• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

D30 disconnect to single piece axleshaft, seal questions

Awesome. I'm going to grab a shaft tomorrow ($33!) and try the installation on Sunday and the week following. It sucks when you only get a few hours of sunlight and semi-warmth (yeah right). Summer is definitely a better time for mechanical work.
 
Okay well I'm half way through the project. Ordered a napa 11800 seal and it'll be in tomorrow. Only thing now is that I have all the shafts removed except the inner-passenger shaft. It's held in by a c-clip. How do I get it off? Do I have to remove the center pin? And how do I do that?

Also will it be okay if I install the new shaft without the c-clip, since it can't have one?
 
Nevermind! I took a couple screwdrivers to each end of the c-clip, tapped a few times and the clip popped off, flew around the back of the case and came flying out and landed pretty much right in my lap - couldn't have gone more perfect! All shafts are out and I'm now going to take the carrier out and wait for the new seal.

Will the Napa seal fit in perfectly or will I have to grind the housing?
 
doesnt gear lube need to be in the disco housing? if yes, then wouldnt an inner seal not allow gear lube into the disco housing?

No. Lube was only there to start with to allow the collar to slide freely between both halves of the disco shaft. With a one piece shaft, you don't need lube out there since there are no sliding parts
 
Nevermind! I took a couple screwdrivers to each end of the c-clip, tapped a few times and the clip popped off, flew around the back of the case and came flying out and landed pretty much right in my lap - couldn't have gone more perfect! All shafts are out and I'm now going to take the carrier out and wait for the new seal.

Will the Napa seal fit in perfectly or will I have to grind the housing?

I have done 3 of them and the only problem I had was with the last one. The housing was from a 84 and the seal that I bought was a little small (NAPA CR11800). It went in easy with no grinding and now it is leaking a little. I have also done one conversion by replacing the factory seal at the disco housing and all I did was polish the shaft where is seals and no leaks, this one was done 2 yrs ago.

Good luck and post your results.
 
I have done 3 of them and the only problem I had was with the last one. The housing was from a 84 and the seal that I bought was a little small (NAPA CR11800). It went in easy with no grinding and now it is leaking a little. I have also done one conversion by replacing the factory seal at the disco housing and all I did was polish the shaft where is seals and no leaks, this one was done 2 yrs ago.

Good luck and post your results.

I put the 11800 in without any grinding. It squished the outside 'paint' off of the seal, as it was a little tight, but I don't think it'll be leaking! I surely hope not anyway. I did a test fit and it seems that the polished end of the shaft sticks out farther than the seal sits though, so I'm going to have to measure that to make sure.
 
Okay here's something I never heard anyone talk about before. On the outer side of the differential, but on the inner side of the shift collar housing, there is a roller-bearing. This bearing supports the inner-shaft when it's not locked together. I tried beating on it so it would pop out towards the housing but it wouldn't budge. I don't want to mess it up and make it so I have to take it out, either, but I also don't want to have it explode on me going down the freeway because it's not getting oiled.

Should I just get a big socket on it and a sledge, and pound it out? Who's dealt with it before?
 
Last edited:
Okay I managed to punch out the roller bearing out of the axle. It sits in a metal sleeve that seems part of the axle housing, so in the future if anyone decides to punch it out as well, make sure you hit the bearing and not the thickened part of the tube.
 
Last edited:
Okay I managed to punch out the roller bearing out of the axle. It sits in a metal sleeve that seems part of the axle housing, so in the future if anyone decides to punch it out as well, make sure you hit the bearing and not the thickened part of the tube.

I use a large brass punch or drift so I do not scar the housing. If you scar the housing the new race will hard to get in straight and may egg shape as well.
 
No. Lube was only there to start with to allow the collar to slide freely between both halves of the disco shaft. With a one piece shaft, you don't need lube out there since there are no sliding parts


the point i was trying to make was that, redneckboarder was saying that his disco30 had an inner seal. if it had an inner seal than how would the 2-piece shaft disco collar get lubricated if there was an inner seal in the diff housing? i realize that the one piece shaft doesnt need to be lubed and thats why there is an inner seal, but he was saying his disco30 had an inner seal.
 
The swap is done! And it works beautifully. Thanks for all the help, guys. Will check for leaks tomorrow. And..

(Cross posting from another forum)

I believe I have fixed my NP242 'bucking/banging' problem in 4x4. As I've said before, when in 4x4 and especially full-time, I would get a BANG now and then and one time it got so bad that I heard a BANG and then nothing but grinding sounds. I knew it wasn't popping out of gear because the lever never moved, and the 4x4 light's never changed or went out.

The problem? My front vacuum disconnect. During the time I swapped the NP242 in, I moved the shift fork over with washers and nuts to permenently engage the two-piece axle shaft. I suppose it was either grabbing or shifting enough under different torque loads to cause it to free up and case the bang and grinding sounds.

I spent the last few days tearing apart my front end and replacing the whole two-piece design with a simple one-piece shaft from the junkyard (off an '89 with an NP242 no less) and took it for a spin today. The results? Beautiful, beautiful full-time 4x4 with no more horrible banging sounds underneath. I drove for an hour and not ONCE did I get any odd noises. I took it up multiple hills, revved the crap out of it, cruised, etc, and couldn't get it to bang once. Problem hopefully solved!

TLDR: Front vacuum disconnect must have been screwing up. Replaced with single-piece shaft and all is well!

Winter is fun again!
 
So to clear things up, which one did we finally decide on? Seems like the Napa is a no go cause it leaks somewhat and is tight. The 471763 seems to be working for now and Eric recommended 470160. So which one will work better?

National #471763
National #470160
NAPA CR11800
 
You need to put a seal in the housing next to the diff, just like a non diso housing would have.

The National number for the seal you need is 470160. It will fit in the housing and the seal surface on the shaft.

Eric

so does this seal fit in the vacuum housing without taking a dremel to it? if so i will have to invest in it
 
Back
Top