Gm Sm420 Vs Condiesel (gama Goat) Sm420

Thanks, I'll keep that in mind. I've been emailing someone at Novak, and from what he can figure out, the only problem he foresees is the 3-4 shifter fork. Apparently there two models, a 591495 and a 3787258. Since I haven't dug into a SM420, I haven't the slightest idea if I can swap parts around. If I can swap parts, I'm hoping that I can use the shift forks from the ConDiesel on the "new" top cover. I need to look into this some more. Have any insight on that?

 

No, but if you want my opinion...you could waste a bunch of time and money trying to make this work. Stick with the tried and true would be my vote. They are not that hard to find.

 

Now I want a Gamma Goat! Those things are kinda cool, like a Sherp. That pic of them piled up for scrap ...

 

Okay. I found an early 420 for $75 back home that I might have my dad pick up. If I didn't make it clear, my idea was to try the normal top cover off of this transmission. If that top cover had the wrong shift fork, then I could try to switch the shift fork out with the ConDiesel shift fork. Then I would have the correct-size fork on the normal stick-shift top cover. That's the idea anyways.

I'm having a few text-based conversations at once, and I may have gotten ahead of myself with this one and not properly explained my current situation and plan.

 

personally, i've always thought the goat shifter could be cool for a cabover or something where you need to be able to shift the transmission remotely, maybe a rear engine bus? i'd absolutely think it's worth getting a NOS one though, ive seen both and the goat version seems to be beefier. of course, the gm truck ones are plenty durable, but the goat ones are yet another step up. if you do get the goat transmission, i'd happily buy the top cover off of it.

 

I'll keep that in mind. I'll check and see if the Gama Goat top cover works with a normal SM420 as well. One thing to note is that the NOS ConDiesel cover doesn't have the arms/brackets that go on the shifter....rails? Pivots? Whatever they are, the arms are not on the rails, so those would have to be found or made. I'll get some pics out on my 4-speed swap thread once I lay hands and eyes on the transmission.
http://www.earlycj5.com/xf_cj5/index.php?threads/160708/

 

I'm gonna double up on this statement. Novak has not confirmed or denied the heavier gears work with there shaft. Last thing you need is to have transmission issues after the conversion.

 

Alright, after alot of debating, talking to the seller, and staring at pictures, I've decided to do the big stupid and buy it. This is either going to work great or completely bite me in the rear and kill the project. We'll see. Either way I'll learn something, and I'll share what I learn here.

Can I ask the mods to move this thread to builds and fabricators forum?
I'm going to take some time and do a thorough comparison of the ConDiesel SM420 vs a civilian SM420, and I'll post my findings here. Hopefully someone will find this useful some day.

 

Dad picked 'em up for me today. Here's a new question I have: The inside of the case is painted or coated in yellow. Is that something I have to remove? Is it a coating put in there for storage, or is it actually painted?

I can't lay hands and eyes on it right now, but my Dad says it looks like paint to him.

Here's some pics:

 

Zinc Chromate? https://en.wikipedia.org/wiki/Zinc_chromate

 

Could be...
I'll look Zinc Chromate's uses some more. In the mean time, I guess I'll avoid eating it.

 

I don’t have the answer but your dad is a total enabler. Right on.

 

can you get some pics of the bearing retainer front and rear? Also the shifter top. This is cool.

 

Yep. I’m going to try and get as much info as I can (measurements, pics, etc.) and post it here, since there is very little info available on these transmissions.

 

That transmission looks to have never been run at all good find if it doesn't have any issues with the new mainshaft and top cover.

 

Judging by an ebay listing a couple of pics online, it looks like there were some transmissions that went from the factory directly into crates and didn't come back out. I believe mine are the the same, and haven't ever been run.

The Novak kit is just a stub shaft, and the NOS transmissions are 10-spline output and the same as a normal SM420 according to the seller, so it should work. Fingers crossed.

The top cover is the biggest "will it work?" right now. I'm wondering if I can swap around the shift forks between the top covers, but Novak could neither confirm nor deny that it is possible, so that's a tossup too.

 

Here's some shots of the ConDiesel SM420. Let me know if you want more detailed photos. The rear bearing retainer is going to come off once I throw the Novak adapter on it, so I'll get some more pics of that.

 

Looks like it's got the heavy webs. You'll have some fun with the grinder. I need to grind more off mine to upgrade from the V6 U-joints to 1310s on my flatfender.

 

Interesting it has the mechanics style yoke. That is 1940 technology.

 

If you get yours done first, can you throw a pic of it up on your build thread so I can reference it? If you don't, I'll throw up a pic of how much I had to take off.

*EDIT*
Just remembered that you have an AA adapter, and I'm using a Novak adapter, so the amount of grinding required may not be the same.