I wish I had more time to race, might have figured this out by now. When I first start up my XT8 it sounds great, I pre-heat my motors with the competition heater, and runs like a champ, but about 5 min. into a race it gets this grinding noise, someone told me about it at the finals last Nov. and mentioned it sounded like a center diff. going bad, stripped it down and nothing looked bad. I talked with a couple of other Xray guys and they suggested it might be mesh in the diff housings, I think it was Brahnam ( i sure hope i spelled your name right) gave me a couple of the shims for the front and rear diff. noone ever made mention of the noise. Sure enough, the next race i attened in garland tx the noise was back, checked all gear meshes and stripped down the center diff. nothing appeared to be wrong. then it occured it might be my clutch bell shims, made no difference, when my truggy warms up, I mean like the diffs warm and the chassis warms up after racing. To make a long story longer, when i was tearing it down for the periodic cleaning, I noticed the gasket on the pipe/header was bad and leaking alot, just a nice lil hole facing the engine, could this be what is making what would sounds like a gear noise? I have yet to take it out on the track to test, but other than gear meshes, diff issues or clutch bell shimming; I can't think of anything else.
