SM420 help!
 

I have the SM420 out my 67 C20 to reseal it while doing my 292 swap. Well wouldn't you know my luck, when I opened it up I found a roll pin in the bottom of the case. The roll pin measures 1/8 by 1 inch.
Any help with where I should look. Where did this come from?

Re: SM420 help!
 

I would try to find an exploded view of the internals online.
I can check my 1967 chassis service manual.

Re: SM420 help!
 

I found this online.

http://kinzers.com/don/landcruiser/t...x300/sm420.pdf

I am subbed to see what you find out.

Re: SM420 help!
 

When I rebuilt my SM420 the only thing that resembled a roll pin was the small pin that held the reverse idler gear shaft in place, #57 in the exploded view in the pdf linked above. In order to remove the reverse idler gear shaft you have to drive that pin into the idler gear shaft (in the linked pdf above it is step 13 on the second page). It's possible an old one fell into the case during a rebuild in the past.

Re: SM420 help!
 

Is it a solid pin or a split pin. #57 is in the back of the case and cannot come out unless the whole shaft goes backwards, even then I don't think it can make its way into the main body. I'm thinking a needle bearing or a pin out of the shift tower

Re: SM420 help!
 

I would go by the function. Does it work correctly?
If it does I would just move on. I may be more pragmatic than some?

Re: SM420 help!
 

Well I'm convinced it doesn't come from the transmission at all. Even though the diagram calls out 4 roll pins none of them are actually roll pins they are all solid pins. This is a roll pin as I stated.
Now there is a roll pin in the shifter assembly, however that pin can't be accessed with the shifter in the transmission. Also that pin is in place. How this got in the transmission I have no clue. I'm moving on.

Re: SM420 help!
 

With such a reliable transmission I'd do the same, tried and true.

Re: SM420 help!
 

It is common to use a roll pin to replace worn shifter guide lugs on the top of the trans. My guess someone dropped one down through the shifter opening. Other than that, there are roll pins that retain the 3-4 and 1-2 shifter yokes to the shifter shafts on the top loader.

Re: SM420 help!
 

The pins for the shift forks are solid pins. The lugs for the shifter are larger in diameter. Try again

Re: SM420 help!
 

Try again seems a little smug on your response. I have rebuilt over a dozen of these transmissions in the last year, On occasion, not very often I'll see a spring pin in where originally they were solid pins OEM. If someone was in there in the last 50 years it could of been replaced with a spring pin, fell out of the yoke and found the magnet on the bottom of the case. The second guy could of correctly replaced it with a solid pin and that would be an example of your situation. Believe me I seen some really shoddy workmanship in these transmission done by individuals that should of never removed the top loader in the first place.

Re: SM420 help!
 

Well when a respondent(you in this case) doesn't appear to have read the original post it tends to tick me off. I stated the size of the roll pin I found 1/8x1. You talk about shifter lugs that measure 5/16×3/4 not even close to the same size. If you have rebuilt a dozen in the last year you'd know that

Re: SM420 help!
 

I looked in the 67 Service chassis Manuel I have.
I could not find any better info than I send in the last link I sent.

Maybe 68panelman can find something in his Manuel.

Re: SM420 help!
 

My manual is 10-60 series, probably same as yours. I also have a 70-80 but obviously no SM420's there. Same info as you. Actually didn't even show a 420?, Only 3 speed, 435, and Clark 5 speeds.

Re: SM420 help!
 

Oh, I am so sorry for this, I'll try and do better next time.