I broke 2 prop shafts this year and over course lost 2 props . would like to up grade without breaking the bank. I was told to replace the lowers with xrs just wondering if I should replace the whole drive with the xr drive or just the lower would work . The uppers have fine up to now thanks for any help Mark

Sounds like you have hit underwater objects or someone is putting the lowers together wrong. Some buddies lost shaft/props on 2 different boats. Switched mechanics and never had another problem. IMO, the uppers usually fail first unless one of those senarios occurs.

I think it just age & hrs the last one I broke when I came out of the water and didn't get the trottles in time driver error