Clunk in driveline

madmikeismad

madmikeismad

So mad
It's been clunking when you put it in gear for a while now, and just a couple days ago starting vibrating over 50mph, but only at 5-10% throttle, any more or less and the vibration almost goes away completely. Narrowed it down to the rear of the tcase or the front ujoint.

The sound sounds the same no matter where I place the stethoscope on the tcase, ujoint, or driveshaft. Ujoint has ZERO play in it, but when holding the stethoscope to it, it makes the loudest noise when jerking the driveshaft back and forth via the tire. Not sure if thats because it's the culprit, or because there's not 100lbs of iron encasing it.

Ideas? Or ways to narrow it down?

I'm going to pull the driveshaft tomorrow, put it in 4wd, and try the same method by jerking the front tire back and forth. That would tell me if it's the chain right? I'm also going to try to get the stethoscope ear piece up to the microphone on my phone, and record a decent video. I don't have high hopes for that though.
 
I pulled the rear driveshaft tonight. Checked the 2 open caps on the ujoint at the pinion end, and some of the needles fell out. Can't remember if that was a bad sign or not, been almost 9 years since I've had to touch a ujoint lol. I didn't get around to pulling the joint at the slip yoke end, but it felt like it had zero play in it when moving the yoke around by hand. Tomorrow I'm going to put the slip part back into the tcase and check it for rotational play, since I forgot to check it tonight.

I did put it in 4wd drive and shift through all the gears in the driveway, zero clunks now. So not sure if that means it was definitely in the driveshaft, or in the tcase and the bearing is just not making any noise without the driveshaft installed. I feel pretty stupid for forgetting to check it for play. But it my defense, its been a long day, its 1am, I just ate dinner, and I'm exhausted. LOL

EDIT: Also, the pinion rotates about 1/4" without the driveshaft installed. Is that ok, or does it mean it needs tightening up? 4.10 gears if it matters.
 
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I think you found your problem with the u-joint. I would change both while you have it out, just my opinion. Your pinion play sounds normal.
 
It was ujoints lol

Rear was seized

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Front

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Good find, and good troubleshooting!!! Glad it wasn't inside the transfer case or rear axle as that would have likely been a lot more expensive!
 
Make sure to do some kind of grease on your slip joint or you'll potentially have a new exciting clunk to deal with as well. Pretty common knowledge but worth pointing out IMO.
 
quito195 said:
Make sure to do some kind of grease on your slip joint or you'll potentially have a new exciting clunk to deal with as well. Pretty common knowledge but worth pointing out IMO.
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What makes you think the man posesses grease? You look at those U-Joints? :evil
 
Shainer said:
:poke: Man is there anything on your truck that isn't wore out? LOL
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lol, it did sit for 5 months and 3 seasons. But to be fair, before this, the only problems were front passenger wheel bearing at 120k, rear driver wheel bearings that I didn't catch in time at 170k, and an alternator at 120k. She's at 200k now. I've put at least 100k on everything else on the truck, plus whatever the p/o put on it. Everything else thats broken since is either a chevy part I swapped on, or broke from having fun.

Chris Tobin said:
Good find, and good troubleshooting!!! Glad it wasn't inside the transfer case or rear axle as that would have likely been a lot more expensive!
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Still not completely sure that was the problem, haven't had it back on the highway and up to speed yet. But I've run it back and forth through the gears in the driveway about 100 times, and the shift clunk is gone.
 
quito195 said:
Make sure to do some kind of grease on your slip joint or you'll potentially have a new exciting clunk to deal with as well. Pretty common knowledge but worth pointing out IMO.
Click to expand...

Shainer said:
What makes you think the man posesses grease? You look at those U-Joints? :evil
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hahahah

Honestly I've never greased the slip joint before. I figure the oil in the tcase will just strip it off after a few miles.

Speaking of, I'm going to drain and refill the tcase tonight. Whats the preferred oil these days?
 
madmikeismad said:
lol, it did sit for 5 months and 3 seasons. But to be fair, before this, the only problems were front passenger wheel bearing at 120k, rear driver wheel bearings that I didn't catch in time at 170k, and an alternator at 120k. She's at 200k now. I've put at least 100k on everything else on the truck, plus whatever the p/o put on it. Everything else thats broken since is either a chevy part I swapped on, or broke from having fun.



Still not completely sure that was the problem, haven't had it back on the highway and up to speed yet. But I've run it back and forth through the gears in the driveway about 100 times, and the shift clunk is gone.
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At 200K be ready to replace the brushes in the starter.
 
I did at 170k. It was getting slow, so just knocked it out one day. Now it's an unknown mileage starter from a member here, because the original shook hands with the rod and cam that didn't like me anymore.
 
madmikeismad said:
I did at 170k. It was getting slow, so just knocked it out one day. Now it's an unknown mileage starter from a member here, because the original shook hands with the rod and cam that didn't like me anymore.
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Oh yeah... I forgot about that carnage. Pretty sure there are easier and more cost effective methods for changing out a starter.
 
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