Sounds like yours went quick. One day the 3-Speed in my '66 GMC popped out of 3rd. Overtime time it would pop out a little more and a little more. It finally got to where I had to hold it in 3rd. Then I was fighting it to stay into 3rd, lol. Bad synchronizer. Put in another Trans and my misery was over.


'60-'72 Chev/GMC Fan
GMC 9500 Fan
Detroit Diesel Fan