D30 Disco Elimination Axle Seal?

So I installed a Detroit Trutrac up front on my HP D30 axle along with chromoly 1 piece axle shafts (eliminating the disco axle shafts on my '87 XJ). I thought the correct seal would be in the kit I got to seal the pass. side axle shaft but it wasn't. And as most of you know the disco axles are not machined for a seal. I sanded the axle shaft and put a new seal in the stock disco location (near where the shift fork was). It lasted about 2 days and now I get some drips every now and then. I want to tear it all apart and reseal it properly (especially since I will be taking it to the sand in a couple of weeks). Anyone know the part numbers for the seal that I need? I did a search and came up with way to much contradicting info.

The numbers that I have been led to believe will work are:

Napa CR11800
Napa CR11343
National 471763

Can anyone verify this? I would like to have everything on hand so I can bang it out in a couple of hours without having the diff torn apart. Thanks.

Get the factory seal from a dealer or parts house (that a normal non disco housing would use).

Pull the carrier out.

Grind behind the carrier bearing until you can just barely install the seal by gently tapping it in with a hammer.

Reinstall, move on with life.



None of the conversion seals hold up. They don't have the little plastic ramp that centers the shaft when you are installing it, and you knock the spring off pushing the shaft in.

Hmm... for some reason I never even thought about modifying the housing, good idea, thank you.

Takes about 30 minutes with a dremel tool, plus R&R time on the carrier. Done once and never worry about it again.

drips might just leftover gear oil in the tube.

I recently found a new part number that works even better than the 11800. I think it was national 223050. Did two of these recently and they fit better than the CR 11800. I would have to double check the part number though I am going off the top of my head.

Yeah, but I thought the only proper way to do it was how Cal said since the only machined surface on the shaft that will ride properly on a seal is at the diff and not the disconnect. If I ever get to rotating my c's so I can switch to 760's, that's how I always planned on doing it.

you can run 760 shafts without rotating the Cs. I run the 223050 inner seal and 760 shafts on my comanche that I deleted the CAD on, seals great! I also run alloy outer seals to help catch anything else

I got a CR 11343 seal. It is slightly smaller than the factory right side seal. I think I will grind the tube down and install a factory seal AND the smaller one in the tube just for peace of mind.

Its not a huge leak but when I lift the left side on a rock while on the trail fluid will run out of the right side (I suspect it is a small leak and it pools up in the tube then pours out). Either way it bugs me, I don't like leaks.

BTW, the Trutrac is awesome up front!

Better not to double up the seals that way. The goal is not to keep the oil off of the ground, but keep it in the third member.

If the seal behind the carrier leaks, and then the oil gets trapped in the tube between the third member and the additional seal at the disco housing, you can run the diff dry and destroy it without ever seeing a leak.

cal said:

Better not to double up the seals that way. The goal is not to keep the oil off of the ground, but keep it in the third member.

If the seal behind the carrier leaks, and then the oil gets trapped in the tube between the third member and the additional seal at the disco housing, you can run the diff dry and destroy it without ever seeing a leak.

Click to expand...

I'm going to take out that seal by the disco thats in there currently that leaks. What I meant was to install one in the tube about .5" from the seal at the carrier (after I grind out the tube to install a stock seal). So both seals would be an inch from each other at the carrier...unless you think that would be a bad idea?

I actually do think that is a bad idea.

Its not necessary to begin with, the OEM seal is really really good. But the biggest thing is that the OEM seal has a plastic ramp on it that will center the shaft in the seal as you jam it down the tube, where the crappy conversions do not. The back side of either seal has a spring that holds the seal tight. Without that ramp, you can end up pushing the spring out of the conversion seal, and shoving it into your diff where it gets into your bearings, spider gears, etc.

Its not necessary to run a second seal, there's not any real upside to it, but a fair potential for it to go wrong.

take the bearing out of the CAD housing. I left mine in and it started making noise.

Bearing for disco shaft is out. Thanks.

I will just do what you said Cal, grind out the tube and install one factory seal. That is why I posted, to learn from people who know more than me so I don't screw it up. I will post an update once its done. Thanks for all the input.