High pinion Dana 30 questions

[Astala3]

I pulled this HP Dana 30 from a Yj. It has the CAD unit. Guy I got it from said that the previous owner got rid of the 2 piece passenger axle shaft and installed a solid shaft from an XJ. I was please to find that to be true.

Since it came from a leaf spring jeep, I figured I’d throw a truss kit on it to help locate all the necessary brackets. In doing so I had to further delete the CAD box.

Next was a Torq Locker. I was pleased to find all the gears and such in great condition! Locker is in. I did have a terrible scare! Broke one of the ring gear bolts off, when trying to reassemble. Praise God. I was able to back it out enough to expose the fracture before the head spin off. Grabbed the broken nub with pliers and spun it out! Thank you Lord!

With the carrier out, new seals are next. This is where the head scratching begins. Perhaps I overlooked somethingIn my research of the HP unit. The long side has a different seal than the short side. Also, there appears to be some sort of soft rubbery gasket surrounding both seal. Almost seem as though the seals are both seated within this red gasket then pressed into place. Any and all info is appreciated.

 

[tworley]

Don't pick at the red. That's where they pressed the tube into the diff.

Inner seals should be the same. Likely you have one that was replaced at one point.

 

[machoheadgames]

Don't pick at the red. That's where they pressed the tube into the diff.

Inner seals should be the same. Likely you have one that was replaced at one point.

Seals aren't the same on a CAD axle.

 

[tworley]

Seals aren't the same on a CAD axle.

Learn something new everyday. Whats the difference between the CAD and non CAD seals?

 

[machoheadgames]

The factory CAD axle has a seal at the CAD for the right side, and a seal at the diff on the left side. The left side seal is the same seal that the TJ and non-CAD XJ units use on both sides of the diff.

When deleting the CAD, the seal to install that works on the right side is a Napa 11800, which fits the ID of the right side axle tube and the OD of the axle shaft. You install it into the axle tube from inside the diff, similar to the left side. The problem with that seal is you have to stop at the correct depth, so that the seal lands on the seal surface of the axle shaft. Theoretically, if you kept on hammering, you could hammer that seal all the way down to the CAD. So you need to stop in the right spot. One positive, is that you can install as many seals as you like. Put in a second seal if you like, they will just stack up down the tube.

Also, that seal is just a simple flat oil seal, so it's not going to fit snugly into its perfect spot like the left side seal. So I would advise coating the outside face of the seal with a gear oil RTV.

Me personally, for the CAD axle, my personal choice is to perma lock the stock 2 piece axles together, so I can maintain the original design with the factory outer seal. I didn't like the way the 11800 seal installed. It was too difficult for me to check depth and get it correct. Just feels easier to me to keep it stock, lock the axles together for the same effect, and call it done. The 1995+ CAD axles use the newer stronger u-joints, and there is no loss in strength. Some people say the collar is weak, but they are using that exact same collar on the full time 4WD 392 JLs....so it's fine. Doesn't matter in this case anyways, though, as you have welded the CAD closed. So 11800 seal it is.

And to address the existing seal being different, that is because it is and it was added by the previous owner. It's either a sealsit or the 11800, but it doesn't look like I remember the 11800 looking. So could be the sealsit seal. The RTV was just to help it seal even further, and the orange stuff is stock from when they press in the tubes and has nothing to do with the seals.

 

[machoheadgames]

Learn something new everyday. Whats the difference between the CAD and non CAD seals?

Just posted a deeper explanation right as you posted this. The CAD axles need gear oil to the CAD area, so gear oil runs down the tube into the CAD box and then they seal the right side at the outer axle shaft.

Non-CAD axles have no use for gear oil in the tubes, so they seal both sides off at the pumpkin. Left side CAD seal is the exact same seal as all the fully live D30s use on both sides.

 

[lBasket]

Don't pick at the red. That's where they pressed the tube into the diff.

Inner seals should be the same. Likely you have one that was replaced at one point.

Whoops...

 

[tworley]

Whoops...

You'll be fine!

 

[machoheadgames]

Also, don't reuse ring gear bolts, and don't torque them to the ridiculously high torque spec in the FSM (70-90 ft lbs). Torque them to 55 ft lbs and use generous amounts of red loctite. Make sure to clean the oil off of them and out of the ring gear holes. If you reused them and/or torqued them to the high factory spec, I would seriously consider redoing them.

 

[Astala3]

I won't begin to start quoting everybody and their thoughts. No time now. I've got to finish this axle ASAP so I can get it under the jeep to then put the trussed 8.8 rear end under there also. gotta get that done to measure and order the new cv driveshaft. get the new driveshaft in there then drive it for 600 miles. all this before The Bantam Jeep Fest, June 13-15. I'm already registered and paid for that. did that intentionally so I don't drag my feet on this work.

