have a 39 trans neesd main shaft and imput shaft. i have a closed drive side shift trans. Are the parts interchangable?
Yes, the gear sets for 39 - 48 are the same. The most important component to check with a mic is the caged roller bearing surface on the main shaft. If it is worn, then the whole main-shaft assembly wants to flex up and down and this is one of the issues that causes 2nd gear to pop out of place. If the 2nd gear bushing is worn, you might consider having a new one custom made (Charlie NY) - this is another important part of keeping these trans in 2nd gear.
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