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Discussion Starter #1
drove the truck last week on a trip across the state. Passed a 6.7 PSD truck doing 50 MPH in a 55 MPH, got up to about 70 MPH, and heard a sound, like a piece of metal hitting something. Hmm. Didn't notice anything at that time, but when I got on the expressway I definitely had a significant vibration starting at about 70 MPH and above.
It definitely feels like a driveshaft (or related) vibration to me, based on the frequency (much too high to be a tire or something of the sorts). Dependent on vehicle speed only, not engine speed or percent right pedal.
I was hoping it was a U-joint or a support bearing, so I pulled the driveshaft. No such luck. All joints and bearing feel like new. They appear to be original joints, and I was kind of shocked they felt like they did being 17 years and 196k miles old.
I did notice a place on the forward section that sure looks like something was attached and is no longer attached.





I'm not used to seeing balancing weights attached in the middle of a shaft, and the shaft still has weights attached at the ends. Could have this been possibly a metal tag? Or additional weights? I wish I would have looked at the shaft beforehand, but hindsight is 20/20. Has anyone else seen something attached to the shaft at this location (pictures)? If there was something there, it flying off at 70 MPH would sure explain the noise I heard.
As of now my plan is to take the shaft to a driveline shop and see what they can do with it, unless anyone has a better suggestion?
Sometimes it gets old every time I drive my truck I become aware of something else that needs attention. Ah, I still enjoy this thing though :smile:
Thanks all!
 

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i will also note that i did all my bearings and carrier at like 110 k just for PM reasons and the u joints were fine but there was no grease left so the days were numbered
 

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Discussion Starter #4
First, it looks like my picture insertion format was not acceptable. Just attached them to this post so this thread isn't pictureless... too bad about the small quality.
Anyway, yes, I sure do wonder what was there. Assuming the sound I heard was something coming off the driveshaft it surely wasn't a sticker.
I did do a little poking around for a complete new driveshaft, but I didn't find anything promising. Any suggestions? I'll probably take the shaft to the shop and see what they say. I've had them do drivesahft work for me before.
When I said the joints/bearing in the shaft felt like new, I wasn't exaggerating. I don't mean just they were free and not binding/loose, I mean they felt like they were just greased. Pretty amazing. I'm sure if the shaft gets rebuilt all of them will be replaced anyway.
 

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Discussion Starter #5
Well, it's my duty to update this tread, and thankfully it has a happy ending!
I removed the driveshaft again and took it to a driveline shop. I've used another more well known shop in the area in the past, but coworkers (another PSD guy) recommended CCI Driveline in Casco, MI (about 45 minutes from me). I cannot speak highly enough of my experience with them. I dropped the shaft off late Wednesday afternoon. They gave it a brief visual inspection and recommended a rebuild. I got a call the next day, not even 24 hours later that it was done.
All three universals and carrier bearing were replaced. Without any input from me they used genuine Spicer/Dana parts. On top of this they not only balanced the shaft assembly but corrected slight bows in both shafts. Just under $300 total.
I picked up the shaft early this morning. By early afternoon I was ready to test drive. Wow!!! The truck has never been this smooth. It's literally perfectly glass smooth to at least 80 MPH (haven't tried anything more – no reason to).
I'm so relieved this is remedied. I hate driveline vibrations!
 

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this is why i don't DIY my driveshaft work
sure you can assume the shaft is in balance if the weights are in place and you can swap joints and carrier bearings
but to get the shaft true and balanced is worth the $$$ to me
 

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Discussion Starter #7
this is why i don't DIY my driveshaft work
sure you can assume the shaft is in balance if the weights are in place and you can swap joints and carrier bearings
but to get the shaft true and balanced is worth the $$$ to me
Yep, exactly. The thing is if I were just to replace the u-joints and bearing that would probably be $100-$150 in parts alone. Maybe it would have been alright, maybe not. But for less than $300 I have something that's better than it ever would have been with just replacing parts. Now if the question was trying $100-$150 in new parts verses a $600-$700 completely new shaft, that might be a different story. Plus, the guy who did the work on mine said even new OE shafts commonly aren't 100% straight and have slight bows to them.
 

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in all honesty, I had all new Spicer parts ready to go and when i had the two piece shaft out i was already fighting it's awkwardness

i was secretly happy when my press failed me and i decided to take this in to the shop LOL

if it was a front shaft or one u jointed axle shaft then no big deal but the two peice , a carrier or a cardan joint and any rear drive shaft is worth taking in to a good shop IMO
 
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