Clicking / popping from front axle during sharp turns

[fuse]

There's a new noise coming from my front axle. It's started making a clicking/popping noise when I make a sharp turn at low speed, e.g. when parking. The noise can happen at very low speeds with very light load.

The obvious culprit would be a failing u-joint. To diagnose the problem, I took some GoPro video of it happening with shots of both front u-joints. I also checked the u-joints by spinning then by hand while steering to lock. That was all inconclusive. I didn't see any signs of binding or play in the u-joints.

However, in the GoPro video the clicking/popping sounds seem to be coming from the front diff. I have an open Dana 30 that last had a fluid change about a year ago.

The diagnostic guide in the FSM says that a low speed knock (which sounds about right) could either be a worn u-joint or worn spider gear thrust washers. So it could be the diff.

I'm about to crack open the diff to inspect it, but if it's just wear on the washers there may not be much to see.

It would be nice if I could figure out what needs repair before I order parts. Any suggestions on how to diagnose this?

 

[Steel City 06]

Personally, I would replace the u-joints and see if that solves the problem before digging into the carrier. New u-joints will cost you a few hours and $50; a new carrier will cost significantly more. Often, the u-joints don’t show any visible play until they are removed from the vehicle.

When you drain the oil, look for metal shavings. Excessive shavings may indicate abnormal wear. Typically, the shavings are small, much like a very fine glitter.

Less likely possibilities are ball joints, wheel bearings, and worn steering components. It may be worth replacing the ball joints while you have the shaft out if they haven’t been touched in a few years. Other (much less likely) possibilities include pinion bearing, driveshaft u-joints, and carrier bearings.

If you’ve thought about adding a locker and new chromoly shafts, this may be a very good time to do so

 

[fuse]

Thanks for the suggestions. This is a maintenance issue, not an upgrade opportunity, since I have other priorities for my money right now.

That's why I'm hoping to diagnose the problem further rather than replacing things that might still be in good shape.

Ball joints and steering components are all relatively new, so I don't suspect the issue is there. Also, the best evidence I have (from video) is that the sound comes from inside the front diff.

Any suggestions to isolate this problem?

 

[qslim]

FWIW I was having some steering noise similar to what you're describing last year. I jacked the front end, inspected everything but found zero freeplay in any of the components and was able to freely spin both front tires while I cycled the steering from lock to lock, unable to duplicate what I was hearing while driving. I said screw it ordered some new Spicers because the existing u-joints had the same patina of rust as everything around it, and when I popped the caps off the old joints they were pretty bad. The needle bearing were still there, but they were completely rusted and one side was almost completely dry.

Anyway I replaced them and the noise went away. Point is I wasn't able to pinpoint the bad u-joint with a external inspection.

I would also think it to be tough to isolate the sound to the diff with a GoPro.. When I fixed cars I used to have this contraption called Chassis Ears (I think) that had clips you could ziptie to various components and then listen while driving - it worked well because you could pinpoint noises coming directly from the component with very little ambient noise.

 

[fuse]

FWIW I was having some steering noise similar to what you're describing last year. I jacked the front end, inspected everything but found zero freeplay in any of the components and was able to freely spin both front tires while I cycled the steering from lock to lock, unable to duplicate what I was hearing while driving. I said screw it ordered some new Spicers because the existing u-joints had the same patina of rust as everything around it, and when I popped the caps off the old joints they were pretty bad. The needle bearing were still there, but they were completely rusted and one side was almost completely dry.

Anyway I replaced them and the noise went away. Point is I wasn't able to pinpoint the bad u-joint with a external inspection.

That's not what I was hoping for, but it's useful info. I may just go ahead with some experimental replacements to see if they help. Either new u-joints or new spider gears would be under $100. However, if I do the u-joints I'll probably take it to my mechanic because I have a habit of destroying press-fit parts.

I would also think it to be tough to isolate the sound to the diff with a GoPro.. When I fixed cars I used to have this contraption called Chassis Ears (I think) that had clips you could ziptie to various components and then listen while driving - it worked well because you could pinpoint noises coming directly from the component with very little ambient noise.

This is an interesting idea. I looked that tool up, and I'm not going to buy one just for this. But I might try rigging up an audio test with a Bluetooth headphone...

 

[Steel City 06]

U-joints on the front axle aren’t all that difficult. It can be done with a hammer and sockets or with a ball joint press. I prefer the latter but many users prefer the former. Driveshaft u-joints tend to be a little more tricky than axle shaft u-joints.

If you’re still concerned about breaking something, consider taking the axle shafts out and bringing them to a shop. That should save you an hour or more in labor charges.

 

[qslim]

That's not what I was hoping for, but it's useful info. I may just go ahead with some experimental replacements to see if they help. Either new u-joints or new spider gears would be under $100. However, if I do the u-joints I'll probably take it to my mechanic because I have a habit of destroying press-fit parts.

Yeah I destroyed my finger. Swinging for the fences with a 3lb hammer & missed. The feeling eventually came back and now it goes numb if the temp gets below 60. Lost my edge jockeying spreadsheets I guess. Good think it wasn't my mouse clicking finger.

This is an interesting idea. I looked that tool up, and I'm not going to buy one just for this. But I might try rigging up an audio test with a Bluetooth headphone...

Yeah that thing was really useful, dunno if maybe that's a loaner tool available somewhere or not - actually probably not because it isn't wireless and you had to tie the cable up carefully so you can drive around with it. I lost one to an axle once..

 

[AndyG]

Spray a quality lubricant on the U-joints and unit bearing... If they quieten down for a few feet then you're probably in the right direction.

