The Stovebolt Site Forums The Shop Area Engine Shop 1951 pickup 3 speed synchro

A friend of mine in Europe has a 51 GMC with a 3 speed with worn synchros. His synchro is the one with the 2 lugs on it. I have several with the later 4 lugs. It seems to me that two of the lugs can be ground off and make the later ones work. I also remember updating some earlier transmissions 50 years ago, but I don't remember what all had to be replaced to go to the 4 lug synchdro. Has anyone worked on a pre 53 3 speed lately. I think they all had worn out synchros if they had any miles at all.

I think you may be right in the grinding off idea. I recall there was a way to make them work, but it was 1980 the last time I had one of these apart...
Jon

Grinding the two unnecessary lugs is not a problem.
If you have not read my Blog post on synchro problems, I think it would be a good idea.

Thanks for the link. I really don't have much experience with the old SM318. Our pickups back in those days all had a SM420 and I ran T85, T86 and T89 BW behind my Y-Blocks and they are synchronized more like the later Saginaw. Lots of my friends had SM318 and I helped them with them, but its still not like when you work on your own stuff and have to fork out the money at the end of the day. I am hoping to take the required parts over next time I go to Europe. He was thinking of sending the whole box, but that would be expensive. When I go first class, I can check 70 lb. bags, but I'm not sure if a SM318 in a duffel bag would fall under that.