Drive Shaft Vibrations Solved Step-by-Step

Just downloaded the app and I'll be checking the angles and reporting back. I did notice in the app it has three angles to measure, I'll measure from the TC, the aft DS and Rear Dif, and then again from TC, forward DS, and Rear Diff.

Truck did not have OEM shims. Dropped the OEM leafs, and installed the new leafs. Workmanship was pretty spot on, had the shop doing my alignment to double check my work and they found no issues on the install, as I always went back and double checked my work as I progressed on the install. Agreed on the 10.8 being very high, and it is definitely showing on the pedals and truck overall when slowing.

 

Did my best on using the app. The phone is finicky was placing. Did the best I could before I froze under the truck. Did the two measurements from TC, aft shaft, and Rear Diff; and then TC, Forward shaft, Rear Diff. Pictures shown respectively. FYI, not sure what the app is reading out to me to be honest. Did the measurements before winter storm hits tomorrow. I probably have to redo the measurements.

 

I haven't eliminated all of my vibes yet, but you have to start here and get the u-joints within spec.

 

Toyota replaced my driveshaft U joints under the SB warranty. The vibration seems to be gone. J

 

I think it might be time to remove my Street Tacos CB drop bracket. I used the Measure app in my iPhone to get the following:
T-case: 0*
FS: 10*
AS: 4*
Diff: 3*



That front shaft angle seems pretty extreme, and it is forcing the shaft down inside the carrier bearing quite a bit.

 

I forgot I had bought that street tacos bracket until I just saw this. never ended up putting it on. still brand new in the box.

 

Way too much.

 

Alright, got under the truck today and pulled out the Street Tacos CB bracket. I also decided to take some measurements with different setups while I was down there.

"Factory" configuration:
T-case: 0*
FS: 3*
AS: 8*
Diff: 3*

OME spacer:
T-case: 0*
FS: 4*
AS: 7*
Diff: 3*

OME spacer plus 2 washers:
T-case: 0*
FS: 5*
AS: 7*
Diff: 3*

The Measure App on the iPhone doesn't do decimals, which I think why the AS measurement didn't change between OME Spacer and OME Spacer+2Washers (rounding).

I went with the OME spacer plus 2 washers for now, and I rotated the CB 180*.

A test drive showed a massive improvement in vibration reduction. Freeway speeds, take off shudder and deceleration shudder (usually between 20-30 MPH) are all nearly gone now. Looking at the difference in angles though, wondering if I should pull the washers? That would put the "T-case to FS" angle difference at 4* and the "diff pinion to AS" angle difference also at 4*.

Ideally I think a 2* or 3* axle shim to get the diff pinion angle matched to the T-case angle would make it butter-smooth. But for now, this will really help and might keep me from wanting to push it off a cliff......

 

Which app are you using?

 

Built in App on iPhone called "Measure", part of iOS 12:
https://support.apple.com/en-us/HT208924

 

Use this:

http://www.tremec.com/menu/tremec-toolbox-app/

 

I have that app, and can't figure out how to account for the 4 different measurements that need to be made. It only supports 3 measurements, and with the carrier bearing and 2 piece driveshaft, there is no way I can see to make it work.

It will also automatically "fail" any u-joint angle that exceeds 3*. It is impossible to have no more than 3* for any u-joint in a lifted application on the Tacoma. Hell, the factory angle between t-case and carrier bearing is 3*....

 

I made sure first shaft was good, then used it as a baseline.

 

I've been reading up on driveline angles for 2 piece shafts and one way to solve it is to have all three working angles equal the same whereas the solution in this thread seems to be getting the middle working angle close to zero (angle between the two shafts) and then getting the TC/front shaft working angle equal to Pinion/rear shaft working angle. Has anyone tried getting all three the same?

 

Still no vibes since I upgraded my valve body and flushed the trans. Just sayin'.

 

That center CB looks wasted. That in itself can cause vibration.

 

How much was the valve body?

 

Coming from someone who spent hours taking angle measurements and tried just about everything to solve a driveline vibration after lifting a Tacoma, just bite the bullet and replace the rear drive shaft with a one piece. Trust me, you guys will thank me later.

 

Not an option for a DCLB.

 

Fair enough, but you can always add a second cardon joint to the two piece.