Metallic clunk when accelerating or decelerating

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Hey y’all I’m having an intermittent metallic clunk when accelerating or deceleration. I haven’t been able to see it but it’s def not the u joint. It’s like a sharp metallic clang/clunk. Like hitting two metal bars together. Any ideas? Sounds like Maybe transfer case. 1983 fj60
PS you guys are a great resource. Thanks in advance for the knowledge.
 
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Started after this debacle in the bad lands of South Dakota.

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I had a similar sound that worsened and became a chatter/roaring sound anytime the load changed when shifting. It was really bad on deceleration. It was the idler shaft in the tcase. All the bearings were worn out too.

But it could be in the diff. Check your pinion. Pull the drive shaft and see if you have any lateral movement or movement forward and back. It should be rock solid. You will feel a bit of gear lash when you rotate the pinion but it shouldn’t move side to side or in and out at all. If it does call cruiser outfitters and they’ll send you a rebuilt drop in unit for around $600-700.
 
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I had a similar sound that worsened and became a chatter/roaring sound anytime the load changed when shifting. It was really bad on deceleration. It was the idler shaft in the tcase. All the bearings were worn out too.

But it could be in the diff. Check your pinion. Pull the drive shaft and see if you have any lateral movement or movement forward and back. It should be rock solid. You will feel a bit of gear lash when you rotate the pinion but it shouldn’t move side to side or in and out at all. If it does call cruiser outfitters and they’ll send you a rebuilt drop in unit for around $600-700.
Thanks man. I think it’s the Tcase. How did that job go for you?
 
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Thanks man. I think it’s the Tcase. How did that job go for you?
It’s fairly straight forward. You do need some special tools like a press and a small pilot bearing puller. Just pay attention. There are several videos online and lots of threads here that walk you through step by step.
A tip to deal with pulling the transmission: go to harbor freight and get the 800 pound transmission jack. Make sure you grease it, bleed the fluid, and oil the threads in the adjusters. Then take a piece of plywood and mount it to the jack and drill holes in the wood to take the bolts from the transmission mount. Then you can bolt the thing straight to the jack without worrying about it tipping over. If you do the prep to the jack first it works really well. I pulled and reinstalled mine alone. Overall the work took longer than I expected but it’s definitely doable. I built the case on the jack.
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You can kinda see in the last picture where the trans mount is bolted to the plywood base.
 
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Oh jeeze you gotta pull the whole tyranny. I’m on the road now. I’m gonna hold out and hope it’s something else.
 
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Oh jeeze you gotta pull the whole tyranny. I’m on the road now. I’m gonna hold out and hope it’s something else.
You technically could do it in the truck. It would be a real PITA... but you still need a press and bearing pullers and some other stuff. It really is a garage type of deal.
 

Godwin

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Slip joint in the driveshaft may be worn and/or needing a squirt of grease. The hollow tube can really amplify the metallic noise.
 
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Slip joint in the driveshaft may be worn and/or needing a squirt of grease. The hollow tube can really amplify the metallic noise.
That is certainly true. If you got a bunch of muddy water in it maybe it washed any grease in there away? That could be it.
 
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I just hit it up with a tube of grease. Will she how it sounds tomorrow. I’m actually putting her on a boat to Alaska tomorrow. Hahaha. I pulled the shaft off and felt the rear diff today and there was a mil or two of play at the mounting plate, (side to side, not lash, there’s quite a bit of lash, too much maybe.) it’s hard to diagnose now because nothing is really busted yet and it’s still subtle.
 
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I just hit it up with a tube of grease. Will she how it sounds tomorrow. I’m actually putting her on a boat to Alaska tomorrow. Hahaha. I pulled the shaft off and felt the rear diff today and there was a mil or two of play at the mounting plate, (side to side, not lash, there’s quite a bit of lash, too much maybe.) it’s hard to diagnose now because nothing is really busted yet and it’s still subtle.
For what it’s worth, I ran my diffs and t case with some gnarly howling and chattering for almost five years before I replaced the bearings. It got progressively worse and made me nervous but never let me down. That’s not to say it’s always the case. I’ve heard people say the diff started howling and then failed 500 miles later. Also, I wasn’t wheeling it at all. Just going to work and whatnot.
 

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