I have a '89 suburban 4x4 that makes a horrible groaning noise in the front end. It gets louder or quieter depending on speed and load on the front wheels. It gets REALLY bad when I turn hard at slow speeds. I think it's either a bearing somewhere or the front axle u-joints. if more info would help let me know and I'll post more. My question is..... how do I tell what gear ratio and axle I have? I'm thinking of buying a used axle and putting that under there while I rebuild (or have rebuilt)this one... I'd like to keep it pretty much stock.... Unless of course someone has a better idea for a stronger axle that won't break the bank. Also how do I tell if the gears in it are good? when I changed the fluid (and friction modifier)it all looked good and there was no metal in the gear oil. Thanks in advance people!!!