Dana 30, refurb or leave as is?

[wadehiers]

This has probably been covered before... but I couldn't find it in search. I'm doing a complete restore on a 1982 CJ7 . I'm at the point of deciding what to do on the front axle. I've already pulled the axles and knuckles and I'll be doing a full rebuild at the hub end of things, my question is should I worry about anything at the differential? The axles came out pretty clean so I don't think I need to worry about the inner axle seals, but I have no way of knowing how the pinion seal is. (the axle had been pressure-washed before I could check for oil around the pinion tail.) Should I go ahead and replace the pinion seal just in case? Anything else I should be concerned with on a 37 year old axle that I don't have any real history on?

I rebuilt the entire AMC20 rear end (new seals and outer bearings)... but the quality of that axle is tough to compare to.

tks,
-Wade

 

[Patrick]

It depends on your expertise, time, money and restoration goal. The very least you can do is check gear lash and contact pattern and overall gear integrity like chipped or signs of excessive wear. You can accomplish this with just the cover removed and axle in vehicle. The pinion seal replacement is cheap insurance. Good luck!

 

[Basod]

Once you get it on the road the axle seal will start leaking and you’ll hate that you skipped it.
There not that hard to do since you already have it mostly apart just be sure to put some marks on the carriers so they go back the same as they came out and grease your seals.


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[Ultrunner]

Concur that you’ll kick yourself if you’ve gotten this far and end up with a leak you could’ve prevented.

Did you change the gear ratio in the rear and? I’m guessing not. A rebuild kit is about $100 and peace of mind. You could also replace the ball joints and u-joints while you’ve got it all apart. Again easy to do for peace of mind. I’d change to sealed u-joints with no grease fittings either. They’re stronger since there’s no channel for the grease.


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[mriplaybass]

As everyone above stated, it's about peace of mind. I definitely would replace all of the seals, not just the pinion seal. The inner seals are a real PITA to install because you have to remove the carrier, but now is the time to do it. If they are as old as you suspect, you probably damaged them taking the axle shafts out. When I completely rebuilt mine, the new seal on the driver's side began leaking within 4 years. Granted, lots of mud and such found it's way in there, but why mess around with potentially 37yo seals? Here is a video of how to change Dana 30 inner seals. It's a newer Jeep, but the install is the same.

https://www.youtube.com/watch?v=MbbbJI TYPED A BAD WORDKg&t=854s

If I recall, the back lash is somewhere around .006 to .009. On an axle that has been run for many years, that will increase due to wear and seating of all the components. Don't worry if it seems a bit loose. Check it with a dial indicator to be sure. If you don't have a dial indicator, you can get a rough idea using a feeler gauge, but that is definitely not the tool to use for doing a legitimate set up.
Make sure that you mark the carrier bearing caps and reinstall them in exactly the same position and orientation. If I remember correctly, torque is 60 ft.lb. I always use red lock tight on the bolts. Since you are just taking the carrier out and putting it back in, everything should be the same as it was when removed. I would not mess with back lash, carrier and pinion pre-load, or gear pattern. To change any of this requires removing the carrier bearings since the shims are inboard of the bearings on a Dana 30 . Since the bearings are pressed on, you need special pullers, or have to cut the bearings off and get new ones.
Now that I have rambled on, the bottom line is, look at the condition of things once you get the diff cover off. If all looks good, replace the seals and button things back up.

 

[wadehiers]

thanks everyone for the advice. After reading everything above, I've reluctantly given in to accepting that I will need to, at the very least, replace the axle seals (turns out that there is gear lube in one of the axle tubes, so I'm glad this thread has caused me to take another look at it), and check the lash on the pinion/ring gears. I'll post pictures once it's completed.

on a side note, has anyone found an aftermarket outer axle seal like the picture below that will work in the smaller tubes used on the CJ7 's version of the Dana 30 ? Seems like these seals are only made to fit the larger bore on a WJ or TJ.... ?

https://cdn3.volusion.com/ymcqg.kvqok/v/vspfiles/photos/SK22102-R-2.jpg?v-cache=1549560633

 

[caveman]

Those seals in the picture are good in theory but if any dirt or water does happen to get by them, It can't get out "My experience after running in the mud"

 

[mriplaybass]

thanks everyone for the advice. After reading everything above, I've reluctantly given in to accepting that I will need to, at the very least, replace the axle seals (turns out that there is gear lube in one of the axle tubes, so I'm glad this thread has caused me to take another look at it), and check the lash on the pinion/ring gears. I'll post pictures once it's completed.

on a side note, has anyone found an aftermarket outer axle seal like the picture below that will work in the smaller tubes used on the CJ7 's version of the Dana 30 ? Seems like these seals are only made to fit the larger bore on a WJ or TJ.... ?

https://cdn3.volusion.com/ymcqg.kvqok/v/vspfiles/photos/SK22102-R-2.jpg?v-cache=1549560633

I just picked up a set, but have not installed them as of yet. I plan on installing new axles and seals this week, so I will see if they will fit. As Caveman stated, if anything does get by the seals, it will be trapped inside the axle tube. I really don't run a lot of mud, so time will tell. They are only pressed in by hand. The outside is a ribbed rubber and does not look like it would be difficult to remove periodically to inspect. Might even be possible to remove the snap ring and remove the rubber seal and pull it back far enough to have a look inside without removing the axle shaft. All I know is that I have gotten a lot of crud inside the axle tube over the past few years, and it tore up the inner seal. I'd rather have to pull the axle shaft once in a while to look inside rather than have to remove shafts, and carrier to replace the inner seals. Time will tell!