Carrier bearing drop?

At what point do you need to drop the carrier bearing? I have a rancho quicklift setup in front with about 2 inches of lift, and am stock in the rear. I am looking to lift the front more soon, as my truck just barely sits level and I like the front higher look. What point does it start messing up the carrier bearing? Had an old Ranger with a lift and that thing went out all the damn time and was a pain in the ass. Really don't wanna deal with it on this truck too

 

I would only use a CB drop if you mess with the rear.

 

Ok I was under the impression that if you lift the front and not the back then it messes up the angles. And if you lifted both the same it would stay in line but I suppose I wasn't thinking that through right

 

Here's the way to think about this.

When you raise just the front, since the body doesn't bend, you are pivoting it around the rear axle in the back. Since the carrier bearing is in front of the rear axle, it is being raised a bit, and since the rear axle is not moving, the angle is definitely changing. For the sake of discussion, say the carrier bearing is about 1/3 of the way to the rear axle, 2/3 of the way to the front. This means that for every 1" you raise the front by itself, you raise that carrier bearing by 1/3 of an inch. If you raise just the rear, then for every inch you raise, the CB raises by 2/3 of an inch. If you raise both by the same amount, obviously the CB raised by that same amount since it is still attached to the body/frame.

The greater the angle between two shafts connected by a single universal joint, the more irregular the motion becomes. Ideal angle is zero degrees. You can stand fluctuation up and down on bumps. Not so much on straight and level driving. That leads to vibration.

If you measure accurately, to determine exactly how far the carrier bearing is from the front and rear axles (my number was just a guess to make the explanation work) then you can figure out what you need to do. But if you raise anything, the optimal path would be to lower the CB by the amount calculated as above. Then you stay in the stock configuration. It might be that you can get by without dropping the CB, but you are certainly increasing the angle, and vibration is not that far away. And might even already be present, you just don't yet notice it.

I've built a couple of hot rods where we dropped in a foreign engine/tranny. That makes for a LOT of fun. Sometimes it will only fit if the tailshaft of the tranny droops a bit. There's an unwanted angle. A Cardan joint (i.e. a double u-joint or something similar as used in CV joints) solves this, but they are not as cheap. That's why they call them CV (or constant-velocity). They don't exhibit that irregular speed on one side as the other rotates while the shaft is at an angle.

That whole thing on the Taco seems to be an ill-conceived idea, one that was created at the last minute to address a problem that was overlooked until right at the last minute.

A one-piece drive shaft has the same problem if you lift, since you are screwing with the angle at the front and at the back at the same time.

 

I don't have a carrier bearing drop. I have a 1.5" aal with a small degree shim in the back and coilovers in front set just under 3". I have zero vibes or issues. I also had Bilstein 5100s on my old 2005 Tacoma set at .85 and then at 1.75 and no rear lift. Never had issues with it either and i didn't have cb drop.

 

LOLOL are you seroius?

Raising the front alone does NOTHING to actual driveline angles in the rear. It simply moves the driveshaft a little further off the ground. as the truck is now sloped more upwards at the front. THE ONLY driveline that is touched by raising the front are the angles of the front CV joints at the hub and front diff.

By your logic simply putting blocks of wood under the front tires or going up a hill would mean the rear driveline angles are changing.

Nice try though, love the troll logic.

 

Sorry, but try again. If you raise the front by N, you raise the midpoint by N/2 and the point above the rear axle by 0. Believe what you want, but the pinion angle WILL change when you raise any part of the truck, because the driveshaft does not move, but the body of the truck certainly gets higher. Unless, perhaps, if you cut the body between the bed and cab of course.

Didn't say a THING about a block of wood under the front tires, numb-nuts. I said "raise the body with respect to the driveline". If you put something on TOP of the front axles, so that the front bumper is higher, yet the axle is the same, you just changed the driveline angle. There is NO way around it. You simply need to read and THINK first. One end of the drive-line is the rear axle that does not move. When you move the engine/tranny that is attached to the frame, WHAT happens to that carrier bearing attached to the body in the middle of the back? Is it NOT going to raise somehow? Body goes up, CB goes up. Angle between driveshaft and pinion and carrier bearing will change. Angle between CB and tranny won't change, but the other side WILL. That will cause vibration. Whether it is noticeable or not is another issue, but it will be there the further you depart from 0 degrees.

Feel free to give me a simple geometry lesson on how you are going to shift the body but leave the wheels on the ground, and not see that angle shift. It certainly will be far less significant than when raising the back, but it is still there.

 

How, EXACTLY, do you raise the rear axle? Bigger tires? That's not a "lift kit". Rear axle remains at same distance from ground unless you change wheel size. Not so the carrier bearing as you raise any part of the body.

 

It's pretty simple actually, just have to measure the angles at the transmission and at the carrier bearing, if they aren't pretty damn close, you'll need to add a shim. If you do that make sure you also measure the angle at the rear axle to make sure you are still within reasonable tolerances.

Watch this (lengthy) video that explains it quite well:
http://youtu.be/f1m-Fh5kiRU

 

Lol what?
The pinion angle may change if you are using level ground to measure the angle, but that is a useless number. That isn't pinion angle by definition. None of that matters. By your logic, pinion angle would increase as you park the truck on an incline. You should be measuring the angle between the pinion flange and the driveshaft. That does not change in the rear from lifting the front. All rear angles will stay the same relative to the frame and drivetrain.

It is like you aren't understand that when you lift the front axle, the rear axle DOES move. It would rotate pinion up a very small amount. Thus the angles all remain the same between pinion, carrier bearing etc.

 

WHAT?
Neither is a lift. I don't know the relevance to this statement but technically a different diameter wheel makes no difference to changing the axle height from the ground, the overall diameter of the tire does. You know, the big rubber part around the wheel.
And neither makes a damn bit of difference to pinion angle.

 

dude, get your shit checked, you are ALL sorts of wrong. By lifting the front like stated only the front suspension angles change, THATS IT. the engine, frame, trans, transfer case, rear driveshaft and rear axle all stay the EXACT FUCKING SAME relative to eachother, thus THERE IS NO WAY rear driveline angles could change. The only time rear driveline angles change is if you move the motor / trans / transfer case up or down within the frame, CB up or down relative to the frame, or rear axle up or down relative to the frame.

the below response is perfect....

 

I think the part you are missing is that the rear axle is hard mounted to leaf springs which are hard mounted to the frame so when you lift the front end the entire chasis and everything attached to it simply tilts up, frame, leafs, axle all tilt up with it therefore there is no change to the pinion angle. The only way the pinion angle would rotate as you are describing is if the rear axle was not mounted to the leaf springs.

 

this

 

Subd

 

So then when is a carrier bearing drop needed then?

 

X2. He fills my head so full of fuck when I read his posts, it's pretty comical.

 

only to try to make the angles ideal again, to reduce excessive wear or vibration from a more extreme angle, should you lift the rear

 

no to this.

when you raise just the front, the front cv's get a more extreme angle...
but that is it

when you raise the front, the engine, tranny, frame, and driveshaft all go with it, keeping all prop shaft angles identical.

you may have been trying to say something else, but what you did say is all sorts of incorrect.
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only if you raise the rear, and the body of the truck in relation to the rear axle changes distance, only then do you have new prop shaft driveline angles.