I want to get rid of the Vacuum actuated Dana 30...

T-Rex Jeepster

The Unoffendable
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Middle Tennessee
I'm sooooooo done with the inner/outer seals blowing out of the stock Dana 30 YJ front axle and want to get an earlier Dana axle housing that will bolt in without any modifications. I run all weather tires and do 99% of my Jeepin' on the highways and back roads with the occasional excursion off into a pasture of dirt road or two. So I don't mind getting by on solid axles and manual locking hubs. Will earlier
Dana 30's or 35's out of CJ's or Cherokee's or even Wagoneers bolt in to a YJ without any major headaches? Will the differentials swap over if there is a lot of years between the two? Any wisdom and advice is greatly appreciated. Thanks!!!
 
There isn't anything that will bolt in. CJs had a different width between spring perches and their axles are much narrower than YJs...54" on early narrow track years and 58" on wide track years. YJ was 60.5". Still won't bolt to the leaf springs anyways due to the distance between the spring perches. CJs are also low pinion, which isn't really ideal in a front axle.

Cherokees have the coil system up front that the TJ used, so automatic no there.

Wagoneers were a different leaf spring width as well. There used to be a kit from Dave's Customs Unlimited that had you cut off the YJ frame brackets and relocate them so that you could run a Wagoneer front axle. That might exist still, I don't know. However, Wagoneers are 6 lug on 5.5" spacing which is not at all close to what you need for a YJ, and rear axle options that work to match that are almost completely unavailable. I think an Isuzu Dana 44 is the only option there.

So, no, you are pretty much hosed. The only option really is to do the 1 piece conversion to your D30, or finally fix all the things that can cause the seals to go bad in the stock disconnect form.

If you keep getting passenger side leaks, you probably need to fix the bushing in the outer shaft that aligns the outer shaft to the inner shaft. If that connection is worn then the shafts will wobble and kill the seal. There is also a bushing in the axle housing that holds the intermediate shaft true. That might be worn and need replacement.

You also need to do a good job of installing the seal. Often times, installing the seal with all thread and washers doesn't cut it. It can warp the seal or install it crooked which doesn't last long. There are expensive tools sold for about $150 that can make it basically a completely perfect install, but obviously paying that is a bit much. The best chance of success is to fix the connection between the shafts so they run true and then use a proper tool to install the new seal.

Bottom line, there are multiple factors and when folks see a leak, most just replace the seal. Usually something killed the seal and a simple replacement will likely die a similar death in a quick time frame. In the case of the YJ you need to check the shafts to make sure they are not the reason for destroying seals.

You should not have left side problems unless you're using inferior seals, installing them wrong, or left side axle shaft has a groove worn into it that is too deep and keeps nicking the new seals.



The 1 piece conversion is an option that works decently well but it will spin the driveshaft which means you'll probably want a double cardan shaft installed up front. The stock u-joint angles are pretty terrible....both the front axle and the transfer case yokes point up. There's a good reason the TJ and XJ used double cardan shafts when the front was spinning full time.
 
The 1 piece conversion is an option that works decently well but it will spin the driveshaft which means you'll probably want a double cardan shaft installed up front. The stock u-joint angles are pretty terrible....both the front axle and the transfer case yokes point up. There's a good reason the TJ and XJ used double cardan shafts when the front was spinning full time.
Just a note on this bit. I have stock height springs on the front and have the CAD locked in. No vibration issues at all (I've had it up to 65ish), so this may be more of an issue for lifted rides.
 
Just a note on this bit. I have stock height springs on the front and have the CAD locked in. No vibration issues at all (I've had it up to 65ish), so this may be more of an issue for lifted rides.
It probably is more of an issue on lifted rigs, and possibly some that are geared lower. I for sure had vibes on mine at 2.5".

The angles are definitely not ideal when measured, even in stock form, but they may not be off by enough to matter.