What's causing my vibrations at 20-40mph?

alright I've been reading for hours and hours about them and shims, its almost 1 am and I'm tired and want input.
have hd leafpack in the rear 25" from center of hub to fender. so prob 1.5" lift in rear and billy 5100s
front have stock coils set at 2.5 on billy 5100s
also have Diff drop installed up front (never drove the truck without it before the front shocks were put in so have no reference for vibe)
i was driving with just the rear done and had same vibes as below
i have a slight vibe from 20-40. nothing too major but want it gone. i have heard start with washers at cb and test it by adding. i have heard the diff drop is useless and i wasted money, but also heard you need it for 2.5-3" lifts. i heard shims are both shit and also the only way to go.

is the diff drop going to hurt anything? should i take it out and see if it helps, will that be causing kind of vibes. I'm going crazy here people

 

the issue I see with a center bearing drop is that it also changes the angle of the joint at the transmission.. And now you have 3 angles trying to cancel eachother. The joint at the transmission should really never change. It should just be viewed as an extension of the output shaft. The rear two are the ones you want trying to cancel eachother. So you have to get them both equal by shimming the axle

 

so diff drop is pointless? and has no say in vibration

 

I didnt use one with my lift so no experience with the install but I have 2.5" w/o the diff drop- it will not hurt to run without it so feel free to experiment. The idea of a diff drop is centered around improving drive line angles- seems to me most people ont eh 2nd gen dont use them- but driving around for a week will not kill anything. Hope that helps in the early hours.

 

I was just referring to the CB drop.

 

Front diff drop is useless, but won't hurt anything and won't cause vibes.
I would start with washers on the cb, one at a time and see what changes.
If you read enough, you'll find that suspension lifts are a crap shoot, what works for one doesn't work for another so you have figure out what works for your truck.



For reference my truck has 1" blocks and 11/2 add a leaf with 3*shims, vibes are from 0 to 10 mph but so small that I don't worry about it.

 

One piece drive shaft and no diff drop. Nothing else to say now. Good luck.

 

i get a one piece will end all but i don't have the money for that currently

 

$295 to $345, never go back, do it right.
http://www.driveshaftsuperstore.com/CUSTOM_Toyota_drive_shafts.htm
Here is my rig.

 

What one did you get. They all seem tonbe 2 piece

 

http://youtu.be/f1m-Fh5kiRU

 

I buy all of my DS from Tom Woods, but your going to spend more. http://www.4xshaft.com
Here is my Jeep with custom shafts.

 

I just lifted my rear 1.5" (on top of TSB) and have similar vibrations. Some on takeoff 5-10mph and then slight at 20-30. I tried washers one by one up to 3/8 thick but it made it worse, so back to none.

It's not that bad and I don't notice it all the time, but I want the drive train to be harmonized. I'm thinking about a 2 degree axle shim.

 

So you take it apart, install this, install that, try something else, hope it works, oh well, now try something else. Wow. 15 minutes, replace drive shaft with one piece. No vibs, ever, problem solved. Done!

 

If I had the money laying around I'd buy a new driveshaft, for sure.

 

I understand. Ask Santa, sell something, don't lift your shit. Just saying, do it right the 1st time and you will be much better off in the long run. Good luck.

 

So you're suggesting that everyone who lifts their Tacoma, even only 2 inches, buy a one piece driveshaft without troubleshooting a little and seeing if they can keep their 2 piece? To each their own.

 

1

These stupid little trucks should have never been built with the faulty two piece POS drive shaft. I could have lifted my Jeep with a couple of bolts welded between the springs, but I decided to lift it with this crap.

 

Not sure if it's like the 3rd gens but does the vibe go away in 4hi? Try it on a straight flat road. If so possibly needle bearing. Replaced mine with ECGS bushing after small lift and vibe/rumble strip feeling is gone. I was getting them around 20-50mph. Just a thought.