The Stovebolt Site Forums The Shop Area Driveline 318 shift shaft seals???

Anyone know a good source to buy the shifter shaft seals for a muncie 318/319 trans? I looked at mine (leaking a little) and i see absolutely no rubber lip of any sort. Ive looked around and have not seen any write ups on installing them to reference with pics or part numbers. Are they separately available or only in a “kit”? Thanks for the help.

The later side covers use an O ring on the shifter shaft. The side cover needs to be disassembled to replace them. I'm not sure when they made the change to the O ring, probably late 50's. Not sure of the size but it is common hardware. The early side covers used a seal which is located on the external casting protrusion that holds the shaft. The replacement seals I have located I bought by size at my local bearing supply. I presume it is a standard in the industry. If yours uses this type , I can provide you with the dimensions of the seal.
Fred

I have the ball detent style side cover if that makes any difference? Also...was the ball style or scissor style the preferred type for any reason? Meaning is one better than the other for say keeping it locked in gear?

They both work well providing the springs and other internal components are not worn out. The ball type is the early version. I find both types on the transmissions I rebuild.
Fred

I have access to both covers but i was wondering if one would hold a gear better. I already spun the energizer spring and shimmed the front bearing and it stays in 3rd 99% of the time but once in a while it will work its way out of gear. Ive had 2 different side covers on it but both were ball type detent. Mabey they found the scissor type was better so thats what was run on the later years? Im just brainstorming here.

You have done the common fixes to keep it in 3rd gear. The side cover is only one component and I'm not sure the scissor type is going to help in this situation. If the 2-3 shift fork is good then the only other variable is a worn 2-3 syncro assembly. Take a look at the large ring on the 3rd gear end, (where the shift fork rides) if it is worn excessively the syncro is toast. If it is OK then the problem is worn syncro rings or the nubs that engage the energizer spring.
Fred

I reinforced the crossmember I made and now its staying in gear 100% no problem. I guess it was flexing a little and it was just enough to pop it out of third. All good now.