You may be right.... your issue sounds exactly like mine! I think being a diesel made it feel worse too because of the amount of torque applied under acceleration... Im just so glad it is fixed! One step closer...

 

In my case, the drive shaft had a mark on the trans and slip yoke, and one on the diff that I didn't notice when I removed it and put it back the first time. When i saw those and re-aligned them, everything was perfect again. At that time, I also noticed a balance weight on the back part of the driveshaft. Oh, and this car had 475hp (minimum) so probably almost as much tq as your deisel!

 

Total side bar here, but during test drive, the whole cab filled with "smoke" from the vents... I assumed either heater fan resistor or heater core... went out the next day, found a puddle of coolant on the floor. I pulled out the heater core after work, and took it inside... I rinsed it out and inspected it. It is clear through, no veins are plugged, and I can blow through it, so it isnt corked up, however there is a leak where the inlet pipe meets the body of the heat exchanger. If I order a new one, I will have to wait at least a week, or I can solder this one to stop the leak, or waste my time pulling another one at the scrap yard...
Im leaning towards fixing it, but I dont know if it is worth it?? Any opinion on that one? I just dont want to put a bad part back in. Although it is not the core itself that has a leak, which is good... so I am confident the leak can be stopped without a great deal of difficulty...

Thanks!

 

How long did it take to get it out? Have ya tried NAPA to see if they might have a new one? How about a radiator shop to have it professionally fixed>???

 

I took about 2 hours to get it out… took longer than I expected because I missed a bolt holding it in way at the bottom, so I struggled for a bit…
Since the leak is not in the core, I figure it could be soldered… no different than a copper pipe on a plumbing fixture…
NAPA and other places have them for about 80 bucks. I just don’t feel right spending that kind of money when I have cars a lot older that have perfect heater cores…
Otherwise it looks perfect. I may try and repair the joint, and then do another leak search… if nothing leaks, I might get some more life out of it. Since the core itself isn’t leaking that I cant tell, I don’t think it requires a pro… it would probably cost more to get repaired than the cost of a new one.

 

to bad you live so far away. i am hoping to place a order from rockauto soon. could pick one up cheap if yours can't be fixed.

 

Ya... I just placed an order with them for a new drag link... mine is getting sloppy... THEN I found out I need a heater core... quite annoying really. I will be down to the states in 3 weeks, so I can get one for 50 bucks down there. If I cant fix it then that is what Ill do. Im pretty confident that I can solder it, but worst case is I have to wait and get a new one.

 

Hey guys, heater core seams to be fixed up... no problems now.
I went out for a good long drive, and I found the shake was still present. It was quite as bad before, but still there, especially under load. However, I think I may have made progress. I was reading a post someone put up on a Chev forum, and they said they had vibration under load as a result of mild axle wrap even under light acceleration. This was cured by adding an extra leaf spring to the rear.
My truck has no leafs in the rear. Instead, it has an air bag between the frame and lift block. There are additional frame members which are in place to handle the torque etc... however I have been running the air bags at minimum pressure for a smoother ride. What I noticed is that when the air bags are low, the axle will be closer to the frame, which will force the pinion on the diff to aim down a little bit. By increasing the pressure, the air bags lift the body and frame off the axle, thus changing the angle on the DS.
Also, with more air, the suspension becomes tighter, which is going to resist axle wrap, and lesson the likelihood of the diff flexing under acceleration.

I went out for a drive, and I THINK it made it a lot better with additional air in the sacks. I took pictures of the rear u-joint so you can see the difference in angle. I think what I will do is replace the u-joints in case either of them are damaged from the vibrations, and try driving with the bags a little more full from now on. I think the vibes also causes the rear seal on the T-case to leak a bit, so I might replace that as well. Here are the pics I took:

This is with the bags empty, the way I have been driving:

http://i1279.photobucket.com/albums/...ps30fef7e0.jpg

And this is bags full:

http://i1279.photobucket.com/albums/...psa97b769a.jpg

Im hoping it could be as simple as this... not sure if my logic makes sense... I would love some second opinions.. I tried to indicate the change in angle as best I could.

Thanks.

 

I can take more pictures if required... just let me know.

THanks.

 

Any thoughts guys? This is killing me. I dont know if the pinion angle looks bad or not??? Doesn't seem like much to me....