NP218 - Speedometer Gear Installation Help

[mgFray]

The pin from the 90 degree adapter broke off in my speedometer gear. To diagnose everything I removed the Speedometer Adapter (TM 9-2320-280-24P-2 Figure 488 Part 19) and the gear (part 17). Verified the pin was broken off inside of the gear (17) and no way for me to get it out. So I'll have to order a new gear.

Transfer case is an NP218 - 261 gears according to the tag.

Reading the re-installation instructions from (TM 9-2320-280-20-2 Page 5-50) it says:

- Numbers on pinion adapter represent number stamped on driven gear. When installing adapter, numbers on adapter must match with numbers on transfer case housing.

I figured this would be obvious, but the more I look the less I believe I have any idea what I'm doing. So I'm looking for a clue.

There is a bit of a diagram, but for the life of me with the exhaust right there, I simply can't find the numbers of an indicator for alignment.

I did put it back into the hole and I rotated it clock-wise until it stopped turning then put the lock on it. Is this the right way to do it, or does someone have better guidance for me?

Everything else was straight forward, but I really don't know if what I did is going to cause internal damage or not. (I just need this to block the hole until I get the new gear I ordered, but when the new gear arrives that needs to get installed properly as well...)

Any help/suggestions/guidance would be appreciated! Thanks!

 

[mgFray]

Well, I finally figured it out. The markings were under some sort of undercoat that had been sprayed all over the transfer case.

On my particular transfer case, there were two markings embossed onto the casting, with an arrow to a circle. The arrow pointed the "26-31" mark to the circle.. lined that up and it worked.

For future reference the markings are on the TOP (not side like it looks like from the TM) where the gear adapter goes in. On mine they were up against the metal, not the part towards "outside".

I wish I had pictures, but I didn't have enough hands for the camera, flashlight and mirror.

So you absolutely have to have an inspection mirror to do this job! (and of course I smacked mine on the speedo adapter cracking it in the process..)

 

[GYs_M998]

It looks as though I am just a few days behind you because I came here looking for the answer to the same problem. I appreciate your following up on this thread. Just know You were immensely helpful to at least one person that may or may not be a window licker. Haha.

I will do my part in adding to the knowledge base by taking photos as I do this. (I have an endoscope that can save photos/video). Once I have them, I will post them here. Cheers.

 

[mgFray]

Here we go. This is what you want to look for.

 

[mgFray]

Unfortunately it still isn’t working for me. Everything is now repaired but it doesn’t appear the it’s spinning the cable.

does anyone know what might be wrong or need adjustment? I’ve got it lined up, and no spinning. I can take it out of the transfer case and spin it.

 

[Mogman]

Unfortunately it still isn’t working for me. Everything is now repaired but it doesn’t appear the it’s spinning the cable.

does anyone know what might be wrong or need adjustment? I’ve got it lined up, and no spinning. I can take it out of the transfer case and spin it.

The gear in the case on the output shaft might be toast.

 

[mgFray]

The gear in the case on the output shaft might be toast.

That is exactly what I'm afraid of. Using the mirror I can see a green worm gear with what looks like clear teeth. But that doesn't mean it's working right..

 

[mgFray]

Ok, since I'm going to have to get into the transfer case and replace the driver gear (I think). I need to drain the fluids (which I need to do anyway). I've got a slight weap out of the drain plug already, so I know I need a new washer on the plug. But I've not been able to find either copper crush washers or rubber washers listed anywhere.

My NP218 doesn't have a "pipe plug", but has a bolt style plug with a washer under it.

Anyone have suggestions for what I need and/or where to get it? My usual sources have failed me.

 

[GYs_M998]

Ok, since I'm going to have to get into the transfer case and replace the driver gear (I think). I need to drain the fluids (which I need to do anyway). I've got a slight weap out of the drain plug already, so I know I need a new washer on the plug. But I've not been able to find either copper crush washers or rubber washers listed anywhere.

My NP218 doesn't have a "pipe plug", but has a bolt style plug with a washer under it.

Anyone have suggestions for what I need and/or where to get it? My usual sources have failed me.

I honestly just threw an o-ring on my drain and fill plugs. No issues.
As for replacing the gear (if necessary) you really only need to take off the yoke and tail housing to replace the gear. It’s not too bad.
Here is a link to a guy who tore down an NP218 to give you an idea of what you’re looking at. (1:50 of the video is where he pulls off the housing)
VIDEO

 

[mgFray]

ya, it doesn't look so bad.. just trying to get everything I'm going to need before I start the job.

