PLEASE HELP - driveline vibes after ECGS bushing install

Calling all driveline PROS


Hey Fellas. Got a driveline question. I have done all the work I think you will need to answer.

I have been having this weird driveline vibe from 38-44MPH and I have a feeling my rear axle shims are not steep enough. The vibes are happening at about 1200rpms the most when cruising, more-so on deceleration even when foot isn't on the gas or break. Also, I disconnected the battery to work on some electrical, when i got it hooked back up and drove there truck the vibe was gone for about 10 miles, then came back WTF?


Truck Details:
• 2016 4Dr TRD OR
• 2" OME Lift Medium weight
• 3/8" carrier bearing spacer (OME)
• Full rear dakar pack (no leaf removal)
• ECGS BUSHING INSTALLED!
• Drives amazing except for 38-44mph
• Driveline has been professionally inspected and balanced
• Shims on correct way with skinny tapered end forward


Please let me know if I need steeper shims or what? I have gone all the way from 1/16" spacer to 1/2" spacer in the CB with no luck.

I used Spicer parts calculator to figure this out. I measured the angles with a phone app and used same side of phone to measure angles without phone buttons interfering.
http://spicerparts.com/calculators/driveline-operating-angle-calculator


Someone please give me some insight because I cannot figure this out for the life of me.

Thank you for any and all help!

 

Maybe it's your tires. Did you check your tire balance?

 

Yes, tires are good. I have even messed around with PSI.

The vibe is very parabolic and harmonic in nature

 

Are you sure that you actually need messing with CB drop kit? I've read conflicting reports about it, and with only 2" it's a hit and miss. There was something about diff angle in relation with first driveshaft (cb) needing to be parallel... Damn it, I wish I had those schematics

 

So you think take the spacer out? I tried this and it seemed the same

Please find the visual if you can

 

Since you tried removing it already, and it doesnt work for in your situation, that sucks

I'll look for it anyway, since I'm getting my 2" lift together, I might need it...

 

Can't seem to find the one I spoke about ....

I came across this one, since removing cb shim did not work, might want to look at this.

Drive Shaft Vibrations Solved Step-by-Step

 

Diff drop and/or carrier bearier drop

 

Have both. Still vibes at small speed range 36-43mph

 

Thanks I appreciate it. The truck drives amazing except for these vibes at 1000-1400RPMS between 36-43mph. Biggest Pain in the A**

 

Get a one piece drive shaft. Seems to be the cure for the 2nd gen guys.

 

Yah...but what about strain on the transfer case? This seems to be an issue as well and more $$$

 

Doesn’t seem to be an issue for the 2nd gen guys after the swap.Just helped my buddy swap out his drive shaft and solved all his vib issues. And welcome to lifting Tacoma’s. New drive shaft is like 500 from Tom Woods.

 

OP, as you suspect, it's a question of your pinion angle, and can be solved with appropriate axle shims. When you accelerate, the pinion moves up by about 2*, and moves down when you get off the gas - this is why your vibrations are worse when cruising and decelerating.

 

In my local Toyota group, plus on here I see most guys running 3-4 degree rear shim. As well removing the carrier bearing drop with this combo should work better.

 

Awesome, thank you

 

I know you said you checked the tires OP, but check the wheels and how they mount. Could be a bad mounting, runout/deformation on one of the wheels, anything. Even if all the ammo points towards driveline.

Side note why aren't more people replacing the 2pc with a 1pc prop shaft? It's like a few hundred bucks and solves the carrier bearing/2pc the "right" way.

I got 4 wheels brand new out of box from Fuel that had the lug holes drilled slightly off center and I went crazy trying to find my vibration from that. My tires and wheels balanced perfect but once driving on them it sucked.

 

But I have stock TRDOR wheels. You are saying check how the tires mount to the wheel? Man I wish you guys could feel the vibes, it definitely feels driveline related because there is NO steering wheel shake, just harmonic vibes

 

Read my edited post above about the driveshaft. The 1pc driveshaft is the more expensive but fool-proof way to get rid of the CB issues and vibes without shims/spacers/etc.

If you are on stock wheels, then likely this isn't an issue. I meant like where the wheels mount to the hub. If it's dirty or uneven you can introduce vibration there.