A CAT $631G$ single engine scraper is hauling an earth and gravel mixture which weighs $2,600lbs$ per lcy$.$ The struck capacity of the scraper is $24lcy$ and the heaped capacity is $34$ lcy$.$ The empty scraper weighs $105,002$ lbs$.$ The scraper's rated load is $81,600$ pounds. The loaded scraper is climbing a $8\%$ grade and the tire penetration is $2$ inches. The weight distribution when loaded is $52\%$ to the drive wheels and $48\%$ to the rear wheels. The coefficient of traction is $0\mathrm{.}45.$ Compute the required rimpull and the usable rimpull in pounds. Is the coefficient of traction sufficient? Explain your answer.