It looks like in both pictures, the trans is angled down and the pinion is angled up, but the pinion in the second picture is mounted higher than the one on the first pictures. That makes it look kinda confusing. The way I understand it, both pictures show pinion up (degrees above a flat line, or pointing upwards) and trans is pointed down for negative degrees.
That's the way I see it too. What I get out of it is, that it doesn't seem to matter how higher or lower the rear is in relation to the transmission but that the angles still have to be the same.
Pinion angle should always be in relation to the drive shaft, not the ground or "level". In both pictures, the line connecting the trans to the diff is representative of the drive shaft. It just so happens to be horizontal in the 2nd one. You'll see in the first pic that the horizontal lines are dashed and for reference only, as the angles for the tailshaft and the pinion both reference the drive shaft. So, in the first pic, the pinion is 3 degrees down in relation to the DS. In the 2nd pic, the pinion is 3 degrees up in relation to the DS.
that is my understanding also... so to set the pinion angle you first need to know the transmission/motor angle. my first reading was...motor...down 3...pinion...down 1.3... i then set it...motor...down 3...pinion...up 3.2...(added 4 degree shim) any suggestions???
Oh, and grease your u-joints first before you take off on a 300 mile trip. That reminds me, I haven't greased my new one!!! EDIT-- Just ordered that grease gun needle from Amazon that I asked about a few weeks ago. Glad I havn't driven the car.
Are those in relation to the drive shaft or to level? I'm guessing they're to level? If so, what is the driveshaft angle?
if you put gauge on tranny output shaft with driveshaft removed (flat part facing rearend) gauge will read app. 90` On rearend put gauge on yoke flat spot beside the u-joint cap. gonna show app 90` subtarct 90 from each # and you,ll have each angle. ie. 93- 90 = 3 ,,, 86 minus 90 = neg 4 Now I need my cheat-cheat(no sleep n I dont trust head so I use facts on paper) but you work those 2 numbers an have pinion angle. Your 2 diagrams from currie n inland are correct. For a streeter I have no idea other what manufactors say for a good angle. Good Luck.
You also need to put the gauge on the driveshaft with it installed. The angle that the tranny and pinion make with level don't help much if they're not on the same plane. For instance, a lifted 4x4 can have the transmission 3 feet higher than the rear end with the drive shaft at a 30 degree angle to the ground. While not as dramatic, if the trans is 2 inches higher than the rear end, it changes the angle of the shaft to the pinion.
The idea here is to make sure that the transmission output shaft and the differential pinion shaft are parallel to each other. As long as the drive shaft is more than 3 degrees and less than 10 degrees from level you will be fine. If you experience enough wrap on the springs to move the pinion angle more than 1 degree then you need to stabilize the differential with ladder bars or multi-link suspension.
this is from a link Jeff sent me...:Handshake Jeff Quick Performance... The typical leaf spring rear suspension will need 5-7 degrees of negative angle. You never want the rearend setup with positive pinion angle. This is when the yoke of the rearend is tilted upward more than the driveshaft. This can lead to binding of the u-joints and will hurt traction and break driveline components. ......
Pinion snubber is also a cheap and easy way reduce pinion wrap. Basically a bump stop for your diff. However, it doesn't help with reverse wrap that occurs when the car decelerates. That is why everyone should just install an Independant Rear Suspension. No fuss, no muss...
I like it! no fuss... that means you will be footing the bill, right? no muss... That means someone else makes the installation? Wow! thanks ATOMonkey! tiphat::bananaman