I know there are kits out there to rebuild the SM420. Does anyone know of a book or website that can walk me through it? The more detail the better, I've never messed with a transmission.
Depending on who you order the kit from they should come with fairly good instructions. And most of the shop manual for the years that used the sm420 have pretty good info to.
Novaks, has all you need to. There are a couple different out fits. Several guys on here have rebuilt theirs, many their first try, myself included. Its not to big a deal, easy as transmissions go, I have been told. I and several others have had good results, go for it and good luck. Novaks has a good web site with lots of info.
Come on Tom, finish your story! If I was sitting across the table at the coffee shop I'd have a few questions for ya, like; Where did you get your parts from? Was it a kit or did you just order individual parts? How long did it take to get all the parts together? What kind of problems did you encounter during the rebuild? Did you need any special tools? Did you have, or use instructions, such as a book, a manual a single loose leaf sheet, an exploded view, a photo description, just info from threads here on the forum? Have you re-installed the transmission and how does it feel? Did you find any wear on the shifting forks, the gears? Does it feel any tighter or smoother when shifting with the new synchros and bearings? Does it run any quieter than before? Did you do it with the engine and cab all in tact or do you have the truck all tore down to a bare frame? Did you replace the clutch and TO brg while you were in there? Did ya do that huh, Did ya????
Excellent film booklet ya linked us to at tocmp Jim, I’ve never seen that one before, but that's the one I'm gonna have next to the camera on the bench when I tear into mine. I spose I'm gonna have to spend the rest of the morning downloading and printing it out. My thanks also to Shawn McLain & George Phillips. Do any of the vendors sell that booklet; I haven't run across it before. Looks like I'm gonna need to spend a little time in the machine shop making up some new "Special Tools". That's half the fun of these projects. The staking tool for the reverse idler bushings looks like it’s gonna be the toughest one to make. And it looks like one will need to buy a reamer or better yet, take the idler to a auto-machine shop to get it honed after staking the bushings in place. (Keep line boring in mind here). That’s probably the best choice; I learned that after spending a couple hundred bucks on reamers for the front spindles. A couple of things I find interesting, are the needle brg retainer, never saw one of those on the three-speed trans, I always just loaded the brgs with heavy fiber grease. Also they call for staking the front brg retainer nut but with today’s thread locker chems that are available, I think I’d clean the threads real good and use a dab of Locktite.
Are shifting forks available from anyone, they always show wear on the side shifters and can account for that slop ya feel in the shift lever.
God, I hope the replacement transmission parts are better made than most of the other reproduction parts I’ve gotten. I have to rework at least 80% of the repro parts that I buy.
Denny, I used a rebuild kit and everybody knows you always replace the clutch and t/o brg any time you have it apart, or atleast thats what my brother in law told me after I had it all back together. Of corse I did not and now I am just waiting for the clutch to act up. Dumb mistake on my part, not the first and probably not the last no doubt. Good thing I can see some humor in it or I would be in trouble, cause I seem to do that kind of thing more than I should. My truck had a brownie behind the sm420 and the brownie had busted parts and lots of damaged parts. As bad as it was in side I thought I had better have a look in the forward transmission to while I was at it. The 420 was in much better shape, no busted teeth or any pieces of parts down in the bottom or nothing. Everything looked pretty good in there, just replaced the bearings and one or two bushings and all new seals, Novaks had any parts I needed. Seems to shift fine and is alot less noices going on, I can actually hear my radio now :-)I use my truck weekly around town and its the newest vehicle I own, besides my 05 Harley - thats my daily transportation. I am always wondering if something is going to go boom, but so far its working fine.
Thanks Tom, I drove stuff like this i.e., late 40's and early 50's cars and trucks for years, and always made it to work. Of course I should mention, that was in the late 50's and early 60's. But there is a lot less to go wrong with them than todays vehicles. As long as ya can keep the earl in them they will run forever. Novacs seems to be the place. I've been looking at their site for a few months now. I'd like to go through the trans this winter. Have a good holiday Denny Graham Sandwich, IL
Hey all, Here are my videos I took during my SM420 rebuild. Long video, full overview: Clutch hub and clutch keys: Main shaft overview: Pressing on the clutch hub: Input shaft needle bearings:
I hope these help. This site has provided lots of helpful info for me, I wanted to contribute back. Thanks, Greg
Greg, thanks for posting these videos. I've been collecting info on a rebuild and have the filmstrip pdf and pics form Sstock. These should help me amass enough confidence to start my rebuild soon.
It's a small world, but I wouldn't want to paint it.
