Dana 30 inner axle seals

[88mancheman]

Hey all after a recent wheeling trip it seems my vent tube seemed to squirm off and it’s more than likely muddy water has gotten in there I’m going to pull it all apart and clean it up replace the seals and fluid and fix the vent tube this weekend but I’m seeming to have trouble figuring out which inner axle seals I will need for a Dana 30 non disconnect axle I’ve found many different brands and part numbers and I’ve come down to these part numbers from spicer : 46470

&

42500

Will these work or are these for the CAD axles?

Hopefully someone here has tackled this before and can help me out

[DesertRat1991]

For the D30 non-CAD you want Spicer 46470. You need to buy 2.  The new seal is shown on the left, the old seal is on the right:

 

 

[Dzimm]

While you've got it apart, put on some outer seals.  The factory didn't have them but there are many options available in the aftermarket.  They will keep the dirt and mud out of the axle tube all together and prolong the life of the inner seals.

[88mancheman]

For the D30 non-CAD you want Spicer 46470. You need to buy 2.  The new seal is shown on the left, the old seal is on the right:
 

 

Thank you for the quick reply I have 2 of them on there way! The parts store as kept insisting that 42500 was the same thing but I know better than that

[88mancheman]

While you've got it apart, put on some outer seals.  The factory didn't have them but there are many options available in the aftermarket.  They will keep the dirt and mud out of the axle tube all together and prolong the life of the inner seals.

Thank you for the recommendation, I have some of those ten factory outter seals on order currently will those suffice? I’m also seeing some alloy USA ones and a few other brands that just get more and more expensive but how important are these seals? I’ve been reading that they are a bad idea as they can trap water in and can possibly reduce the life of the inner seal and axle tubes as water can get trapped inside the outter seal is this just someone’s myth from not greasing them often or a realistic concern?

[AZJeff]

1 hour ago, 88mancheman said:

Thank you for the recommendation, I have some of those ten factory outter seals on order currently will those suffice? I’m also seeing some alloy USA ones and a few other brands that just get more and more expensive but how important are these seals? I’ve been reading that they are a bad idea as they can trap water in and can possibly reduce the life of the inner seal and axle tubes as water can get trapped inside the outter seal is this just someone’s myth from not greasing them often or a realistic concern?

I have mixed opinions about those fancy type outboard seals. People who do a lot of driving in deep mud might find those type of outboard axle seals useful.   There is, of course a possibility that mud can become trapped between the inner and outer seals if the mud is thin enough in consistency.  (The inside of the axle tubes are not particularly smooth, and thus getting a good seal there is problematic)     In other words, they may "fix" one issue, and possibly introduce another in its place.

 

If you drive in dust/dirt like I do, the factory plastic seals are just fine, as they keep rocks out of the axle tubes.   This is what the factory intended, in that big "chunks" don't get into the tube, yet minor water and dust gets in (and then gets back out).

 

Regardless of the type of seal you choose, it doesn't mean you can submerge your axle housing with great regularity and for any length of time.   The inboard seals are designed to keep oil IN, and don't do much to keep water OUT.   YMMV.

[Dzimm]

8 hours ago, 88mancheman said:

Thank you for the recommendation, I have some of those ten factory outter seals on order currently will those suffice? I’m also seeing some alloy USA ones and a few other brands that just get more and more expensive but how important are these seals? I’ve been reading that they are a bad idea as they can trap water in and can possibly reduce the life of the inner seal and axle tubes as water can get trapped inside the outter seal is this just someone’s myth from not greasing them often or a realistic concern?

I haven't seen anyone with actual problems due to the outer seals, mostly just speculation.  It makes sense that a seal would keep water from coming out but if it seals water from going in to begin with, you shouldn't have water on the inside to get trapped. 

 

Now if you do regular water crossings I would maybe be a little more concerned as it certainly could seep in being submerged.  A simple crossing the creek once in a while should be no issue.  

 

The trick to get a good seal on the outside is to sand the axle smooth where the seal rides so it has a nice even surface and make sure you put enough grease in it and maintain it.

 

Since you've got the factory outer shields on order already, just use those.  Theses trucks are 30 years old and plenty are still running on factory axle seals so they obviously work well the way it was originally designed.  The sealed aftermarket seals are just nice insurance imo.  

