Not clear on what your referrencing. Is the noise coming from the gear box, between the frame and the tranny (BGB)? This is the weak link in these old machines, and can be found on ebay almost every day. I keep a spare on the shelf all the time, but have yet to bust one. (I do have one growling a bit now) =]
You're going to need one from a like model. Brand (simplicity vs allis) makes no difference. Models such as those from a hydro or variable drive machine will have too long of a shaft for your drive pulley. Maybe put a want ad in the classifieds, and I will look around too. Someone here probably has a spare.
Need to determine if thats the issue though. Is there excessive play when you work the pulley by hand?
I will tear into it if need Thursday. Might take pulley and clutch off today when I get home just to make sure it isn't either. And yes it's the bgb I am very new to tractors so still got a lot to learn. I have search eBay but if I have to I'll rather have min rebuilt about how much does it cost to rebuild?
Oooo..not sure. Ive heard that if you can find a set of gears new, they are very pricey. The money spent on used gears makes it easier to just buy the whole box used. Thats hoping you dont need seals, etc. I would think a rebuild can get expensive. Swapping boxes seems the most popular option