Driveline angles. do I need shims?

Hi Folks. I netted ~2 inch lift in the front and ~2.25 inch in the rear after installing some Dobinson's leaf springs, coils and 4 new shocks. I get a mild vibration accelerating around 20mph and a noticeable steering wheel shake when decelerating around 20 mph. attached my driveline angles before and after, and CV axle pic after the lift. Alignment cams are in the same positions as before the lift, but I have not yet driven to the alignment shop

I'm not sure how to think about alignment/carrier bearing shim/rear axle shim/ECGS. Should I get the alignment first then tackle the vibrations? thanks for your input!

 

Carrier bearing drop 1st. Its very easy to put in.

 

Have you measured your pinion angle?

edit nm I missed the diagram but ya your angle is pretty high

 

4 hi does it go away?

 

A half degree of cancellation is good but the operating angle of the rear half is way too high. You could try dropping the CB a bit first, but you’re going to need to shim the nose of the pinion up as well.

 

thank you. I did try the 4hi back to 2WD cycle several times at a few speeds. Did not seem to make a difference, so not rushing off to buy an ECGS bushing yet

 

Thank you!

 

The rule of thumb is equal and opposite on the angles.

 

Feeling less panicked now after my first real wrenching job. Coasting in Drive gives some whole-truck vibration and it sounds like a subwoofer symphony (deep and loud). But shifting to neutral while coasting to red light fixes a lot of vibration. Based on people smarter than me on TW, that suggests my pinion angle is bad and engine braking makes it worse by wrapping the axle a bit and pulling it further down. This goes away in neutral. I rush ordered a Carrier Bearing drop kit from Rough Country (item

$30 1776BOX1 Rough Country Carrier Bearing Drop Kit for 2005-2023 Toyota Tundra - 1776BOX1

1776BOX1) and used 2 of 3 spacers as a test, not much difference in vibration. Then used all 3 spacers (max carrier bearing drop for this kit) and the steering wheel shake went away, overall made things a little less dramatic.


Got an alignment from Belle Tire and I was pretty far out, pic attached. To my surprise, this fixed some of my vibrations.

I've done 2Hi to 4Hi test several times and am not convinced that my current problem is caused by needle bearing. No obvious need for ECGS for now.


So it looks like I will need some axle shims based on my driveline angles and the coasting-in-Drive-versus-Neutral phenomenon.

Thank you all for the help, much appreciated!

 

makes sense, thank you!

 

Have a 2" front/ 2-2.25" rear lift on my 07 (Icon stage 8.) Had the ECGS done at same time (didn't need it but what the hell.) Have always had a very slight take off shudder (with 2" spacer/aal lift and the current lift) and a carrier shim fixed it. No need for pinion shim as there's absolutly no vibs. Looks like a inner cv boot rib is riding.... had the same on mine. A diff drop fixed that.... been on for 17 years with zero issues. The original cv boots still look like new.... just my experience.

 

You need less than 3 degrees operating angle, and cancellation less than 1.
One thing to keep in mind is you will probably never get perfection. I’ve had four Toyota trucks and they all had/have some quirky spot where is vibrates a bit or drones even with good driveline angles

 

Good info, thank you. Will have to keep an eye on that CV boot contact and maybe mitigate

 

Great rule, that makes sense. I'll measure new driveline angles with the carrier bearing drop. Once the rear shims go in and improve the operating angle, then I might have to back off the carrier bearing drop and raise it a bit to work on the cancellation. Thanks for the advice on not getting perfect, may have to compromise and live with some quirkiness

 

Installed the shims on one side of the rear axle but cannot get the shim + leaf pack sitting down flush to the leaf spring mounting plate on the axle. The center pin is in the hole, the u-bolts fit into place, leaf spring is installed with all three bolts in, etc. I even cranked up the jack under the axle to put some pressure on the leaf spring. But it's still not sitting flush on the axle.

Will this improve after I install the shim on other side and things are more symmetrical, please?

 

Finished the other side and yes, the shims did seat down onto the perch/base plate better once both side were shimmed.

I did have to order longer center pins for the leaf springs, because my shims were too thick the center pins that came with my leaf pack. I was also worried that these were too wide on the round bolt head, maybe I couldn't fit them into the perch hole. But this also seems okay now, pics attached.

 

4 degree axle shims installed. Then I measured driveline angles as I added and removed carrier bearing drop shims. I ended up with the minimal carrier bearing drop, per the Rough Country kit (

$30 1776BOX1 Rough Country Carrier Bearing Drop Kit for 2005-2023 Toyota Tundra - 1776BOX1

1776BOX1), using 1 of 3 stackable shims.


driveline angles are not back to stock but are much closer and my vibrations appear to be solved. Thank you all for the help!