I need some help with my 1987 5 speed 4x4 trans, it sounds like it has square balls in the bearing! it makes a loud grouling sound in all gears including reverse, it will also make noise in neutral with the clutch out. I think it is the input shaft front bearing as it would not make noise in neutral if it were any other bearing, but that is just me thinking. My question is, what if any are the common failure items with this trans, my other question is I have another 5 speed trans from a 1985 celica, thats where I got the engine from to get this truck on the road. Can I change the tail housing to the 4X4 setup and use it or is there some other difference that I cannot see with a side by side comparison. My last question is what transmission is in this truck, my manual lists 6 different models but only lists W56 model in a few sections when it refers to the 4x4, do I have a W56? Finally, how difficult is it to change the input shaft bearing?