Front axle swap?

I talked to a guy who said he has a Dana 30 with 4.10 gears and disc brakes.

Would this be an Ok swap for my original axle? I have. 57 cj5 stock with a fiberglass tub.

 

Narrow track or wide track?

What is the gear ratio in your Jeep's axles? IIRC the "standard" gear ratios were 4.27, 4.88 and 5.38.

 

As 68 Buick has mentioned you first need to be concerned about matching ratio's from front to rear...........If it is a narrow track it will be 3 inches wider , a wide track is 6 inches wider overall than your stock axle.........the good news is the spring perches on your old and both the newer axles are in the same location at about 27.5" C/C...........find out if you can what year it is or measure it from wheel mount to wheel mount...........53" narrow and 56" wide.

 

I will get more info.

I know there should be a tag on the 9 o clock here on the axle but, alas there is not. Will it be inside or will I have to count the teeth of te largest gear?

 

You should not have to count teeth. The tooth count is stamped into the edge of the ring gear. so if you see something like "43 8" that's 43/8 = 5.38 ratio.

You can also turn the driveshaft and count how many turns for one full turn of both wheels. Realize that if you hold one wheel still, you need to turn enough for two turns of the wheel in the air.

Check if your rear axle has a tag.

 

Ok. Thanks for the info gents.

I'll be out there most of the day tomorrow, I'll get front and back ratios and then take it from there.

I've read a lot of other posts regarding these things as well, I'm just assimilating information and a good clip this week. I'll take a couple snaps of the gears if I open them up for review as well.

 

Always need to pull the cover off an axle to check condition before you buy it. Look for any broken teeth or a diff full of sawdust.

 

Realize that the ratios MUST match, front to rear. It's usually a pretty good assumption that if your rear axle is one ratio, the front must be also. Otherwise the Jeep would bind up or break when you put it into 4WD.

The front and rear don't have to be exactly the same ... you can have 4.09 and 4.11, or 4.88 and 4.89, something like that. That's acceptable because 4WD is only operated on loose surfaces.

We have seen cases where the front and rear ratios are different - ie a clueless previous owner (PO) installed some random replacement axle and sold the Jeep to an unsuspecting new owner. So don't assume.

 

Well, that's good to know! Since the Jeep has no lock outs it's real time 4wd, correct?

I've never driven it more than around my grandparents farm and didn't fall apart then! So, although I won't assume, I'll hope!

 

Oh no, that came waaaaaay later, like the early 70s. Locking hubs are an accessory - they were not included with the Jeep from the factory. You don't need them - but they are nice to have if you drive on the pavement a lot. As long as you shift out of 4WD, the front axle does nothing - it just rolls along with the Jeep.

You need to understand what the shifter does. You have high and low range, and 2WD and 4WD. 2WD is just that, just like a passenger car. 4WD is for off-the-pavement only.

If you only have driven it on dirt, that's not conclusive. You are very likely ok, but don't assume.

 

I guess a year + just passes you by...


Still looking at this as a possibility. The donor was an 81 narrow track so, that makes it 3in wider or 1.5 on each side.


I have a stock axles with 5:38 gearing...the D30 that has been sitting around has 4:10 gearing. Obviously, that's not going to cut it front to back but, I've opened up a whole new can of worms by getting the entire front axle, steering, and braking components from this same donor. Tilt shift column and all. So, would I need to match the gears front to back or back to front? I'm also exploring the possibility of just disengaging the front end from the drive shaft just to roll down the street.


What would regearing the rear cost as a rough guesstimate? I see the Ring and Pin run anywhere from 140 and up on the big sites but, there's got to be a wee bit more to it than that, no?

 

What are you really hoping to gain by doing this swap?

 

The positive gain for me is disk brakes and power steering. The research i've done led me to the D30 as a suitable application for this and I was able to keep cost down by bartering my labor for most of the parts.

It's never going to be a crawler or heavy trail riding Jeep. At most, through the field and around the farm in the summer.

 

Thanks for all the responses guys.

I guess seeing as I have all the components now and I bartered my labor for them, it's still a solid swap. I got the axle with the discs, the saginaw and the pump, the tilt column, and he also gave me the dual MC and the brake booster, along with all the pedals. So, paying for a re-gearing would be $400~

On the other hand - I've got a saginaw box already so, with a kit and some of those double ended joints for the shaft/connection I'd still be around the $600~

 

As mentioned in previous posts, the NT Dana 30 is a great swap. But expect to spend $150 on bearing kit, $200 on a gear set, plus about $300 for a re-gear. That's true whether you do the front or rear. I'm a low speed, off-road guy, so I would put 5.38 in the front rather than 4.10 in the rear but you need to know for sure what your plans for the jeep are. Any on-road work and the 4.10's start looking good...

 

A stock 57 will be the T90A and its 2.79:1 first gear. 4.10's are going to be a bit of a handful with the F head and not something I would recommend even with stock tires. As above, find a set of 5.38's for the D30 to match the rear (assuming that's what is in it).

 

I'm still trying to figure out this whole gearing situation. I plan on mainly paved roads...the tires are currently 235/75/15.

So, you're saying that the lower gearing is ideal rather than higher? I'm also unsure of how the first gear and low power motor factor into the running gears. Is it that the engine has to work harder to spin the shafts a faster revolution? As much as I try not to be ignorant, I'd rather ask and learn then guess and be wrong.