Can anybody tell me the difference between a 89 and a 1990 gearbox? looking to buy a open primary and very hard to find one to suit 89 softail..all seem for later 90 plus bikes , well the bargains anyway.

 

I think the only differnce is the mainshaft.

 

As Ride My Evo said, the difference is the main shaft, 90 and later have a splined main shaft.

 

If you check out the parts catalogs, it is quite obvious that most of them aren't really sure when they changed. Harley loved to change stuff mid-year and use up old stashes of parts...so with an 89 you would need to open the primary and pull the clutch to see what you have. If you have a tapered mainshaft, keep an eye on ebay for a 91-up gear-set that someone changed out for a six speed.

 

All `89 models came from the factory with tapered shafts. However, unless you have owned the bike since new, or know for sure it has never been changed, your best bet is to have a look in there as Tom says.