Axle issuses

Hey folks, fairly new to this, but im in the mist of some axle issues, my rig is a 98 xj sport,4L with 231 tc 4.5 RC (short arm) lift chrysler 8.25 in rear hp d30 in the front 3:55 gears, running 31`s, no further mods as of yet. I thought for the longest time i had a bad pinion bearing in the d30, it sounds like rotational metal grind, that seems to be grinding its hardest when i decelerate, high pitched grinding when at speeds 30 and higher.. there is no play up and down at the yoke but rotational play bout half an inch or so.. so if im thinking instead of rebuilding the whole diff shouldnt i get a axle from a used parts store for $200, i have a mechanic doing the work so im trying to get away as cheap as possible as money is hard to come by these days! also, i need an opinion on weather or not i should regear to 4:10`s? thanks in advance for the help!

pull the front drive shaft out and go for a drive to see if the noise goes away, it could be anything from a worn double cardan joint in the shaft to a bad hub bearing. to check the hub bearings jack up the front axle so the wheels are off the ground and spin them by hand. if the hub is grinding you will most likely be able to feel it with your hands.

it is also quite easy to pop the diff cover off and take a look inside, if the oil that comes out is pearlescent there is ground metal in it from a bad bearing. placing a large screw driver under the ring gear and prying against the case you shouldn't be able to move it at all up and down, if there is play that is another indicator of a bad bearing.

it's far too easy to get a big fat bill from a repair shop when you drop things off and have no idea what is wrong. good luck.

Thanks grimm for the advice much appreciated! whats your opinion on regearing to 4:10`s with 31`s? keep in mind its my DD and see`s the highway atleast 2-3 times a week. i also use it to tow my 15` boat...

i would leave it alone, 31s with 3.55s is not bad at all. save the money for when you get the itch to go bigger and regear then.