Metallic grinding noise during full turns

jrmcafee

TJ Enthusiast
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Joined
Feb 2, 2021
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176
Location
West Tennessee
In January I bought my first TJ and paid too much for it... there, said it. It's a 2.5L with 85k original miles and no rust, so I got excited and overlooked too many other things.

That said, the PO told me the ring/pinion in the front diff was missing and the transfer case was disconnected. When I removed 3" of body lift in it, the off-road shop reconnected the T/C. Shortly thereafter, I started noticing a lot of metallic grind/crunch sound at low speed and almost-full rotation left or right. I thought it was likely due to axle/hub issues, so I replaced the hubs along with tie rod, drag link, and sway bar links. Also removed the front driveshaft since it's unnecessary without 4WD gearing.

Grind/crunch is still there, and perhaps more pronounced than ever. I'm assuming this is something to do with the front diff? All new fluids and seals when the hubs were replaced and the front driveshaft removed.

Thoughts? Clearly I'm doing some damage, but unclear on what that damage is and what the next best step is.
 
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Either I’ve found a way to stump the internet or my question is so inane no one is courageous enough to engage me at this point?

So I win?
 
I would put it on jack stands and look the whole front end over. See if you can’t reproduce the noise by spinning/turning the tires by hand when they’re off the ground.
 
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I would put it on jack stands and look the whole front end over. See if you can’t reproduce the noise by spinning/turning the tires by hand when they’re off the ground.
Hadn’t thought about trying to manually reproduce. What’s your thought if I can reproduce it with the vehicle powered down?
 
Hadn’t thought about trying to manually reproduce. What’s your thought if I can reproduce it with the vehicle powered down?
Give it a try. If you can hear the noise with the engine off it should be pretty easy to tell where it’s coming from.
 
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This is a long shot but it’s all I have to offer.

Check to see if your wheels are grinding against your sway bar links. Happened to me once when I made the mistake of installing the bolt backward.

Edit: You can see how this happened to me here. Click on the pics to enlarge.
 
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if you are grinding on suspension components, you should be seeing some shiny metal somewhere down there. I assume you’ve looked at brake backing plates and front calipers/rotors?
 
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Have you pulled the cover off the front diff? Actually seen whats going on in the diff? If the Ring is missing or both the ring and pinion? Is the carrier still in there? Thats where I would start pull the cover and take a look. Especially if nothing else stands out as a problem. It would seem to me, I am not expert, but if the pinion is missing, how are you keeping gear oil in the diff?
 
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This is a long shot but it’s all I have to offer.

Check to see if your wheels are grinding against your sway bar links. Happened to me once when I made the mistake of installing the bolt backward.

Edit: You can see how this happened to me here. Click on the pics to enlarge.
You know, I hadn't thought about it but I could see that. Problem is that I had JKS disconnects and it did it, and a couple of months ago I replaced them with fixed links from RC and it still does it, so I'm inclined to rule it out. Good thought though.
 
if you are grinding on suspension components, you should be seeing some shiny metal somewhere down there. I assume you’ve looked at brake backing plates and front calipers/rotors?
Yeah I agree. I haven't seen anything external with pretty close examination. I would also assume I'd see some "knock-off" shavings in my driveway/garage since that's one of the most common places. It does seem like it must be somewhere in the front axle/differential perhaps.
 
Have you pulled the cover off the front diff? Actually seen whats going on in the diff? If the Ring is missing or both the ring and pinion? Is the carrier still in there? Thats where I would start pull the cover and take a look. Especially if nothing else stands out as a problem. It would seem to me, I am not expert, but if the pinion is missing, how are you keeping gear oil in the diff?
My buddy at the shop who replaced the fluid and seals grabbed a pic of the inside of the front diff. I will see if he can send it to me. He took it because I hadn't told him the r/p wasn't there, so he was surprised when he didn't see it.
 
Alright here it is. Doesn't look like the inside of any other Wrangler diff pic I've seen, which doesn't seem like a good thing. Educate me please. What am I up against here?

258842125_289306153108769_631824335770299160_n.jpg
 
I've never seen that but like you said, they removed the ring gear at a minimum. Can you see behind where the pinion gear should be? Was the oil clean? If it doesn't complain or grind it's fine like that if you don't mind 2wd.
 
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I've never seen that but like you said, they removed the ring gear at a minimum. Can you see behind where the pinion gear should be? Was the oil clean? If it doesn't complain or grind it's fine like that if you don't mind 2wd.
That's the question I'm wrestling with. Would this cause a grind/crunch at full left or full right? Theoretically no, but a grind/crunch we have. The missing gearing and the presence of the grind seem related.
 
35 x 12.5 tires rubbing the control arms when fully turned?
It had 35/12.50/15 on it but now they're 33/11.50/17 with 4" of suspension lift and 1.5" spacers (the wheels are JK sports). I don't think that's it but to your point, better to eliminate all possibilities.