ok so here is my update, I tried jacking up the rear axle and unbolting the 3 bolts attached to the differential side of the rotoflex then rotated the rear wheel to align the holes to the next set, then drove the vehicle, this seemed to help but the vibration was still there, so I did it again and went to the next set of holes, this seemed to bring the vibration back to its previous strength, I then unbolted all of the bolts and advanced the rotoflex to the next set of holes making the arrows point to the nuts instead of the heads of the bolts (I saw a picture of a rotoflex installed and from what I could gather this seems to be the "Correct" way to install it) and this seemed to cut my vibrations in half, so do you guys think if I try jacking up the rear axle and unbolting the differential side again and rotating the wheels back one set of holes this should resolve my issue? or do you think this even makes any difference?
I tried this because I was thinking the gears in the rear differential had to be aligned a certain way with the driveshaft for the balance to be right.

note to Disco Mike I am trying to make removing the driveshaft a last resort because the nuts on my parking brake drum are very tight and slightly stripped, I would most likely need to cut them off to remove the drive shaft and I am trying to avoid this if possible.

 

Did you replace the bushing in the end of your drive shaft at the rear axle? There is a bushing in there that rides on a centering pin which is on the flange of the axle. The bushing wears out and that is also a cause of vibration and should be replaced with the rotoflex. I had the same thing going on with my 2001. I replaced the front driveline, still a vib. Replaced the rotoflex and bushing and no vib at all.

I welded a nut with a long 10" bolt screwed into the nut into the end of the bushing and used an adjustable wrench, adjusted to fit the bolt shank to act like a slide hammer and hammer the bushing out. I replaced the bushing by using a block of wood and a hammer to drive it back in. Be sure to pack the inside of the busing with grease.

I noticed that the old bushing was sloppy on the centering pin and the new one was tight on the pin.

 

yes I replaced that bushing, and it was a PITA! but it had to be done. however I did not put grease in there would that cause a vibration that noticeable?

 

I don't think lack of grease would cause a vibration right away but it could wear more quickly over time. The driveshaft doesn't turn on the pin, just rides there to center the driveline. My symptoms were similar to yours but these rovers are fickle.

 

I know my rotoflex is on wrong but thats because I had it right and then unbolted it and turned it one hole, I actually jacked up the rear wheel and just turned the rear flange to each of the 3 possible settings to see if that would correct a possible balance issue but it didn't help (well one seemed to be better than the other two but it may have just coincidentally seemed that way), the funny thing is when I unbolted all six bolts and rotated it one hole (causing it to be on wrong) it seemed to work the best as far as the vibration goes. I am still going to grease all my grease fittings under there soon but I don't see that causing this much vibration, at least not all at once.

I am still clueless as to what is the main cause of this vibration, I am really trying to avoid removing the rear driveshaft due to the nuts at the parking brake drum being stripped. When I was trying to get that stupid bushing out of the driveshaft to replace it I slid the driveshaft off the splines by the u joint and it is possible that upon sliding it back on I didn't slide it on the exact way it came off could this be my issue? it seemed like the splines were keyed so that the driveshaft could only slide on one way, but if this was the case then it shouldn't be offset. Are there maybe a few keyed splines that this driveshaft could slide back over? I keep thinking this may have something to do with it because the rave manual says to scribe the flanges when removing the driveshaft. I really want to get this fixed because it is driving me crazy and I am afraid I will cause more damage if I keep driving it like this (I have been driving super slow to avoid the vibration but sometimes it does it at about 1500 rpm)

 

It says phasing is only required on the front. Did you mark anything when you took it off to make sure it went back together the same? Might have clocked the slip shaft wrong and it is out of balance.

Sounds like you may need to pull the shaft and have it checked while you drive it without the rear shaft to see about vibrations.

 

I saw the phasing thing but I think that is just for the front to offset the u joints, I want removing the rear driveshaft (with the ujoints) to be my absolute last step, I can try rotating the driveshaft on the splines one turn but I wanted to make sure it would be productive before I did it.

so I drove it today and really tried to monitor the vibrations and it is off and on sometimes I can take it from a stop up to almost 3000 rpms with no vibration until it downshifts at about 45 mph or so, or it doesn't do it at all, then sometimes it is rough right off the line. Its like there is no pattern to it.

 

try parking on a flat surface and wiggling your driveline to see if there is any play. I finally figured out that I had a bad bearing in the front output shaft of my t-case this way.

 

I am going to have to wait for a few days to get under the truck, I just got a tattoo on my arm last night and don't want to get it all dirty or scratch it up. but when I get under there I will let you know what I come up with.

 

It really sounds like you may have something other than the driveline going on. A problem with an out of balance will always be there. This sounds more intermittent.

Take into account the temp of the engine and drivetrain. If it doesn't do it right away and then does it consistently after you have driven it for a while it could be a u joint. Sometime they loosen up or the reverse after driving for a bit and can cause a vibration.

It could be a shudder from the trans/torque converter.

Info on the rear u-joint.

I have the same thing with mine. When I got the truck I found that the nuts for the rear flange were loose. I tightened them... to tight it seems. I rounded off the nuts trying to get the driveline off to replace the u-joint.
I was able to replace the u-joint while the driveline flange was still on. I removed all the c clips and turned the driveline so one cap was down and used a rubber mallet to tap up on the driveshaft to push the caps out, one at a time and rotating the driveline so as to remove both caps on the flange side first. After that you can take the driveshaft off and remove the caps in the driveline.
A good soaking of the caps of w-40, kroil or something else helps this go a little easier.