I’m rebuilding a customer’s gearbox, and I need to find a set of synchronizer cones, as well as a second gear. In a perfect world, I’d be looking for a third gear, or clutch gear as well. Also, the service manual says something about “energizing springs” and slipping them off over the clutch teeth. I assume they’re referring to something in the 2nd/3rd gear clutch on the mainshaft, but I’m not seeing anything in this gearbox like that, and there’s no picture of them anywhere. I didn’t see them in the exploded diagram in the Chevs of the forties catalog, either.
Hi Reid, I rebuilt my ‘41 transmission a few years ago. I actually sourced two donor transmissions, rebuilt one and have my original transmission on the shelf. I sold my second donor transmission. Look on YouTube for a guy named Jayhawker. He has a few videos on tearing down/rebuilding these transmissions. He’s a great resource.
Not in that terminology. This isn’t my first gearbox rebuild by far, this is my first 1941 Chevy 3 speed gearbox rebuild with a shop manual in front of me. Are they just referring to the rings around the gears that provide engagement feel, and gear retention? Nobody knows everything. Go easy on a feller. I used to specialize in European sports cars and exotics, so the nomenclature in a prewar Chevy might be a little bit different that what I know. Everybody’s allowed to learn. I’m also rebuilding a gearbox that jumped out of second and third gears, and was “rebuilt” last month by a guy that only changed out the bearings, and small parts. He didn’t even get it back together correctly, couldn’t put the side cover back on it, and it wouldn’t shift gears. I inherited an 81 year old pile of parts that may be missing things.
Last edited by TheIronSausage; 01/14/2301:41 PM. Reason: Attempting to validate my lack of knowledge about ridiculous terminology and semantics.
If anybody would like to help a brother out, and tell me what the energizing springs are, and where I can find them (or where they’re supposed to be) I’d appreciate it. I like doing things right the first time. If something’s missing in here, I’d like to source it before the unit gets installed, fails, and I have to warranty my work. Again, there’s no reference to them in either the factory service manual diagrams, or the chevs of the forties exploded diagrams.
The enersizing springs fit in a grove about1/8" wide.The go around the gear or shaft and are split. They come with a new 2nd speed gear actual denensions are 1 5/16 id. 1 3/8 0d, 3 7/64 thick. ronded on the eterior. Thhey also come with either the main drive gear or the main shaft.The are used to click into the lugs on the syncro. drom and keep the gears kind of stuck in place. they seem to never wear, can be roatated on gear to find an new spot and tension could be increased if necessary. They do help to keep the gear from disengaging.
In a booklet I have for three speed transmission repair it shows one on the "clutch gear" and "second speed gear". The photo shows one being pried off using the blade of a pocket knife. Wording under the photo : NOTE: In cases of improper shifting or gear clashing , check the synchronizer energizing springs on the clutch gear and second speed gear. If damaged replace springs, using a thin blade for a tool. " This is a reproduction booklet and the photo is lousy at best so I can not copy. My 29-55 parts manual list the energizer springs (GRP 4.413) and a retainer (GRP 4.381). Could not find an illustration of the energizing spring but it is listed as part number 591288 (1-5/16IDx1-3/8 OD x7/64 thick. Hope this helps.
Last edited by m006840; 01/14/2310:14 PM. Reason: Gene types faster than me!!
Awesome. Thanks for the help. They’ve got a flat spot in them? I don’t see a division in what I think you’re talking about on the gears in this box, but they look like a round ring about a third of the way up the second and third gear cogs, right? If so, these seem to be fine, but the second gear teeth are just wasted, and the third gear (or clutch gear) teeth have only seen engagement about halfway up, if not less. They’re nowhere near as bad, but while I’m in here, I probably should find a new one for piece of mind.
I am going to try and post a link of an online GM manual. It is the 38 Chev shop manual but it shows the operation of the synchronizer and the energizing springs. Although the transmission is a little different I think the synchronizing is very similar.