Wes: I was driving my M-38 to a parade this weekend and I noticed that when I downshifted from 3rd to second gear, the tranny popped out of second. I notice that this happens to me occasionally when I drive at 30+ miles an hour. A friend of mine said it could be a worn poppet spring? What is your advice on this issue.
I rather go with the worn fork then the rebuild! I notice that it only happens when I'm downshifting and I may be going too fast for second gear, if that is possible in an M-38! I would think I have to pull off the shift lever housing to take a look.
There isn't a lot keeping her in second gear when using the gearbox to slow the jeep down and tthe loading against the synchro tends to favor popping out. So if either the shifting fork or the synchro's are worn she will pop out. So you have a 50/50 shot.
Wes: I was driving my M-38 to a parade this weekend and I noticed that when I downshifted from 3rd to second gear, the tranny popped out of second. I notice that this happens to me occasionally when I drive at 30+ miles an hour. A friend of mine said it could be a worn poppet spring? What is your advice on this issue. 
I rather go with the worn fork then the rebuild! I notice that it only happens when I'm downshifting and I may be going too fast for second gear, if that is possible in an M-38! I would think I have to pull off the shift lever housing to take a look.