well, the vibration could have ruined the new u joints…, sorry to mention it…, again…
…and DB…, you gotta go to a lower class of junkyards , man…
@db4690 Got a line on an SKF brand bearing nearby without the housing, but I got the housing… 2 housings in fact. $26. Does this pass your smell test?
Tranny and eng mounts look very good. Front section of DS is in line with tranny, determined with line laser mounted on tripod. Angle of tranny yoke and diff pinion yoke is off by 3º horizontally. They are not parallel as they should be. The rear section of DS is off 1.6º in the vertical plane from the tranny and front DS section. This is all stock stuff, although things may have moved around after 140,000 miles.
@“Jack Dak87”
Here’s another thing I would do . . .
Carefully and slowly jack up the engine . . . with a piece of wood between the jack and oil pan . . . while you watch the mount. You will quickly see if the mount is okay, collapsed, oil-soaked, etc.
Then do the same thing with the transmission . . .
you will know when to stop pumping 
If they are in excellent shape, you should not be able to “stretch” them much at all
I happen to think SKF makes good bearings
however, I’d spend a little more time looking at those mounts, before condemning the bearing again
I checked and rechecked the ujoint angles, made sure I thoroughly understood the Spicer manual for correct angles for a 2-piece shaft, and mine are well within acceptable parameters. And since replacing the center support bearing for a second time did, in fact eliminate the vibration above 50mph, I have to assume that the original center support bearing replacement was defective, and the one I replaced it with ain’t so good, either, but no where near as bad, seeing as how it eliminated the vibration above 50mph. I plan on ordering the next one from a manufacturer with a well established reputation.
Bearing in mind all you said in your last post about the mounts, the plain inescapable fact remains that I had no vibration whatsoever before I changed the original ujoints and center support bearing, not even with the rear ujoint being completely shot and rubber casing in the center support bearing being shot as well.
Both sets of ujoints were from reputable companies, and were properly installed. The same cannot be said of the center support bearings, for while both were properly installed, neither was from a reputable company. I’m going with the center support bearing that is on their now, the Anchor brand you warned me against, being subpar quality.
But I will run the test you mentioned to check the mounts… but not tonight.
@“Jack Dak87”
I’m not at all suggesting your mounts are bad, or the cause of any particular problem
I just gave advice for checking them
I feel in a situation such as this, a person should be systematic, and rule things out, one at a time
As you have already been doing
p.s. please don’t get mad at me if my “hunches” are wrong 
Take a look at whatever the CB is mounted to, to make sure it isn’t deformed, twisted, or coming loose.
Not mad at all, just focusing on a aspect of this problem that focuses attention on what was changed just before the problem arose and that is: U-joints and center support bearing. The fact that the second new center support bearing eliminated the problem of vibration at 50+ mph present with the first, albeit introducing a new one, vibration from 43mph to 48mph, points to subpar quality center support bearings. Changing the new quality u-joints with another set of quality u-joints changed absolutely nothing.
The u-joint angles didn’t change either, but, in the interest of being systematic, I painstakingly checked them. They checked out. If the u-joint angles are within acceptable parameters of established practice, and the motor and transmission mounts pass a visual test, suspicion of them falls away.
The only component upon which suspicion falls heavily is the carrier bearing. Therefore, my only recourse is to change it a third time, but this time with one from a reputable company.
@GeorgeSanJose “Take a look at whatever the CB is mounted to”
I was up close and personal with just that component today. Loosened the four bolts that attached this 8"x10" steel plate to the frame to see what play it had in it, then tightened it back up. It’s fine and hasn’t changed from two weeks ago when there was no vibration.
If you have a vibration within the parameters that you listed…that can EASILY be tire or wheel related. Many people forget to have their wheels re-balanced as the tires wear…the weights that were correct to offset any imbalance when the tread was new…will now be overwhelming to the tire as it loses weight along its out circumference. A vibration like you described seems like something wheel related to me. If I am correct about wheel balancing…it may also be shining a light on worn shocks as well?
