driveline angle corrections when lifted " the light fix"

I know there has been tons of discussions on this and its been beat to death but as a newbie on here, I have a simplistic way of wanting to look at this.

My 2016 TRD Offroad has been lifted 3" in the front with spacers and stock shocks which I guess I need to change and, spring blocks for the rear raising it up 2" in the rear once again stock shocks that seem to barely be long enough.

When I look at the DS Angle, clearly it needs correction.
I read a very comprehensive forum article on how to measure and correct this with wedge shims, etc

Problem I have is that I do not want to raise the rear of my truck up ANY amount at all.
If I use those wedge shims, I will be changing the angle AND raising it up a bit more any way you slice it. Im guessing even a small correction will add 1/4" or more right?

Also with my kit was included a " differential drop" however that works and whatever it is, my shop could not figure out how to mount it as there were no instructions so they left off the couple long bolts and spacer that we assume was the "differential drop"

Let me ask this, while it may not be perfect, it looks to me like simply dropping the carrier bearing down some with some small shims will go a long way toward at least improving the angle and kind of splitting the angle up some between the two shafts.
It wont be perfect but it has to be better.
Even without an exact measurement, anyone can eye it and see improvement just by loosening it up and letting the bearing hang down some as the angle becomes less.
Just seems like it would work to get it close.

 

Uhh yeah, that's what most people do. I guess you didn't read very far into those discussions on what to do for drive shaft vibes. Carrier bearing shims and/or axle shims are what's used to fix the vibrations.

Differential drop goes to the front diff. I would seriously question the shops work if they couldn't figure that out.

 

My question was if a 2 inch raised rear could be gotten close enough just with bearing shims and not using the axle shims

 

dropping the csb is used to fine tune your vibes. It's best to not have to drop it at all so you have a straight line as possible coming out of the transfer case.

get the working angles between the 1st and 2nd drive shaft to match the working angle between 2nd and diff pinion. this needs to be done with angle shims if you're actually wanting to correct the angle.

don't worry about the extra 1/4". I'd have to visualize, but it's rotating your axle so it's not going straight to ride height. put a sandbag in the bed.

 

+1

 

When adding a lift , you have no choice but to cancel your angles properly .
All you need is a cheap incline-ometer
Have a look at what the 2nd gen guys are doing
CANCEL DRIVELINE ANGLES http://www.tacomaworld.com/forum/2nd...tion-free.html

 

I installed a one piece CV driveshaft on the rear of my lifted f350 and it was the only thing that stopped all of the vibrations.

 

This info is key. Im about to start my build next week. Putting in OME 887s and dakar w/2nd gen 5100s. Info here is much appreciated!

 

Update guys.
I bought a nice meter to measure what going on so let me give you some angles and for those who understand these angles, I'm hoping this sheds some light on the issue with the vibration that is happening during braking and coming to stop only while in gear and once put in neutral, all vibrations are gone.

I took the measurements in both degrees and % of incline, here we go:

Front shaft = 10.14 degrees / 18%
Rear shaft = 8.70 degrees / 15.3%
Front output flange = 3 degrees / 5.5%
Rear differential flange = 5 degrees / 8%

Also interesting and something I don't like, when I measured the side-rail of the bed to verify a suspicion of mine it was confirmed. the front of the truck is higher than the rear. I don't like the look of this, it affects mileage, and makes it harder for a short dude like myself to see over the hood.
The measurement was .55 degrees / 1% incline front to back

This info is based upon having about a 1/2" shim under the carrier bearing bracket.
I am starting to wonder if this shim did not make things worse.

Note: background reminder: this gen 3 truck has a lift kit on it that is supposed to be a 3" front and 2" rear lift. FYI

thanks mike

 

It's difficult to understand measurements short of pics.

From what I can tell...
1st working angle is way too much at 7.14 degrees(10.14-3).
2nd working angle is 1.44(10.14-8.7), 'broken back'; big no-no.
Carrier drop is responsible for screwing these two working angles up.

Pinion working angle is 3.7(8.7-5) degrees.

Maybe this will help you some...

 

Good information thank you very nice. So from what you have said and the detail I would ask you this, when I lowered the carrier bearing it seems to have made some negative effect to the overall arrangement. By putting it back like it was it seems to me that we will be correcting the front shaft and putting it back into a less declining condition and presumably within spec but will that not make the rear angle even more prominent?. It seems like from the detail and from what you are saying this isn't really important. The overall angle of the second or rear shaft isn't really that issue it's maintaining the same degree of angle at each end relative to the attachment point or flange is this correct? If so I can go in and pull out those shims and immediately make the situation better I think. However it still seems to me like I would want to after doing that put some wedge shims in the rear to raise the pinion flange to reduce that angle or, am I getting myself right back into a mismatched rear by doing that.

