My 1971 521

[datzenmike]

The fill and the drain bungs are interchangeable and differential bungs will also fit. I like to collect the ones with the magnets and use two of them. You or someone will have an old diff or trans laying around you can get one out of.

 

De-grease the old one, smear a small amount of RTV around the edge, insert into place. Get a 1/2 " ratchet extension and hold against the center of the bulge, hit hard with a small sledge. The plug will expand and lock into place, the RTV is insurance, probably don't need it. This is what I did on my 620 box.

[mainer311]

My guess is that it’s there so that you can remove it and have easier access to the lower bearing race for removal purposes.

[datzenmike]

Maybe for reaching inside to align bore and machine the surfaces for the bearing races.

[d.p]

No ducking idea.  But I do know it’s mangled enough that it won’t even seat for me to hammer it.  Metal is super soft too.  
 

I thought I had it right with RTV but it leaked and now here I am.  
 

 

[d.p]

This is what it supposed to look like. 

[datzenmike]

That's why it's so soft so it will expand.

 

Did you give a good smack in the center???

[d.p]

Yeah man but I think it just expanded too much now.  Not sure I can even get it back in at this point.  Have to figure something else out.  

[Charlie69]

Get a yoke from any Z car 280 back, any 720 truck even a 3 speed automatic yoke will work.  You are installing a 5 speed correct?

[d.p]

If I could round it somehow to bring the ends in I could maybe get it.  But no idea how to do that.  

[d.p]

Just now, Charlie69 said:

Get a yoke from any Z car 280 back, any 720 truck even a 3 speed automatic yoke will work.  You are installing a 5 speed correct?

Yes but this is the steering box not the transmission.  

[mainer311]

Try to re-cup it by putting the convex side into a big socket, and then pressing the concave side with a smaller socket. Stack it all up in a bench vise and see if it’ll reform itself.

[d.p]

Ty man. I’ll give it a shot tomorrow and see what I can do.  I also ordered 2 of the expansion plugs which I am pretty sure Nissan gave me the wrong ones when I got them from my local dealer last week. 
 

Found them on a forklift website no less:

 https://store.hgmforkliftparts.com/nissan_forklift_parts/NI00933-34000.aspx

 

 

[mklotz70]

I was going to suggest something similar to mainer311.  

[Charlie69]

4 hours ago, d.p said:

Yes but this is the steering box not the transmission.  

Sorry man I thoght you were working on the drive shaft.  Too mant days in Texas!  LOL

[d.p]

@mainer311 If I ever meet you in person I will buy you a beer. 

 

In the end best way to form it back was with a big socket, small freeze plug, smaller socket behind that, vice and some leverage.   I did have to smooth out the inside of where it seats in the gear box because someone prior to me drifted the sides in and that was making it almost impossible to seat it.    

 

 

 

It fits now but I didn't seal or hammer it home because I figured I would wait for the ones I ordered to show up to see what they look like.  I am also not sure how to best seal it, I did use RTV the first time on the back side but I didn't hammer it that hard, just got it seated and called it good but leaked right away.   I figure this time RTV, hammer, wait 24 hours and pray to the gods.  

 

 

[mklotz70]

Hard to tell if it's fully seated at the top of the pic.

 

[d.p]

11 minutes ago, mklotz70 said:

Hard to tell if it's fully seated at the top of the pic.

 

 

It should be but even if it isn't I can massage it a little more.  My fear is that its so mangled around the edges that it won't seal even with RTV.  

[Crashtd420]

2 minutes ago, d.p said:

 

It should be but even if it isn't I can massage it a little more.  My fear is that its so mangled around the edges that it won't seal even with RTV.  

Are you trying to seal that outer cover?

I thought there was something else behind that that looked like a freeze plug.... wouldn't that be the part that seals it?

 

[d.p]

Just now, Crashtd420 said:

Are you trying to seal that outer cover?

I thought there was something else behind that that looked like a freeze plug.... wouldn't that be the part that seals it?

 

 

yeah and that is all that sits between the bottom bearing/race/worm gear.  Unless I am missing something?

 

 

 

[Crashtd420]

2 minutes ago, d.p said:

 

yeah and that is all that sits between the bottom bearing/race/worm gear.  Unless I am missing something?

 

 

 

 

Ok , I thought you mentioned trying to fit a freeze plug.....

One thing I see in the picture are the hammer marks on the steering box....

Maybe clean those up so you have a nice round diameter to fit the cap....

[d.p]

I did clean them up with a brass punch and hammer but is there a better way?

[mainer311]

1 hour ago, d.p said:

@mainer311 If I ever meet you in person I will buy you a beer. 

 

 

I'm just a backwoods hack, man.

[mainer311]

11 minutes ago, d.p said:

I did clean them up with a brass punch and hammer but is there a better way?

 

That's where the cap was staked originally. File them off. If you want, after the cap is reinstalled, you can restake the edges with a pointed punch and large hammer. 

 

This is a gun part, but it gives you an idea:

[mklotz70]

 

 

[mklotz70]