Now that you are Hyper-Sensitive to vibes…you may be catching something you missed prior? Just a thought
Blackbird
@Honda Blackbird
Regarding the possibility of the vibration being tire related: I didn’t have vibration at 45 mph three days ago Just before I put on this 2nd new center support bearing. When I had the vibration at 55 and higher with the first new center support bearing, at your suggestion, I took off the tires and drums and still got the vibration. I think the tires can safely be ruled out.
I AM hyper sensitive to vibration now, but what I was getting at 55+ with the first unit and now at 45 with the second unit is obvious, is not the result of hypersensitivity and was not present until after the work was done.
The one last thing I have to try before ordering a Spicer is to reverse the pinion ujoint 180º. I doubt that will do it, but I have to try everything I can.
I would definitely try it flipped 180, and I would check the tires for bulges from a burst belt as well…
Agreed…Nice work tho… you are whittling away at this like a pro. You will suss it out I’m sure of that! Even if it takes till Next Year man !!!
Blackbird
@“Honda Blackbird” @wesw
Flipping the pinion yoke 180 seemed to do the trick. I have to reach when I hit 45 to feel any vibration. I had flipped it several times in the course of of troubleshooting and to be honest, I don’t know for sure whether it is in the original position or not. Whatever yellow keel marks I put on it have been rubbed off from turning and handling. I have photos from before I did any work, so should be able to tell, but that’s for another day. I’m going to reseat the front wheel bearings and drive it for a while and if it don’t feel broke, I ain’t gonna fix it.
At this point, whatever vibration I feel is so slight that it could have been there all along or I am imagining it. If it stays that way for a month I will consider it fixed.
Next project is to swap out the Holley 2280 carb for for a brand new Holley 6280. The original 6280 has been kaput for over 12 years. I found new one on eBay for cheap and it is sitting behind me patiently awaiting its turn. It has a mixture control solenoid, which differentiates it from the 2280. That’s the part that is no longer available and which fails after 60,000 miles or so.
I will buy that for a dollar ! I was thinking that would have basically been your last move…I was interested to see what happened. Sounds good to me !
GREAT JOB
Blackbird
@“Honda Blackbird”
I dunno, Blackbird, GREAT JOB would have been if I hadn’t bought the cheapest center support bearing available. But then, I wouldn’t have had the pleasure of meeting everybody here.
This Driveshaft Episode Gives Me An Idea For A New Health & Fitness Book/Video.
Avoid Crowds At The Gym, Work Out On Your Vehicle!
It could be a series. After the driveshaft episode could be working out on pesky wheel bearings, or seized brake rotors, for example.
CSA
HA…No anytime you see something annoying or difficult through to resolution an Atta Boy or Good Job is in order. Don’t be so hard on yourself, I have at least 10 similar stories that turned out to be something very silly in the end.
How does your body feel after so many episodes of jacking up the truck…letting it down and the biggest body beater is how many times you went from standing to belly crawling to on your back…back up to standing again. I tell you it can be a serious aerobic exercise when you do it all day long. Sometimes I wish someone would use a time lapse camera on me when I have to repair something out in the Boonies with rudimentary equipment…I know I walk away completely exhausted sometimes, barely able to move. I often wonder how many times I went from my feet to my back…I know its more than 50 times in some cases. Hey try it if you think its easy…LOL Oh the joys of vehicle repair!
Anyway I hope we were of some assistance here. The group of regulars on this site could keep the Space Shuttle operating I tell ya… Hey if nothing else we “Egged you on” at least …Ha
Blackbird
@“common sense answer”
You could use this as image to demonstrate the Driveshaft Crunch:
@“Honda Blackbird”
Sounds like you know what I have been going through. I must have gone through a pint and a half of orange hand cleaner and the beautiful clean perfectly sized piece of double walled cardboard that my radiator came in is now a greased-stained abomination.