# Snapping/popping from differential



## sweetnsimple (Dec 14, 2005)

I've got a '94 Wrangler YJ with 2.5 L and auto trans, 2.5" Rancho lift kit (though it seems to sit higher than that), 16" Rock Crawler wheels and 245/75R-16 Goodyear MTRs all around. I'm pushing a Fisher Homesteader poly in the 6'8" size, have about 20 customers here in Northeast Ohio and have had about 10 snowfall "trigger events" since Thanksgiving, which comes out to some 200 driveways plowed during the past three weeks or so.

So far, no complaints about the Fisher or the YJ's 4-banger. Both have handled some wet, heavy lake-effect snow in the 3- to 6-inch range without showing any signs of strain or distress, until just the other day ....

Seems that most of the snow we received earlier was in the early AM, and I was out and working long before the city's snowplow/salt trucks had a chance to clear the roads. Also, I made some adjustments to the Homesteader's scrape-lock mechanism in order to get more downforce when back-blading. The net result of both developments is that I've started doing a lot more work on "dry" pavement during the past week or so than was the case earlier in the year. 

Some of you probably see this coming, but here it is all the same. Couple days ago while plowing in 4H, I hit a clear spot of pavement while making a hard left turn and generated a horrible crunching, popping, gear-gnashing sound from the front of the Jeep, most likely from the differential. Since then I've noticed some snapping sounds coming from this area when turning hard left on snow, shifting to reverse and accelerating, turning right on snow (though not as bad), and it happens in both 4H and 4L, but never in 2H.

On the day this first happened I checked the fluid level in the differential and found it to be a bit low and looking really foul. Also noticed some pooling around the seal of the left front wheel. I drained as much gear lube as possible with a suction gun and refilled with Lucas 85-140 heavy-duty fluid, topped off with some Lucas oil stabilizer to bump up the viscosity. That seems to have stopped the leaking from around the seal and modified the noises a bit, but not completely.

Know this is going long, but I'd rather get the details out now instead of in several threads, as we've got a mix of snow/ice/freezing rain headed our way and the weather people can't make up their minds on which combo we're likely to get. Question(s) are: What's making that nasty sound? How long before it starts to hurt performance (rascal still scoots along in 4H and 4L same as before) and/or do major damage to parts? And what's the fix, amount of time/money involved to make it right?


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## tessdad (Jan 25, 2005)

*Clunk-clunk*

My best guess would be your front axle universal joints. Jack up the front end, with it in 2wd, rotate the tires, inspect the u-joints, listen for clunking, be aware of any roughness or stiffness while turning the tire. If they are original, they may not have grease fittings, if they have been replaced they might have. If this is the source of your noise you need to do something about it soon (now) before they fail completely.


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## sweetnsimple (Dec 14, 2005)

*Thank ya!*

Appreciate that advice. Dropped the plow yesterday and crawled around underneath the front end looking for problems. Didn't jack the front end and listen for noises, but did grease the hell out of every zerk on the front end. Didn't see and haven't noticed any grease points on the U-joints, so chances are everything's original.

Turns out the rain/snow/ice mix the weather folk couldn't decide on is coming down snow, and pretty damn hard as well. I'm gonna have to go, possible bad joints and all, since there's no way I'll get a fix in b/4 we hit our trigger. Will jack and listen for clunking when I get done, if the problem itself doesn't make that unnecessary before then.

Thanks again.


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## sweetnsimple (Dec 14, 2005)

*Tessdad nailed it*

Thanks, TD. The local 4Wheel Parts store had the front axle U-joints in stock for about $25 each, and after consulting some other websites and getting confirmation from the 4Wheel guys that the existing joints were indeed shot, I went ahead and had them install 'em and the clicking, popping and gnashing are now gone.

Guess it doesn't matter how many responses you get when the one and only received nails it. Many thanks.


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