I just picked up a good sm 420 at my favorite scrap yard yesterday for $10.:D I was looking it over and I see that it has a 10 spline 1 3/8" output shaft and the bolt pattern on the back looks just like my sm 465. Does a 205 bolt right on to this using the sm 465 adapters? I searched, but found suprisingly little info about the sm 420.

No the pattern is different. It looks like the SM465 pattern but is smaller and a little differntly shaped. My supposedly "good SM420 turned out to have a HUGE crack in the case, so I'm putting my three speed (no useable 2nd gear) SM420 back in this weekend. Wanna sell that 420? Novak's site has lotos of info on SM420's, pop the top and make sure it hasn't been full of water, that is the reason I have two cases in my garage that are cracked, confined water+Michigan winter=broken housing.

Originally posted by mudtruck44
I just picked up a good sm 420 at my favorite scrap yard yesterday for $10.:D

I don't even think the local scrapyards sell any part for 10 dollars:(

Are you sure it is a 420 and not a 465? I think the 420 has revers on the opposite side from the 465 (i.e. to the left of L and 1)

Sell the 420 to 4Bangler and buy a 465 if you want to use a 205.

Never heard of a 420 with a "married" case - heard of divorced case situations. If you want to use a 205 then find a 465 - really common combo. I have an adapter and drive sleeve around if ya need them.

Yeah, I am sure it is a 420. I have a 465 in my truck with a 205. I didn't buy the tranny because I need to use it, just because it was a sm 420 for $10. Aaron, it is in good shape for a tranny, no rust inside. Only been sitting in the yard less than a week. I guess I can sell it if you want it. I realize I bought it for $10 but its worth more than that so we can talk about it.

PS- This scrap yard also has 2 sm 465's, a T-19, and a np 435. They aren't compete or in good shape though (rusty gears).

Originally posted by mudtruck44
I have a 465 in my truck with a 205.

I know.

I've never heard of a married 420 either is why I asked.

Maybe it's out of a Gama Goat or something weird......

Originally posted by reddwarf


I know.

I've never heard of a married 420 either is why I asked.

Maybe it's out of a Gama Goat or something weird......

There was one 420 married tcase combo, but the tcase was a turd and it wasnt very common. I've seen 420's mated to almost evey tcase out there, so you can probably find an adapter in the aftermarket. Personally, Im swapping from 420 to 465 (and giving up the lower first gear) simply because then I can clock my tcase and run bigger ujoints, neither of which are very likely with the 420.