I've got some o-rings so I guess I'll try that. I figured there was some standard washer for those drain/fill plug bolts... but so far I've not found anything except an ebay listing to buy 8 used bolts?!

 

[mgFray]

I just found this:

NV15054

It looks like it may be the same part with a new integrated rubber washer. (Of course the site I found it on went down as soon as I found it!)

 

[GYs_M998]

I found THIS SITE. It doesn’t give a measurement and it doesn’t specify NP218, but might be worth cross referencing to see if it’ll fit. I can imagine they used a ton of different sizes across their line of T-cases.

 

[mgFray]

Found them at a website called 'national drive train', and I ordered two (with shipping) for under $30. I'll let people know if they fit or not.

 

[GYs_M998]

Unfortunately it still isn’t working for me. Everything is now repaired but it doesn’t appear the it’s spinning the cable.

does anyone know what might be wrong or need adjustment? I’ve got it lined up, and no spinning. I can take it out of the transfer case and spin it.

Here are a couple pics from my endoscope. One is where mine was set before adjusting it. The second is where I finished. It matched what you set yours too. Mine also does not work and I KNOW my worm gear is good because it was working before I had taken the Speedo gear out and put it back in as part of a test. [it is my fault if the adapter was clocked to the wrong position in this instance, but I don’t think it was because I have an ORANGE 35 tooth gear].
The order of installing is to insert the gear into the adapter, place the keyed pin in top, attach the 90° elbow, then place the entire assembly into the t-case. Attach the cable last. I know this is slightly off from what the TM states, but I will be able to see that it is seated properly this way. I will use some transgel to hold the gear in while I insert it into the T-case even though the o-ring in there should hold it just fine. I am going to take mine apart and reassemble it. I am thinking mine was not fully seated and therefore not engaging.

I will report back with my findings tomorrow. Haha.

 

[GYs_M998]

I also found this picture. It confirms to me that there are no other markings. What we are seeing on our t-cases is all we get

 

[mgFray]

This definitely sets the gear offset. If it turns out the stamped marking is in the wrong place, that could certainly explain it not working.

Hopefully if you set it back to the originaly setting it will work for you. If it does, then I guess I'm going to have to try the same thing. I wish I had not missed the part in the manual about this, or I would have avoided taking it apart without finding a mirror. (Self-created problems....)

 

[GYs_M998]

ok... I have found the issue... There is another marking (see pictures). I assume that, like me, you have the orange 35 tooth speedo drive gear. if that is the case, you will see another marking on the opposite side of the orifice. now, that being said, I put mine to that setting and everything went smoothly. I got in to give it a quick test drive... problem. When I backup, the speedo runs as does the odometer. when I go forward, the speedo does not run and the odometer runs backwards (subtracting mileage). there are not enough walls to bang my head against. I guess progress is a good thing... though I just want it to work right. anyone have any suggestions?

 

[Mogman]

ok... I have found the issue... There is another marking (see pictures). I assume that, like me, you have the orange 35 tooth speedo drive gear. if that is the case, you will see another marking on the opposite side of the orifice. now, that being said, I put mine to that setting and everything went smoothly. I got in to give it a quick test drive... problem. When I backup, the speedo runs as does the odometer. when I go forward, the speedo does not run and the odometer runs backwards (subtracting mileage). there are not enough walls to bang my head against. I guess progress is a good thing... though I just want it to work right. anyone have any suggestions?View attachment 925050View attachment 925051View attachment 925052

Did you replace the 90 deg adapter that goes on the transfer case? that is the only thing I can think of that would "reverse" the cable direction.

 

[REF]

I don't see how you could get to the other side of the tail shaft with that gear to make it spin backwards. check your 90 deg adapter.

 

[GYs_M998]

I haven’t replaced any parts. Everything is the same. I agree that it makes absolutely zero sense.
With that said, I did partially disassemble and grease the 90° adapter. But there isn’t really anyway that could be put together incorrectly since it is also gear driven and has pockets for all the spinning parts to properly fit into. Seems like it would be pretty hard to assemble incorrectly.
I am really scratching my head on this one. Never seen anything like it.

—-
Ref, what should I be checking on the 90?