My 1971 521

[d.p]

Thanks @DanielC  any idea if a 510 filler plug is the same thread pitch as the 521? 

 

Saw mike posted part # 48060 U2000 and found people using these as well on 510s: https://www.mcmaster.com/9847K13/?SrchEntryWebPart_InpBox=%239847K13 which are 3/8 BPST.  

 

 

 

 

 

[datzenmike]

4 hours ago, d.p said:

Can someone tell me how to measure how much I need to shorten my driveshaft?  Like from where to where do I measure?

 

Stock 521 4 speed is just a c hair over 26" the 71B 4 and 5 speeds are 31.5" so the difference is just a c hair under 5.5" removed from the front drive shaft to allow it to fit.

[DanielC]

I believe 510's are metric, so I would not think so.  But if the steering box on a 510, and a 521 are thread the same, it could work.

Datzenmike just replied.   About the driveshaft.

 

Edited December 27, 2020 by DanielC

[d.p]

39 minutes ago, datzenmike said:

 

Stock 521 4 speed is just a c hair over 26" the 71B 4 and 5 speeds are 31.5" so the difference is just a c hair under 5.5" removed from the front drive shaft to allow it to fit.

 

Thanks man,,any idea on the steering gear filler plug replacement?  Do these have a slit in the bottom to allow them to vent?  

Edited December 27, 2020 by d.p

[datzenmike]

 Same one is also used on the 620 box.

 

No need for venting the steering box does not get hot enough.

 

 

The one in my 710 is also rubbery too and fits 510/610/B210/210/A10/S10/S110 and 810.  I don't know why car ones are a different part number. Also a different number doesn't always mean it won't fit.

 

[d.p]

So a 510 gear plug will fit a 521? 

19 minutes ago, datzenmike said:

 Same one is also used on the 620 box.

 

No need for venting the steering box does not get hot enough.

 

 

The one in my 710 is also rubbery too and fits 510/610/B210/210/A10/S10/S110 and 810.  I don't know why car ones are a different part number. Also a different number doesn't always mean it won't fit.

 

 

[datzenmike]

No where does it say that. It says the 620 used the same one. It also says the car ones are a different part number

[d.p]

Ahh fuck me 620 one seems to be NLA as well. 

 

I really just need the thread and pitch so I can get something else. 

[Crashtd420]

17 minutes ago, d.p said:

So a 510 gear plug will fit a 521? 

 

I'm 99% certain an npt plug fits it..... I have a spare steering column in the basement.... I can pull the plug out and verify the npt size you need....

Just give me a day... 

[d.p]

Thanks crash.  I bought a 3/8” NPT and it doesn’t thread but that’s all they had that looked like it might work.  

 

Edited December 27, 2020 by d.p

[d.p]

Stock vs 3/8 NPT:

 

 

[Crashtd420]

3 minutes ago, d.p said:

Stock vs 3/8 NPT:

 

 

Yup that's what I am using, just checked...

[d.p]

1 minute ago, Crashtd420 said:

Yup that's what I am using, just checked...

 

interesting, I wonder why it doesnt thread in all the way for me?  

Edited December 27, 2020 by d.p

[Crashtd420]

Oh it didnt thread.... then its bspt....

I think I chased the threads....

You can take the plate off and run a 3/8-18 npt tap into it...

[d.p]

Cant I just chase it without taking the plate off?  put some grease on the the tap to catch the shavings? 

Edited December 27, 2020 by d.p

[Crashtd420]

Just now, d.p said:

Cant I just chase it without taking the plate off?  put some grease on the the tap to catch the shavings?  I thought I want supposed to do that because of the worm gear and putting it back together.  

Ya you can do that too.... 

You wont disturb the worm gear only the adjuster....

The grease would be easier....

You don't make a lot of chips...

[d.p]

I went ahead and ordered a 3/8 BPST male plug from McMaster-Carr and if that doesn't work Ill chase it with 3/8-18 and use that nylon plug.  

 

Edited December 27, 2020 by d.p

[datzenmike]

D.P. I can't see any reason for a soft plug except that maybe because it can't be tightened at all and doesn't seal that well and might act as a vent.

[d.p]

Just now, datzenmike said:

D.P. I can't see any reason for a soft plug except that maybe it can't be tightened at all and doesn't seal that well and might act as a vent.

 

The bottom of my soft plug is cracked/split so I was just trying to replace it with something that isn't damaged.  

[mainer311]

Original plugs were plastic that softened over time from being exposed to petroleum. (Kinda like the factory natural rubber ball joint boots.)

 

Factory roaster steering box plug is a straight metric thread. I suppose the truck could be BSPT, but I doubt it. The plug you posted above doesn’t look tapered to me.

 

If you find a replacement plug that works, and it’s plastic, I would only install it hand tight.

Edited December 28, 2020 by mainer311

[d.p]

50 minutes ago, mainer311 said:

Original plugs were plastic that softened over time from being exposed to petroleum. (Kinda like the factory natural rubber ball joint boots.)

 

Factory roaster steering box plug is a straight metric thread. I suppose the truck could be BSPT, but I doubt it. The plug you posted above doesn’t look tapered to me.

 

If you find a replacement plug that works, and it’s plastic, I would only install it hand tight.

 

You're right it doesn't look tapered but again that 3/8" NTP only threads like 1 turn so I know its not 3/8" NPT and no one seems to know what size a 521 steering gear plug size is.  All I could find on the internet is for 510s and that is 3/8" BSPT.   Also when I was at ACE the stock plug threaded into a 1/2" compression nut with ease but there weren't any 1/2" NPT male plugs to be had. So maybe it is 1/2" NPT?  Will pick one up from HD tomorrow and find out.  

Edited December 28, 2020 by d.p

[thisismatt]

3/8" npt doesn't fit but you want to try 1/2" npt???

 

🤣

[d.p]

Just now, thisismatt said:

3/8" npt doesn't fit but you want to try 1/2" npt???

 

🤣

 

No I do not. 

[wayno]

Just flatten the broken end, use a hack saw or cutting wheel to slot it and put it in with a screw driver until you get a new one.

 

9 hours ago, d.p said:

Stock vs 3/8 NPT:

 

 

 

 

 

 

[d.p]

Welp 1 foot forward 2 steps back. 

 

Fucked up my steering box when I originally tried to take out the column to replace the firewall grommet and mistakenly thought it came out through the cab.  I guess I dislodged the end bearing and when I put it back together that bearing got wedged in-between the worm gear and the end of the steering box.  When I turned the wheel it blew/pushed out out the cap on the bottom and mangled the shit out of the bearing.  Stupid mistake and now I need to figure out how to fix it?  I assume I need a new steering box and can replace the bearing?  If not I guess I need an entire column and box?