89cherokeelimited

Ok so after troubleshooting with my rear axle I was told if my detroit locker was broke it would not go into pos traction. Well it goes in and it does awesome offroad... while i'm hitting the gas doing 20MPH or over it makes loud noises... when i let off the gas while it is coasting the noise stops till I hit the gas again. Could this be from bearings going out? What I thought was weird though is it makes noise while driving but not while coasting... this has me clueless. I want to go Dana 44 with lockers but that's like a ton of money lol

4.3L XJ

What kind of noise. Growling, squealing?

xjbones

maybe u-joints? did you put it in the air and listen to it?

89cherokeelimited

Like a loud humming noise. It doesn't grind much now it used to grind when I let off the gas and when I hit the gas while coasting. After I went offroading yesterday it drives better but still makes a loud humming noise while driving over like 20 MPH. I was thinking the u-joints cause I looked at them yesterday and they were rusted lol I think I need to replace the front diff to because when I locked 4x4 in in made a "CLUNK" noise. Not real hard or real hard jerk but it made a small sound. but the noise is my big concern really loud noise. I'm gonna try to drive it and have my friend drive beside me and record it on video and try to post it on youtube or something and see if someone can tell what the noise is.

I prolly need to try to lift the rear end up and try to hit the gas...

CrawlnCoupe

your front end might be the u-joints in the axleshafts too, mine use to make a clunking noise, when i did my lift i found one of my u-joints was completely shot so i replaced them both. now i can hear just a small clunk when the t-case engages and thats it. also you might wanna jack the rearend of the truck up and spin one tire, if the other tire spins the same way your locker is working if it spins the other way something is a miss. also pulling the cover and taking a couple pics might help us answer your questions as well.

4.3L XJ

Just from your description, it sounds like worn gears or pinion bearings. One thing you can try that will quiet down a little is to get some black power punch. It contains nickel filings. Yep you heard that right. The idea is that if you have pits, even microscopic ones, the soft metal will get mashed into them and that will quiet down the noise. It is not a cure all, but it does work. I had a D35 in my wife's XJ that we eventually gave to her daughter that had a terrible growl in it. I put some of that with new oil and it quieted down to half the noise level.

89cherokeelimited

sweet thanks for the help i'll pull the front and rear apart tomorrow and and post pics of everything and see if we can figure it out.