Also please consider that I was looking forward to putting wedges under the rear Leafs anyway or doing something to raise the rear slightly even if a half inch because of the issue of having the front higher than the rear and having a problem seeing properly so if I were to use the shims in the rear that would change the pinion angle and put me back in a different situation where the carrier bearing drop may actually not be bad and compliment that is as possible?

While I realize that wedges are never used for the purpose of raising the rear it seems like they as a secondary feature do have some effect on raising it ever so slightly which was a welcome thing in my case please comment on this as well thank you

 

Taking the carrier drop out would lessen the first working angle and take out the broken back angle.
Yes it will increase the pinion angle; this is why most use angled shims under the leafs to equalize the middle and pinion working angles. In this case, you need to measure the rear shaft to calculate the middle and pinion working angles.

It is my understanding the 1st working angle is set from the factory in the 3-4 degree range; it would likely take a carrier bearing lift to get it in the 0-1 degree range. I suspect that's why even stock Tacomas eat carrier bearings.
You cannot equalize 3 single u-joints; one of them needs to have a working angle in the 0-1 degree range. It should be the first working angle, as in the diagram.
Unless you're willing to fab a carrier bearing lift to get the 1st working angle at 0-1 degree it will either eat carrier bearings and/or have some kind of vibe. Is what it is.

My cheap advice; take out the carrier drop bearing, re-measure the middle and pinion working angles and get the appropriate shims to equalize them.

My $ advice; at 3"/2" lift, length is probably affected...
Get a new shaft made; either a 2-piece with double cardan middle u-joint or 1-piece with double cardan output shaft u-joint. My personal leaning is torward the former.
These both require completely different set-up than a 2-piece/3 single u-joint driveshaft.

 

Agreed. This seems to be the case.
I think when I do this I will also measure the front again just so that I have a baseline on where it is and although it may not be perfect it's going to be back closer to the factory specs and as you say it will be what it is. As far as the rear is concerned yes that will also improve the rear issues but leave me with needing to insert the wedges in the rear in order to correct the pinion. So I'm guessing from what you've said that once I measure that resulting angle at the middle and rear of the rear shaft I will be able to extrapolate from that what the proper wedges should be. I'm not sure I know how to do that but maybe it's simpler than I think once those are known Dimensions front and rear there must be a calculation for determining that I will look back into that I guess and worry about it when that time comes in the meantime I will get that sham removed and get the carrier bearing back up higher than it is now preciate all the help thanks Mike

 

I spoke to a tech at spc alignment....he told me that on a truck with carrier bearing...the two angles that you need to have equal are the joint behind the carrier bearing and the pinion angle..since the joint between the transfer case and the carrier bearing does not move....

 

If you have access to a laser line, I would use it to measure any side-to-side alignment to account for compound angles. As is you're only accounting for up/down. String line would work too.

 

Did you put larger off road tires on your truck with this lift or do you still have the OEM tires on ?

You will feel alot more of the road with bigger tires and if they are not balanced right it can cause issues. This is where I'd start before I start playing with drive line angles of my $50g truck

 

Correct.
This assumes the 1st working angle is correct to begin with. I purpose that it is not. It actually needs a carrier bearing lift; a drop is just wrong.
Toyota screwed the pooch when they eliminated the double-cardan joint from 1st gen to 2nd gen.

 

yep i forgot to mention that...he said most stock trucks the front part of driveshaft are in spec, so adjusting the rear angles would be the way to get the angles equal. . when people mention carrier bearing drop then you are adding vibration by talking the angles out of spec

 

I'll also add; I've seen a few reports of driveshafts being improperly balanced from the factory, as well. Just another possibility to consider.

 

Guys this is all fantastic info and this is the great part about this community. The sharing of good information is invaluable.
So here is an update:

answer:
*yes I did change tires to 17" wheels and tires that are SLIGHTLY taller than stock but NOT by much and they are all properly balanced.
* No I did not check for side to side misalignment but as I think of it, I am wondering what would possible account for this? is this not a factory set alignment of the tranny back to the differential, anything I could have done to change this, doesn't seem like it?

UPDATE NEW INFO:
So, I just pulled the carrier bearing drop out of it and its back to stock. I re-measured the new angles AND I took it for a test drive. The vibration I was having during braking and coming to a stop is reduced by probably 70%. I only feel a very little bit of it now, much improved!.

here are the new angles and from this, I'm hoping we can determine the correct amount of shimming for the rear leafs to correct or improve the pinion angle mismatch.

Front drive shaft angle along its length: 7.7 degrees
Rear drive shaft angle along its length: 9.35 degrees
Rear flange angle at differential: 4.3 degrees
Middle Flange angle at carrier bearing (front of rear drive shaft): 7 degrees nominal
Front Flange angle at trans. : 3 degrees

Splitbolt, how does this new measurement improve upon the first one and any ideas as to what is needed under springs to improve it?
mike