[88mancheman]

I have mixed opinions about those fancy type outboard seals. People who do a lot of driving in deep mud might find those type of outboard axle seals useful.   There is, of course a possibility that mud can become trapped between the inner and outer seals if the mud is thin enough in consistency.  (The inside of the axle tubes are not particularly smooth, and thus getting a good seal there is problematic)     In other words, they may "fix" one issue, and possibly introduce another in its place.
 
If you drive in dust/dirt like I do, the factory plastic seals are just fine, as they keep rocks out of the axle tubes.   This is what the factory intended, in that big "chunks" don't get into the tube, yet minor water and dust gets in (and then gets back out).
 
Regardless of the type of seal you choose, it doesn't mean you can submerge your axle housing with great regularity and for any length of time.   The inboard seals are designed to keep oil IN, and don't do much to keep water OUT.   YMMV.

Thank you for the response, I don’t do a lot of mud wheeling or major water crossings but when doing major fixes such as this I always like to upgrade when I can so I hopefully don’t have to go back to it anytime soon just I n case there is that one time I end up in a decent crossing or mud pit, I just received both the stock outter ring “seal” things and some aftermarket ten factory greaseable outter seals and am still debating on what to put in when I do this next weekend, I’m leaning towards the factory rings as the factory designed the Dana 30
To be this way but just hoping there is someone out there with them on there MJ who could chime in as well to change my mind before i just throw some new factory rings on :)

[88mancheman]

I haven't seen anyone with actual problems due to the outer seals, mostly just speculation.  It makes sense that a seal would keep water from coming out but if it seals water from going in to begin with, you shouldn't have water on the inside to get trapped. 
 
Now if you do regular water crossings I would maybe be a little more concerned as it certainly could seep in being submerged.  A simple crossing the creek once in a while should be no issue.  
 
The trick to get a good seal on the outside is to sand the axle smooth where the seal rides so it has a nice even surface and make sure you put enough grease in it and maintain it.
 
Since you've got the factory outer shields on order already, just use those.  Theses trucks are 30 years old and plenty are still running on factory axle seals so they obviously work well the way it was originally designed.  The sealed aftermarket seals are just nice insurance imo.  

Thank you for the response I’m leaning towards the factory outter as you stated it was designed that way and most of them have been just fine that way, I like the extra insurance but I’m not sure if it’s the best choice for my type of wheeling, I live in Cali and I’m trying to move the project alittle more towards a weekend crawler type rig (hopefully one day I can possibly take it to Moab or Shaffer lake or the rubicon without ruin any body panels) more than anything else, I do like to just go have fun on random back roads and what not and sometimes that includes a little bit of mud & water but I’m starting to think that the factory outer “seals” are just fine and that I’m going to have to drown the axle pretty completely and for a good amount of time for that axle tube to fill up, I don’t ever plan on that and I guess if I do that a whole seal replacement & fluid change would be in order afterwards anyways so I’m thinking those outers are more trouble that they are worth as they could hide a leaking axle seal or a packed axle

[gogmorgo]

The inner seals should be fine against water intrusion, so long as your vents are clear. When you put your diff into water, the warm air and oil inside get cooled off, which drops the pressure, and everything contracts; if fresh air can't come in the vent quickly enough, it may start pulling stuff through the seals.

[88mancheman]

On 7/7/2019 at 6:09 AM, gogmorgo said:

The inner seals should be fine against water intrusion, so long as your vents are clear. When you put your diff into water, the warm air and oil inside get cooled off, which drops the pressure, and everything contracts; if fresh air can't come in the vent quickly enough, it may start pulling stuff through the seals.

Thank you for the food for thought! I never truly understood why vents where there other than to keep mud out & water out and oil in but I guess I learn some new knowledge everyday!!! based on your statement would you recommend against installing the outer seals on the axles as the inner ones are more than sufficient for there purpose? I think I've already come to that conclusion but I'm one of those who likes to get opinions from as many as I can and wager the pros and cons on things like this 

[gogmorgo]

I've never run outer shaft seals so can't really comment. I can see them being advantageous if you do a lot of deep mud, just an extra barrier to keep chunks of stuff off the inner seals. I have yet to see an axle shaft with a proper sealing surface machined into it though, so I do expect a non-perfect deal and that trapping water behind them could be a thing. I don't know if I'd want to run them on something that regularly sees road salt, for example, just because the axle tubes might not drain so well.