barnett468

for a street car you are only concerned about the pinion angle while you are at steady throttle at 70 mph . . when you floor it, the pinion will TEMPORARILY rise above the steady throttle position.

set it so it is 1 to 1.5 degrees below the trans angle if possible.
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guitarman376

Alright so I was finally able to remeasure my angles, here's what I got. This is with the car not perfectly level but with cars suspension loaded, so my understanding is measuring this way is fine.
Yolk angled towards ground at 6.5 degrees
DS angled toward ground at 3.5 degrees
Pinion angled up 1 degree


<a href="http://s411.photobucket.com/user/guitarman376/media/DL.png.html" target="_blank"><img src="http://i411.photobucket.com/albums/pp195/guitarman376/DL.png" border="0" alt=" photo DL.png"/></a>

I do realize that the up/down part of this measurement gets confusing, but I think you know what I mean. I attached a terrible diagram to illustrate my situation though.
This leads me to believe I need to shim the pinion upwards in order to have equal and opposite angles. Does that sound/look correct?

guitarman376

Would love some input on this fellas, I need to order the leaf shims (if I go that route) before bad weather arrives. I believe I need to either shim the transmission up or the pinion up. Let me know what you think please, I am new to driveline angle setup and have watched the videos etc

69mach1377

I went thru this a while back and concluded that my driveshaft was the cause for nasty vibes at 75-85 mph. A new 3.5" Denny's aluminum shaft did the trick after messing around with pinion angles for a while.
In order to get the rear of my tranny up, I would need to cut my tunnel, which I am reluctant to do.
Are you having any issues in particular?

guitarman376

I had what seemed like wheel hop happen when I went WOT from a stop on an off-camber street. Like power was reaching the ground funny. Since the front and the back suspension has been changed so much, I figured that driveline angles were worth measuring. I have never had a problem before, and I know the DS is phased properly.

Measuring the transmission yolk angle was not easy. I really wish the DS could detach from the yolk easier so that I could measure it easier, but I do think my measurements were good.

I might start driving it more once I get a new battery, just to see what its doing and when exactly. Once was freaky though, and from a measurement standpoint it does seem to be off some. If theres room to put washer underneath the tranny mount I'm going to try that, should make the 2 angles more even...

69mach1377

You would need a lot of washers based on my earlier calculations below;
If we could drop the engine down 1/2", it would give us less than a degree (.84*= inverse tan (.5/33.94)). Multiply that by 2 if we could also raise the trans 1/2".

guitarman376

'Multiply that by 2...' I don't understand that last part. If washers won't do it then I'm stuck ordering pinion angle shims.

Does anyone out there have an easy way of measuring transmission yolk angle? I had to use a square block and pull the trans yolk out a bit (1 1/2") to get a reading, but I would like to get a reading with the yolk sitting where it's supposed to if possible. My front u joints did not look easy to disassemble like the rear one is.

barnett468

.
i already answered your question.

69mach1377

Each 1/2" rise of the trans mount, or 1/2" drop of the engine mounts will give .84 degrees, so if you do both you'll get ~1.7 degrees out of it.

guitarman376

Thanks 69 appreciate the information. I am wondering which angle shims to buy, because I realized that when I change the pinion angle it will change the DS angle too. From my #'s I am thinking I need 4 degree approximately, but I have no idea how much the DS angle is going to change. That makes the shims I need a range from 3.5 to 4.5 degrees without knowing. Is guessing the only way? Hate the idea of having to dis/reassemble leaf packs TWICE!