Pinion angle help

[F4R/T]

Phasing was something you worry about when you have multiple shafts in line to make sure each one cancels out the other. If I’m not mistaken.

 

[VANDAN]

Mine is nuetral now, after assembly, so I was told to add 3* shim, at axle plates, for proper opinion angle. Any comments ? Thanks

 

[RemCharger]

Phasing was something you worry about when you have multiple shafts in line to make sure each one cancels out the other. If I’m not mistaken.

Correct. The only way to "un phase " a one piece driveshaft is to cut an end off and weld it back on incorrectly .

 

[olblue68]

took lowering blocks out, vibration still there

 

[69 Sleeper Bee]

took lowering blocks out, vibration still there

Are you saying you put it back exactly the way it was when you found it when the tail end was too high ?
I see you said it had helper springs which would have been added and you put them back in ?
Got any pictures of your trans. mount ?
More pictures the better of all mounts.

 

[Lefty71]

took lowering blocks out, vibration still there

Lot of possibilities, hard to diagnose over the net.... my gut says take a hard look at the front yoke. Also, no rust or damage with the rear yoke? May have to pull the rear ujoint to look.

 

[furyus]

First, does it vibrate when in neutral, or park? If so, you're looking in the wrong place.
If it does not vibrate in park, as was already said, download the tremec app. I used it on my truck, and it worked awesome.
Unless the car was seriously screwed with, the trans angle should be fine.

 

[INTMD8]

Appears you are taking measurements and running it on jack stands that are on the chassis and not the rear end.

Correct?

I would put jack stands under rear end and front k-member or control arms and re-check angles as it sits when driven.

It may have been mentioned but are the u-joints very smooth to rotate?

Many times after replacement and install of retaining clips you need to tap the caps back out so they aren't binding on the center cross.

Also, of course make sure they are the right size/tight fitment and proper clips to tightly locate it in the yoke.

 

[olblue68]

Are you saying you put it back exactly the way it was when you found it when the tail end was too high ?
I see you said it had helper springs which would have been added and you put them back in ?
Got any pictures of your trans. mount ?
More pictures the better of all mounts.

didn't reinstall helpers so it still sits a little lower, I find it hard to believe it is off now but vibration is still same so I guess it is

I will take some pics

 

[olblue68]

Appears you are taking measurements and running it on jack stands that are on the chassis and not the rear end.

Correct?

I would put jack stands under rear end and front k-member or control arms and re-check angles as it sits when driven.

It may have been mentioned but are the u-joints very smooth to rotate?

Many times after replacement and install of retaining clips you need to tap the caps back out so they aren't binding on the center cross.

Also, of course make sure they are the right size/tight fitment and proper clips to tightly locate it in the yoke.

everything is good with u joints, the vibration is the same as with the old driveshaft

 

[olblue68]

First, does it vibrate when in neutral, or park? If so, you're looking in the wrong place.
If it does not vibrate in park, as was already said, download the tremec app. I used it on my truck, and it worked awesome.
Unless the car was seriously screwed with, the trans angle should be fine.

will try the app

 

[747mopar]

What do you mean by "phased correctly"? Flip it 180 in the pinion yoke I am guessing? I have never heard anybody having to do that with a balanced driveshaft.

The yokes have to be perfectly inline on a driveshaft, not something you can change without cutting the yokes off but it will cause major problems. Watch the video that I posted below, phasing it's at the end of the video.

 

[747mopar]

I fought this, tried all of the recommended angles with no luck. There is no absolute angle because not every spring behaves the same for instance a weak spring will climb more under acceleration than a stiff spring so the best thing you can do is understand what's going on and adjust accordingly. Some tests while driving it will point you in the right direction, get the car up to speed where the vibration occurs then get on the gas hard, next do the same only let off the gas.. if the vibration lessons while on the gas shim the nose up and if it lessons while coasting shim down. Although that sounds simple this gives you no idea how much you need to shim, it took me a couple tries shimming more and more but it did correct the issue. In my case a suspect the aftermarket springs are just to soft or possibly bent incorrectly throwing the angle off?

 

[747mopar]

I've posted this video before but it gives you a really good look at what all goes into a smooth running driveshaft.

 

[olblue68]

Here are the numbers

 

[INTMD8]

Is that with the car supported by axles or chassis?

 

[olblue68]

Is that with the car supported by axles or chassis?

all weight on suspension as if it was on the ground

 

[beanhead]

If the transmission is pointing up 3°...
I'd be correcting this before addressing the rear. I'd want to get the transmission shaft centerline pointing down at least a half a degree, then go from there.

 

[olblue68]

Trans is down 2.8 rear is up 3.1

 

[beanhead]

Okay I see I mis-read what you stated in the first post...so then it's easy. Do whatever you need to do to get the pinion to point down approximately 1 degree at rest. The factory perch locations *should* allow this with no problem. We want the angles parallel and opposite under power, but in the real world as long as they're close to that it won't cause problems.