Sm 465

[evan396]

1966 k20.Going to clean up the sm465 tranny and probably change the input and output bearings and then paint. Just wondering how hard they are to change. Also would like to know if the foam ring on top is original from the factory and does anyone make a replacement . We would think that it's there to seal against the tranny hump to keep the water and dirt out. Thanks

[57taskforce]

They aren’t bad to do. Make sure you’ve got it shifted part way into reverse before you try to take the top cover off. If not the cover won’t come off without breaking stuff. My build thread in my signature has a few pictures from when I did mine. You’ll need a good set of lock ring (not snap ring) pliers and a press and bearing knife/pullers are helpful. It’s not a bad job just takes a little time to get it done right. I bought my complete parts kit from eBay for around $100. I also had to buy the gear bushings as mine were worn. There’s a few good write ups on the net and videos on youtube that will help.

[evan396]

Thanks, do you happen to know anything about the foam?

[kwmech]

That is not a 465, looks more like a 420

[Killer Bee]

I'm sure better replies will follow but I'll take a stab at some of your questions..

that foam blob around the shifter is a floor seal to insulate the floor opening under the shifter boot.. this may have been OE on certain trim levels, a/c equipped, etc..

1967-72 Truck Foam Shifter to Floor Seal
This seal goes around the shifter base, between the transmission and floor board. This is for trucks that have the shifter mounted on top of the transmission (SM465, SM420). The approximate dimensions are 5 1/2" x 4" x 2" thick.

https://www.4speedconversions.com/tr...am_seal_1.html



although it may also protect the shifter seal to some degree, you can toss it, certainly not what completely seals the inside of the transmission case.. there's a bellows seal and ball socket retainer arrangement that takes care of that

https://www.novak-adapt.com/catalog/...s/sm465-parts/



as for the transmission model, I believe the the sm420 was OE in GM light trucks thru '66 and sm465 '67 and up if that helps identify yours if you know what it was removed from.. otherwise although I've pulled a few of them, two in and out swaps in one day once, but couldn't tell by that greasy glance which you have

lots of good info out there, good luck!

[1976gmc20]

I think the 465 has the PTO plate on the passenger side.

I know the 420 has the PTO plate on the driver side, because I added a PTO to my 1965 C50 to run the log loader hydraulic pump.

[Killer Bee]

^ good point, I thought I remembered my 74 having them on both sides but wasn't sure so I went outside and looked at my 71

here are greasier pictures than the op's of my 71 sm465 with pto covers on both sides..





65 sm420 right side only, no cover.. not crawling over the gravel to get the driver's side

[evan396]

Sorry guys, it's out of our 66 k20 so it is probably a 420. Got to get it cleaned up this weekend. Are these any different to change the bearings compared to the 465. And I am wondering if I can stack two of the foam seals for the 67 trucks.

[kwmech]

What ever you have room for and as long it doesn't interfere with the shifting

[evan396]

Well, we got it all cleaned up and painted. Just waiting on a gasket and seal kit and the top shifter seal. Bearing seemed tight with no shaft play. Synchros looked good to.

[mongocanfly]

Trans looks great!!

[1976gmc20]

I always liked the 420 better than the 465. They just seemed to shift nicer. Maybe that was just because they all had a couple hundred thousand miles on them and were getting nicely broken in.

[57taskforce]

Originally Posted by evan396

Well, we got it all cleaned up and painted. Just waiting on a gasket and seal kit and the top shifter seal. Bearing seemed tight with no shaft play. Synchros looked good to.Attachment 2001505

Nice work, looks beautiful!