3rd gen lifted up and angle my shaft, baby!

OK, so after much "research" on lifts and appropriate prop shaft angles and the like after I installed 6" RCD lift on my 2020 SR5 DC AT, of said lift were included some big f#** off spacers. According to RCD, these spacers were to bring the angles of the u joints back in "harmony". K, but I was under the impression that on these 3 piece props since there are only 3 u joints, 2 of which (rear diff shaft and its partner) that can load and unload properly to "balance" out the load. Thus leaving the 1st u joint (coming out the trans) essentially without a u joint partner. And because of this, you have to use the output shaft angle as the opposing u joint, i.e. the a angle of the output shaft has to be maintained with that first part of the prop ( carrier bearing). If that's true, than unless the transmission is moved for whatever reason, that the carrier bearing shouldn't move either unless you want to wear out output shaft/ transmission parts. And since the lift I installed only dropped the front diff, transmission/ tranfer case wasnt lowered or moved from stock, then the only way to properly make up any shaft balance/ angle issues HAS to be made up in the back half/ AFTER the carrier. The reason I ask is that I went ahead and installed the spacers and low and behold under deceleration at anything over 30mph I would get a vibration. I even stupidly put even larger spacers in for a very short time thinking that BOTH parts of the prop shaft were supposed to be in a straight line from output shaft to diff! This was before I actually read up on shaft angles and unloads etc and after I quickly removed ALL the spacers. Once all were removed, and carrier was back in her stock location, vibration has been gone. My question is, well, is this correct or am I truly confungled? Any help would be greatly appreciated, gents! Aloha

 

I don't understand a word you said.

 

Photos are worth 1000 words….

 

I feel like you need to take pics of the spacers that came in the kit. My 2.5-3" toytec lift uses spacers when i get off work later this week i can take a pic and send it to you so you can see how they are installed.

 

OP would have had to post 1000 pictures to make up for the 10's of thousands of words in his post...

 

Really? Pics? I wasn't asking for anyone to look at my set up. I was asking whether or not my understanding of how balancing a drive shaft is done is correct. My understanding- A u joint uses the opposing u joint for balance- one should be unloading while the other is loading, correct? This is where the angles come into play for canceling workloads. Now, If you look under your truck, you'll notice that there's 3 u joints (on the rear drive shaft, not total, smart asses). So that means somebody doesn't have a dance partner. The front u joint (From the transmission) is acting essentially on its own
In order to "balance" it, the carrier bearing is placed at a height that maintains the "angle" from the output shaft thru the 1st u joint, "balancing" it. And if this is true, (which was my question- ) then the carrier shouldn't be moved period unless the trans gets moved (idk why you would move the tranny, but I digress). Is my logic correct or do I need to take some pictures?

 

Again, I have no clue and I'm an engineer.
The torsional force of all of your driveline is either loaded or unloaded. The forces are equal. Give it the gas, everything turns with the same torque.
I just re read your post for the 3rd time. Still don't understand.
The reason for the angles is simply slip distance for your suspension to cycle so there is no binding.
I've done a lot of driveline vehicle calcs and balancing a u joint against another one must be PhD level engineering. We just calculate the torque, slip and bind angles and don't go there. I bet NASA could learn from your post.
I just checked driveline docs and didn't find anything like you talk to in your post. Maybe I am just not smart

 

If you have a 6inch lift there should be a spacer for the carrier bearing. At least there is on my f350 with a 6in lift. Weights on a driveshaft is what balances a driveshaft not u joints. Plus without the spacer the angle will be to great and the slip yoke will be extended probably close to the limit.

 

That's why I also asked if I had read too much into this and am now over thinking it. And the reason I was asking about my logic was after the lift and spacer, i got a vibration in the shaft. So when I removed the carrier spacer and my vibration went away, this was where my logic was. And thus far it has been great, no vibrations or nothing. Not trying to over complicate this but i just may have done exactly that

 

Use an angle finder and plug in the angles in a driveline calculator. You can then adjust the Carrier appropriately.
Lots of good info on https://spicerparts.com/calculators/driveline-operating-angle-calculator

 

If it don’t shake as is now that it’s all confungled I’d leave it be.

 

Driveshaft angles are the main issue.
Tom Woods stopped selling his 1-piece driveshaft for Tacoma but his Tech articles are very useful in understanding what's happening:
Articles – Tom Wood's Custom Drive Shafts (4xshaft.com)
Tacomas have very weak rear springs that also are involved in the diff rotating up and changing the driveshaft angles and vibration. Lifting alters the whole equation of angles and vibrations.

 

I do not know anything about lifts, besides I would never buy a used modified vehicle, my reason, this tread.

But, this made me think of this LOL

 

My understanding is your pinion angle needs to match the angle at the rear of your carrier to cancel out.

 

You are not wrong.

I think others here are reading your post wrong because you used the words 'balance' and 'load' ("to balance out the load") when referring to each u-joint having a mating partner. Better might've been "to cancel out the vibration".

Yes, it is tough getting these two-piece shafts with carrier bearing to spin without vibration after a lift (even stock they vibrate quite noticeably).

What I'm wondering is why a company would stop making a one-piece shaft for a vehicle having such a widespread issue... Is it because the distance from trans (or t-case) to rear axle is too great and shafts were whipping out of balance? Maybe the answer is a double-cardan joint somewhere on the existing configuration (giving the 3rd u-joint that mating partner, as OP put it).

 

As to post 15 I believe Woods stopped due to his easy return policy and many Tacoma owners simply bought a 1-piece hoping to fix vibrations without ever looking at their stock soft springs as part of the issue or lifting and changing all the angles and then again a 1-piece and hoping for smooth ops - nope so they were returning too many of them and he was wasting a lot of money. In fact the DCSB is not too long but a DCLB was/is and all detailed on his site. He would take your call and discuss problems - a really good guy but times change and many have become Amazon return freaks so blew it for us all that have benefited from his product and help.