Yep, looks like he's correct Woody. I'm surprised that we didn't hear from one of our transmission experts on this one. I just naturally thought from past experience with 3speed syncro clutch or syncro drum that the syncro rings would be in a kit. I probably sold 3 or 4 of them a week for the 3 speed trans back in the 60's. The hot rodders were notoriously hard on syncros. Your problem is still in the 2nd speed syncro path somewhere and there must be a way of servicing it.
From what I can make out in the service manual the second speed syncro cone is machined/ground into one side of the 1st & rev slider. Hard to tell what ya got without having it out on the bench to actually look at it. Apparently there is no brass insert in the 1st & rev slider side of the syncro.
The second speed syncro ring looks like the most likely culprit. I would think that there has to be some brass in the path somewhere, but I can't tell by looking at the manual whether it’s brass or has a brass insert in it. I’d be surprised if it were steel to steel but it might be.
Unless someone in the know who's rebuilt one speaks up about the only way we are gonna know is to tear into it and find out what's what.
I haven't been into my 420 yet cuz she's a shiftin' just fine. But I'm gonna do the bearing, bushing, syncro, seal thing in the near future just so I won't have to worry if'n I'm out on the road hundreds of miles from home, like maybe in Raleigh or someplace like that.
I have a spare SM420 in the corner but I have too many projects started already, I just can't start another one like tearing into that trans, till I finish some stuff up.
Good discussion, lots of info coming out of it. Let us know what Novak has to say.
Denny Graham
Sandwich, IL
