I had posted regarding this already but have not heard from anyone.
I am really in a bind. The dealership had a driveline shop replace my tubes on my driveshaft and had a carrier pressed on. Before this I only had a vibration at 75mph and over. Smooth as silk up to that point.
I brought it in b/c they said I had a worn carrier at 4500 miles?
When I picked up the truck on Friday with the new carrier and tubes(which were bent) I now had a shudder at 20mph, 40mph and over 70 a slight vibration. Before last week I only had a slight vibration over 75.
The dealer told me to shimm up the carrier which I did with a 1/8th inch shim. That helped much but I still have a vibration at 40-50mph(high frequency in wheel and floorboard). I tried 1/16th and that didn't help nearly as much as the 1/8th.
Today I took it myself to the driveline shop. The guy there said I should not have to shimm anything and that it should be smooth. There is not a lift on this truck.
I came home, pulled both shafts and dropped them back off at the driveline shop.
The one thing the driveline shop told me is they balanced the two shafts in a straight line.
Should it be balanced with the rear shaft down a bit? I found that as I shimmed the carrier down and the shaft became straighter the truck became smoother. That makes me think the angle of balancing has something to do with this problem.
The dealer wanted to pull an entire driveline from another truck on the lot but there was not one.
If anyone has any suggestions please chime in. This is becoming more aggravating every day:(

I wish someone would chime in. Took my newly tubed driveshaft back again today to the driveline shop. They said it was balanced and they don't know why I still have problems. Dealer's only solution is to shimm up this truck which to me is a bandaid. It didn't need shimms last week, why all of a sudden? No lifts or anything.
What I did notice yesterday when it was on the truck was that the driveshaft was hot up by the tranny. That's also where the driveline shop said most of the warp in the shaft was.
So, when I picked up the shaft today I checked the Ujoint on the tranny side. One cap felt like it had restriction and sure enought I pulled it off, wiped off the grease and saw some significant wear marks on the metal. Checked the rear end Ujoint and that too had some restriction and had some wear but the the one on the tranny side was much worse.
Not sure if it is normal for the shaft to be warm up by the tranny but if it is not then the Ujoint probably is heating up causing the shaft to become warm and that's what caused my tubes to be warped....
If that's not it then I'm totally lost. Dealer hasn't a clue and will order me the Ujoints and put them in...

I wish someone would chime in. Took my newly tubed driveshaft back again today to the driveline shop. They said it was balanced and they don't know why I still have problems. Dealer's only solution is to shimm up this truck which to me is a bandaid. It didn't need shimms last week, why all of a sudden? No lifts or anything.
What I did notice yesterday when it was on the truck was that the driveshaft was hot up by the tranny. That's also where the driveline shop said most of the warp in the shaft was.
So, when I picked up the shaft today I checked the Ujoint on the tranny side. One cap felt like it had restriction and sure enought I pulled it off, wiped off the grease and saw some significant wear marks on the metal. Checked the rear end Ujoint and that too had some restriction and had some wear but the the one on the tranny side was much worse.
Not sure if it is normal for the shaft to be warm up by the tranny but if it is not then the Ujoint probably is heating up causing the shaft to become warm and that's what caused my tubes to be warped....
If that's not it then I'm totally lost. Dealer hasn't a clue and will order me the Ujoints and put them in...

The shaft near the output of the tranny will be hot. The problem is probably your U-joints...surprised your driveline shop did not notice them. I took my shaft to a drive line shop a few weeks ago for a balance. 1 week before I took it there, I installed new U joints (NAPA). They were already showing signs of wear with 200 miles on them. The driveline shop replaced them with Spicers and balanced the shaft. All is good now. U joints can be funny sometimes. Even if they feel tight, they could still be bad. I do recommend the OEM U-joints from the dealer though, my original set lasted over 100K.

The shaft near the output of the tranny will be hot. The problem is probably your U-joints...surprised your driveline shop did not notice them. I took my shaft to a drive line shop a few weeks ago for a balance. 1 week before I took it there, I installed new U joints (NAPA). They were already showing signs of wear with 200 miles on them. The driveline shop replaced them with Spicers and balanced the shaft. All is good now. U joints can be funny sometimes. Even if they feel tight, they could still be bad. I do recommend the OEM U-joints from the dealer though, my original set lasted over 100K.

Thanks for the reply.
The Ujoints in my truck are Spicer and have 5K on them, that's it. Are you certain the front of the front driveshaft should be hot? I can definitely see when I pulled the cap off the one side of the Ujoint that the metal was marred in one area and when I spun the cap it didn't turn smoothly. It felt as if it had dirt or grit in it...
I just have a hard time believing this truck, 2wd, I drive it easy, never one burnout or lashing, have towed only a couple of times with a trailer no more then 2500lbs... What gives?
I wish one of the driveline guru's would chime in. The dealer will try the Ujoints first. If that doesn't work they want to shim up the carrier bearing... I don't agree with that one bit!

