Gear ratio spitballing, dana 30 carrier split.

Hey guys. I'm rusty on all the old small axle tech, been running one tons too long, so I'm trying to refresh. Friend has a huntin' CJ-5 with a 304, and a truck T-18 with granny first, 31s, stock gears and axles, we think they're 3.73. He uses it pretty hard and it needs to be reliable. He's thinking about going to 32" tires and a locker or limited slip in the front, as well as going to 4.10s. He wants lower gears, but still cruise the highway, 65 I'm guessing. I'm thinking he should go limited slip in the front as is the rear to avoid popping a front shaft with the V8. I have a D30 with a broken housing and an Aussie locker with 4.88 gears I might give him. What do you guys think about the ratios, and will the 4.88 Aussie work with the 4.10s? I calced the 32s and 4.10 to 2800 rpm @ 65.

Thanks

 

The differential CASE split on a Dana 30 is 3.73-1 to 5.38-1 ring and pinion and 3.54-1 to 2.54-1 ring and pinion.
The carrier on a Dana axle is the part the axle tubes are pressed into.
The CASE is the part that the ring gear bolts to and houses the differential gears (pinion and side gears).
4.10'a would be a good compromise but a lot of money/work for the change.
Also, a limited slip is going to add more stress to the front axles than an open differential, although would be easier on them than a locker.

 

Can you elaborate a little on this, Nickmil?
One of the reasons I put a powerlok in my front axle (a 27, not a 30) was because I heard it makes it less prone to breakage.
Also, it would seem to me that by dividing the load more or less equally between the 2 sides, a limited slip would reduce stress on the axles and hubs...am I thinking backwards here?

 

Actually you are. You are increasing the load on each individual shaft, u-joint, hub, etc.. With an open differential that has more give the load on one shaft can be transferred, thus divided more evenly between the shafts.
Think of this way, you have one wheel in the air, the other on a hard surface. You manipulate the locker or limited slip so the torque is driving the wheel on the ground. All the load now is on the axle shaft that is on the ground driving the Jeep. With an open differential the load is transferred to the wheel in the air so there is almost no load on the wheel on the ground. Unfortunately this doesn't give us any help in the form of forward movement.
The Powerlock is stronger than an open differential as it has two pinion shafts, 4 pinion gears, heavier/thicker case, but it will increase the load on an individual shaft. Because a limited slip (like a Powerlock) has some give they are typically much easier on the shafts than a true locking differential like a Detroit, Lock-Rite, etc.