Drive shaft / U joint question.

2011 v6, 6spd, 4x4.
92k miles.
Can adding 1 inch of rear lift cause any vibration issue? Only happens around 20 mph when decelerating. I added the one blocks to compensate for sag. It was there before but not as noticeable. Keep in mind the center support bearing isn't trashed but does have about an inch of play. I have a new Spicer one that I haven't installed yet. U joints "appear" OK and are original, get greased once a year.
Opinions appreciated
Dave

 

It is recommended to replace center support bearing when there is a 1/4" of play. The 1" lift is not an issue. I would recommend replacing that center support bearing (it is trashed, may not look like it from the outside) and while at it all three joints. I had a driveline shop do mine with all new Spicer parts and rebalanced and it was just shy of $400.00.

 

U can replace all u joints and center bearing yourself for less $200 including u joint press. Check rear u joint, have blown through 2 already

 

I kind of figured 1" lift shouldn't be the problem, probably aggravating the worn support bearing.
And to the 2nd poster, I have a ball joints press.
I'm going to have fix this soon.

What about that spline with the boot over it?
Thought I heard something about opening it and re lubing.

 

You need to measure your drive shaft angle and possibly put in a shim I had a similar issue my deavers jacked up my rear way too high I had them take out to leafs and rearch and fixed the problem (my pinion angle was super angled)

 

How much lift did the Deavers give? My 1" lift only brought the oem ride height after the Toyota 4 pack recall's aged. My truck has a barely noticeable forward rake.

 

I added some helper springs last year which raised my rear end about 2". I had no new vibrations from it.

 

Your carrier bearing is probably the culprit. Stick a GoPro underneath pointed at the carrier bearing and recreate the conditions that make the vibration happen. You'll probably be surprised at the amount of play in dynamic conditions.

I'm lifted 4" and get no driveline vibration, but that's neither here nor there.

 

Old/soft springs will wrap/sag and cause drivetrain issues. If after changing the above parts you still have an issue you can look at springs.
There is a huge post on vibrations to read.