses different drag link steering setup. If you put in front disk I would definitly put in a dual master cylinder. You will need new flex brake lines and I would make new ones from the master to front anyway. It will pretty much bolt in though.

I installed a d30 in place of my d25. Its pretty easy and the mission creep stuff is easy too. I regard mine to run 5.38 ratio too. I regret not finding a power lock or other form of locker when i did it. I installed all new bearings, gears and an open case too. I installed new Ujoints on the axle shafts too.

Need 6~7 degree caster shims.

I would do it again. In fact i would never bother with a d25 or 27 ever again.

 

This is what I am looking at: 1979 Jeep CJ5 Dana 30 front axle

Already has disc brakes. I want to finish my engine swap before I put a new front axle (already have a 44 in the rear). But it seems like a decent price. Then again, I don't know. I would just be getting it to sit in the garage about 9-12 months before I tackle that project. (I want to play with my new V6 a bit before I down the jeep for another project.)

 

The main reason I am looking to upgrade. Silly me thinks that my '42 should go run the Rubicon in 2017 for its 75th birthday......

 

The post 1975 CJ D30's all have a bumpstop plate cast onto the carrier housing.
I recommend cutting/ grinding the ugly bumpstop plate off.

 

I did it for better turning radius, no more leaking knuckle seals and no more king pins.

Here read this Best narrow track Dana 30 iteration questions | EarlyCJ5.com

 

Weren't the springs wider on the newer axles?

 

I believe they were. I'm pretty sure I will either need to trim the perches or weld new ones on - Maybe I could even correct the castor when putting new perches on?

 

I just put a D30 in my 3A. Everything bolted up. I had to elongate the holes in the U-bolt plates for the slightly larger U-bolts. The stock steering worked fine. Even reused the original brake line. I had to drill and tap a hole for the Tee that bolts onto the long axle tube. No caster shims are needed. The pinion angle was the same as the old D25.

 

The shims are not for pinion angle but for the steering to work correctly. Less caster creates wander and other steering issues. The accepted caster is around 7*. you can measure it with an angle finder.
best way to check and set caster | EarlyCJ5.com

Instead of elongating the Ubolt plates, I made new ones and used new 1/2 u bolts I bought from Stengel bros Leaf Springs, Air Springs and Suspension Parts and Service.

 

Oh yeah, the lower ball joint has to lead the upper one.

 

All CJ leaf springs were 1-3/4" wide through 1975.
Yes it's certainly possible to adjust the castor angle when the perches are welded on.

 

This quote says it all.
I would do it again. In fact i would never bother with a d25 or 27 ever again.[/QUOTE]

 

Well I bought it. Paid $200. Spring perches measure 1.75" Set it aside until after I get the V6 in, but it will make a nice build eventually.

 

Putting one in my 47 2a as we speak.

 

Nice. I am interested in hearing any pitfalls or snags you run into.

 

I checked the caster angle in mine. It was 5* and that is with no engine in it, so it should get better with the springs compressed.

 

One of the challenges with the MB is that the steering bell crank is mounted to the front axle and not to the frame like it is on a CJ2A or any of the newer Ross steered jeeps for that matter. You either need to relocate the bell crank to the new Dana 30 or to the MB frame. Or ditch the Ross and go Saginaw.

I too am in the group for ditching the 25 for a 30. EXCEPT, maybe, in the case of an MB.

 

I already had a manual saginaw when I bought it, and am putting power in it during the engine swap...