Why not have them make you up a 1 piece drive shaft?

I'm not a driveline expert or anything but that seems like a logical solution.

Why not have them make you up a 1 piece drive shaft?

I'm not a driveline expert or anything but that seems like a logical solution.

I don't think you can put a 1 piece on a CCSB 2WD. The driveline shop said they wouldn't do it...? Dealer won't do it because it's not what the truck calls for. If it was not an 07' and under warranty I'd be looking for an aftermarket shaft.

i would change out the u joints. your truck probably got a bad set from the factory. i will bet that helps alot. any wear on a u joint will definatly cause a vibration(i have changed hundreds of em)

Why would the dealership have new shafts made when it is a new truck with only what 4500-5000 miles? They should be ordering you either new shafts or a one peice from GM itself. I dont think that GM is going to warranty shafts from an outside manufacturer besides thier own. I agree with some of the other post about u-joints. Sounds to me the dealer has misdiagnosed your truck and concern. Just my two cents.

I hope you guys are right about the Ujoints. I'm out of options. I like the tubes the driveline shop put on. They are much heavier then the stock tubes.
The funny thing is I'm the one who noticed the Ujoints not feeling right and when I pulled one cap off and showed it to the guy at the driveline shop he was surprised to see the scouring on the metal.
Should I have the whole assembly balanced again once all the Ujoints are changed out? I assume I should but the dealer may not agree.

If your truck is an '07 and still under warranty, why are you pulling your driveshaft and taking it to the driveline shop? Shouldn't the dealer be doing that? Sounds to me like you need a new dealer and a new driveline shop. If you live near Nashville I can recommend a good shop.

If your truck is an '07 and still under warranty, why are you pulling your driveshaft and taking it to the driveline shop? Shouldn't the dealer be doing that? Sounds to me like you need a new dealer and a new driveline shop. If you live near Nashville I can recommend a good shop.

Yes, I would like a new dealer but the closest is 30 minutes away. The dealer is nothing more than a parts changing warehouse. It seems as though every time I take my truck to them it ends up having another issue. They don't care, they just tell me to bring it back and they'll fix it but it's still my time. I'd rather do it myself and know it's done correctly. They could have pulled the driveshaft and done what I did but I'd be without my truck an xtra 2 days. The dealer's rationale about this whole thing is to just bandaid it. If they had it their way they would have shimmed the carrier bearing and told me to live with it. My argument is the truck didn't need shmming last week, why all of a sudden do I have to shimm it. Again, they are treating symptoms, not the underlying problems because they seem to not have the ability of a true mechanic who will methodically figure things out.
I could write a book about my experience over the last 6 months. Right now it's easier to troubleshoot it myself and save the xtra time driving to and from the dealership.

This may be a real dumb question, are the universal yokes in the same phase with each other eg. ---- ---- ---- ---- (all horizontal) and square to the bearings, also you have a sliding yoke, is it greased up with a high pressure grease, and sliding freely???

good luck

This may be a real dumb question, are the universal yokes in the same phase with each other eg. ---- ---- ---- ---- (all horizontal) and square to the bearings, also you have a sliding yoke, is it greased up with a high pressure grease, and sliding freely???

good luck

No, not a dumb question. Everything was marked when removed and the driveline shop said it should not matter once the shaft is removed as long as the front and rear shaft are put in the same way they were balanced, in other words not 180 out from where they were balanced. Not sure how important the yoke alignment is once the shafts are balanced. Are you saying the yokes should be oriented front and rear exactly the same when putting in the shaft? The splines were greased well and sliding freely.

Update:
After putting new tubes on my driveshaft I still had a vibration at 40mph and 20mph I did not have before. The dealer had already messed with it and sent the original shaft back to have a carrier pressed on. That made it worse. Dealer said driveline shop warped shaft. Sent shaft back to driveline and they confirmed the warp and put new tubes on, thicker ones. Dealer put it back in and there was still a vibration I felt on the way home.
I pulled the driveshaft out myself and took it back to the driveline shop. They said it was in balance and they tweaked it just a bit. While leaving I noticed one of the caps on the front Ujoint was not spinning. I asked the tech if that could be a problem. He said yes. I promptly took both shafts to the dealer and showed the shop foreman. They agreed it was not right and ordered ujoints for both shafts. Dealer ordered them Wed. got them in on Friday but one was defective so they ordered another. Got them in Monday and I picked up the shaft at lunch.
I installed it tonite and it is much better but there is only a shudder on hard acceleration at about 20mph. Over 20 and up to 90mph is smooth as glass. The shafts are lined up the way they were balanced. I rotated the rear yoke and I'll give that a try. Any suggestions at this point would be very helpful....:D