trans assembly: gear bushing too tight?

[rsj]

Hi all. Am re-assembling the trans for my 69 Spider and have run into a snag. I installed new brass? bushings ("dimpled" inside) into 3 of the gears but none of them will slide easily onto the mainshaft. If I carefully press a gear/synchro assembly onto the mainshaft (say, 3rd gear), it simply starts to push out that bushing. I thought about freezing the mainshaft and heating the gear assembly in the oven, but would it make that much of a difference? On a spare mainshaft, an old gear assembly (with worn bushing) slides right on and spins, which I assume is what it is supposed to do? Does the new bushing need reaming or something?
Suggestions?

[Bill S]

Not sure why this one slipped by when you first posted last month but the answer to your question is yes, the new bushings need to be machined to fit the shaft. I can't find the spec in my gearbox manual but I seem to recall that you DON'T want less than .001" clearance or your gear may sieze on the shaft when it warms up. I've known a couple people who had to pull their proudly rebuilt transmissions for this reason. You may want to do a search rather than rely on my failing memory for the specs though.

[rsj]

Thanks Bill. The machinist has gone ahead in the absence of firm specs. and reamed/honed? it for .004-.005" clearance. He also noted that being too tight could lead to the gear seizing up. Thanks for the reply!