Any way, after looking at those pics, I did come to the same conclusion that the red is from tube install. I am very thankful for the all the seal info. I did examine the seals in the CAD unit before closing it. I was something as described above. Though there wasn't really a standard looking proper seal on the outboard side of the CAD. on the inboard side was a seal looking something similar to the inner seal on diff end of the same tube. there was a small bit of oil in the CAD when I opened it. from what I remember the outter tube, from the CAD didn't look to be saturated with oil. maybe it was maybe just oily like a leak. I'll look again. though that's odd. perhaps what didnt look like a seal really is.

in the end, I either open the CAD back up to use the normal seal or use the unpleasant 11800 in the diff housing. or run it like it is and watch for evidence of a leak at the passenger steering knuckle. yeah, giving my serious time constraints, I'm gonna do that.

yes, I jumped the gun on the ring gear bolts. did a fast search and landed at 80lbs. the one that broke was number 4. I turned it down to 70 and finished them. then I searched for the proper bolt size only to discover there were 3/8 and 7/16 bolts used. 3/8 calls 55lbs and 7/16 calls 80lbs. oops. after speaking to my buddy who is a mechanic, I settled on a new bolt replacement bolt at 55lbs. I took questioned the integrity of the other 9. He advised I left them as they are. He's an old school redneck who loves his lifted old Chevy as much as did getting it in the mud holes. He touched plenty of differentials. He said he doesn't even toque them, "usually just tighten the piss out of them with locktite"!

ok. this keyboard is slowing me down! I'm out

 

[Astala3]

Non-CAD axles have no use for gear oil in the tubes, so they seal both sides off at the pumpkin. Left side CAD seal is the exact same seal as all the fully live D30s use on both sides.

Left side CAD seal? Left side is the diff side, the inner side. The side that would allow oil into the CAD. If I’m understanding everything, the. The right side, is the outter side, is the side that seals oil into from leaking through and out the shaft behind the knuckle.

I’m looking at it now. I was mistaken. The right side, or wheel side, does hold the seal. The left side, or diff side, hold the funny bit.

 

[Astala3]

Is that wheel side in the CAD the standard diff seal, the Spicer 46470? That’s the spicer I was sold for the inner seals anyway.

 

[Astala3]

Is that wheel side in the CAD the standard diff seal, the Spicer 46470? That’s the spicer I was sold for the inner seals anyway.

I guess I’m just gonna press and out and compare. It’s gotta come out anyway!

 

[machoheadgames]

Left side CAD seal? Left side is the diff side, the inner side. The side that would allow oil into the CAD. If I’m understanding everything, the. The right side, is the outter side, is the side that seals oil into from leaking through and out the shaft behind the knuckle.

I’m looking at it now. I was mistaken. The right side, or wheel side, does hold the seal. The left side, or diff side, hold the funny bit.

View attachment 618314

View attachment 618315

Sorry, that should have read “on the cad axle, the left side seal” talking about the seal for the left end of the whole axle assembly.

In the cad there is just one seal, at the far right. The piece on the left side of the CAD is a plastic bushing to support the stock intermediate axle shaft.

 

[machoheadgames]

Is that wheel side in the CAD the standard diff seal, the Spicer 46470? That’s the spicer I was sold for the inner seals anyway.

The seal in the CAD is 42500. The seal for the left axle shaft is 46470 and on non-CAD axles, they use 46470 on both sides of the diff. Aka any TJ Dana 30 has x2 46470.

 

[Astala3]

The seal in the CAD is 42500. The seal for the left axle shaft is 46470 and on non-CAD axles, they use 46470 on both sides of the diff. Aka any TJ axle has x2 46470.

Thanks bro. I really appreciate it the lightning fast reply’s. You rock!

 

[Astala3]

I just called every local parts dealer around. No 42500 locally. Had to hit Amazon and pay for one day delivery. Not terrible really just tuned and $11 seal into a $22 order.

Now I’m gonna put this top back on the CAD box and cut the face off. So I can continue the truss work now and throw that seal in tmw night. Huh, if I were a smarter man I would have ordered two, for Justin Case!

 

[machoheadgames]

Just to be clear, you don’t want the 42500 seal unless you are going to run a 2 piece axle shaft. The long TJ shaft is too narrow for the 42500 seal, and it doesn’t have a machined seal surface anyways.

 

[Astala3]

Just to be clear, you don’t want the 42500 seal unless you are going to run a 2 piece axle shaft. The long TJ shaft is too narrow for the 42500 seal, and it doesn’t have a machined seal surface anyways.

Well crap! What seal do I want? Will the 46470 fit in there?

 

[Astala3]

I don’t know how this front end ever held oil in!!! Haha

Here’s the 46470. Much better fit. This has to be it!

It’s going in!