It sounds maybe like syncros it's like the noise you get when your starting off on a real big hill and get that noise until you get out of lower rpm's , the guy that had the jeep before me was running 33x12.5x15 on stock 3.07's I have the 4.0 but would that matter I'm doing the front and rear ends come spring as well as re gearing to put my 33's back on, I downsized to 31x10.5x15's for now but because of all the stress could It have losened the syncros or someting else..... The clutch went within 3k of driving off the lot with it I got the dealer to replace that and the throwout bearing, could the mechanic have messed something up it's but it's been about 4-5k since the replace....