 

[Brianj5600]

Do the joints seem to be seeping grease past the seals? I put my hand on the u-joint caps and twist the driveshaft back and forth. Usually I can feel slop if the joint is worn. Most u-joints I have had to change had oily looking seals. Disregard if the joints are greasable.

 

[fuse]

Spray a quality lubricant on the U-joints and unit bearing... If that quiet and sit down for a few feet then you're probably in the right direction.

I can easily try that. I have a wide selection of spray lubricants. What's a good "quality lubricant" for this test?

 

[AndyG]

I can easily try that. I have a wide selection of spray lubricants. What's a good "quality lubricant" for this test?

I like a product Lowe's sells called "slick stuff" , but anything thin and slick will work , even wd 40.

It may be in the diff , but let's hope not ...that really sounds like axle u joints under load .

 

[JMT]

Time for an upgrade, 4340 chromoly shafts with Spicer 5-1310X sealed ujoints! Just Empty Every Pocket

 

[fuse]

Time for an upgrade, 4340 chromoly shafts with Spicer 5-1310X sealed ujoints! Just Empty Every Pocket

Just borrowed a friend's SB150 for a couple of rides. That may be where the money goes!

 

[Alex01]

Have you checked torque on everything connected to the front axle? (control arms, TB, etc.)

 

[fuse]

Have you checked torque on everything connected to the front axle? (control arms, TB, etc.)

Yes. Just installed Savvy control arms in the front. The problem started before that and is still happening after the install. (I had hoped it was something simple like that.)

 

[xxdabroxx]

I once had a clicking noise when making tight turns in parking lots. I replaced my U joints in the front shafts but the noise ended up being a rock that was trapped behind the rotor hat. Totally strange.

 

[fuse]

I once had a clicking noise when making tight turns in parking lots. I replaced my U joints in the front shafts but the noise ended up being a rock that was trapped behind the rotor hat. Totally strange.

That is totally weird. Glad you found it!

 

[fuse]

OK. I've got some pretty clear results.

Do the joints seem to be seeping grease past the seals? I put my hand on the u-joint caps and twist the driveshaft back and forth. Usually I can feel slop if the joint is worn.

Everything there is pretty dry, but that's sort of a result of driving in the desert then power washing off all the dust. However, there may be a little grease at the ends of the u-joint caps.

Also, while I was feeling around the caps, I was able to wiggle the axle shaft a bit and feel some movement on the passenger-side u-joint. That's a pretty clear indication that there's a problem.

Spray a quality lubricant on the U-joints and unit bearing... If that quiet and sit down for a few feet then you're probably in the right direction.

I tried that, but it didn't seem to do anything. Maybe the u-joint is far enough gone that a little spray lube isn't going to help.

Following @qslim's mention of the ChassisEars, I wrapped a Bluetooth headset in tissues to cut out some of the surrounding noise and duct taped it to the diff cover. Then used it to call myself on another phone. Made a couple three-point turns and could hear the popping out the window but not through the phone. Moved the headset to the steering knuckle and could hear the popping clearly through the phone.

So, we have a winner. Bad passenger-side u-joint. I'm ordering Spicer 5-760X replacements.

I dug up some of the online write-ups, and I guess I'm willing to go ahead and tackle this job on my own, even though I usually make a hash of anything that requires a press. Looks like Stu Olson has some good tips on removing and installing u-joints with a ball joint tool: https://www.stu-offroad.com/axle/ujoint1/u-joint-1.htm

Thanks everyone for the tips!

 

[AndyG]

OK. I've got some pretty clear results.


Everything there is pretty dry, but that's sort of a result of driving in the desert then power washing off all the dust. However, there may be a little grease at the ends of the u-joint caps.

Also, while I was feeling around the caps, I was able to wiggle the axle shaft a bit and feel some movement on the passenger-side u-joint. That's a pretty clear indication that there's a problem.


I tried that, but it didn't seem to do anything. Maybe the u-joint is far enough gone that a little spray lube isn't going to help.

Following @qslim's mention of the ChassisEars, I wrapped a Bluetooth headset in tissues to cut out some of the surrounding noise and duct taped it to the diff cover. Then used it to call myself on another phone. Made a couple three-point turns and could hear the popping out the window but not through the phone. Moved the headset to the steering knuckle and could hear the popping clearly through the phone.

So, we have a winner. Bad passenger-side u-joint. I'm ordering Spicer 5-760X replacements.

I dug up some of the online write-ups, and I guess I'm willing to go ahead and tackle this job on my own, even though I usually make a hash of anything that requires a press. Looks like Stu Olson has some good tips on removing and installing u-joints with a ball joint tool: https://www.stu-offroad.com/axle/ujoint1/u-joint-1.htm

Thanks everyone for the tips!

Pressure washing is death on components... Generally I prefer simple green and hose pressure.. my TJ really was the same story... 20,000 miles and
dude it was fried underneath.

They would hit the mud and then hit it with the pressure washer... Then roll it into a dark damp garage to dry slowly.

I know this sounds crazy... But if you play around with unit bearing you'll notice you can carefully remove the seals and pack that thing with grease. . I do the same thing on dirt bikes...grease it right inside the hub... Always remember... Anywhere you have grease is somewhere water can't go.

 

[AndyG]

I once had a clicking noise when making tight turns in parking lots. I replaced my U joints in the front shafts but the noise ended up being a rock that was trapped behind the rotor hat. Totally strange.

I actually thought about something freaky like that as well.