I have recently changed my box due to the old one cruncing into just about every gear. First of all the 2 codes were diffrent so i did my research and found that the 2 codes both had the same drive and final drive ratios so i carried on to fit it. Well when it was first done everything was ok but after around 50 mile its started whining but still changes gear nice and smooth. It came from a accident damaged car and has been reconditioned along with the engine fron the accident damaged car not very long ago. Do people think the box could be damaged or maybe needs something adjusting?

It sounds like a straight cut box but i dont think it is lol

Any help appriciated cheers