904 mainshafts, Anyone interested in repros? Options

[Dr Evil]

I am checking interest in repro 904 main shafts. I think I can get them either made or made out of 901 shafts for much less than the $1800-2000 that they are commanding now.

[ME733]

... (IMG:style_emoticons/default/popcorn[1].gif) ...Racer chris, Dr. Evil., Jp stein,R towel,Brant,and others....This is a very intresting Post I hope it continues into some detail ..such as what gears/ ratios would be suitable ...for...street use...autocrossing...and road racing/ D.E. track days......there are plenty of gear charts available (thanks Dr,evil) and others...but as J.P.Stein pointed out, FINDING some of the gears can be difficult/impossable. From experience I am not a fan of aftermarket gears. they are usually not properly HEAT TREATED to about 58/59 on the rockwell "c" scale. I had numerious "reproductions" break.(not 901 transmissions). I WOULD LIKE TO PURCHASE A LARGE SIZE (poster size) 901 914 transmission blueprint/ diagram, or something of quality/ detail that could be blown up. From what LITTLE I know about the existing possibilities for regearing , removing and welding on a different 2nd gear seems to be the most cost effective. It also seems to be a reliable way to go. However if a mainshaft were made / remachined which would allow interchangable 2nd / 3rd gears in 2nd gear position that may be a better option for some people. I think that both of you should be concerned about quality. welding on the mainshaft may aneal the shaft and gear. It may require rehardning to get back to O.E.M. specs. Making a new shaft will require a hardning process. both process will require quality control on strightness. I think what you guys want to do is great and needed. (IMG:style_emoticons/default/popcorn[1].gif)

[ChrisFoley]

I think that both of you should be concerned about quality. welding on the mainshaft may aneal the shaft and gear. It may require rehardning to get back to O.E.M. specs.

I'm way ahead-a ya... (IMG:style_emoticons/default/smile.gif)
I make sure that I am not heating the gear teeth or the shaft core enough to soften them. As I mentioned before, the material is prone to hot cracking when the gear is welded on - so going slowly, keeping heat input to a minimum, and making sure the weld endpoints are properly filled is of utmost importance.
I did repair and assembly welding for machine shops for years so I have plenty of experience with hard-to-weld alloys, highly restrained weld joints and precision build-up for re-machining. This stuff isn't that difficult, it just takes time. (IMG:style_emoticons/default/welder.gif)