Basics on How to Adjust Pinion Angle

[Birdman]

How to adjust Pinion angle



Helpful Video




Measuring Pinion Angle


Pinion angle is the difference between the centerline of the driveshaft and the centerline of the pinion shaft of the differential. To measure it you must be able to work under the car with the suspension fully loaded and the car level. A drive-on lift works best for this.
Method "A" - (recommended)


Method A (recommended)
Use an angle measuring gauge (adjustable protractor) to measure the difference between the pinion flange and the drive shaft directly. These gauges are available for under $10 from a hardware store. Place the edge of the gauge vertically against the front of the pinion flange, beside the driveshaft. Extend the measuring arm forward parallel to the bottom of the driveshaft. Extend a straight edge under the driveshaft to the measuring arm of the angle gauge. Hold the straight edge flat against the bottom of the driveshaft and adjust the measuring arm to read the angle. Depending on the gauge you use, you may have to subtract 90° from your reading to get the correct number. Your final measurement should be between 0 and 5. Examine the diagram at the bottom to determine if the pinion angle is nose up or nose down.


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Method "B"


Method B
1) Use a gravity angle gauge (Available at hardware stores) to measure the angle between the driveshaft and the ground. Hold the gauge on the bottom of the driveshaft. Align the gauge front-to-back under the car in line with the driveshaft and read the number from the gauge. Write down this number.

2) Next, hold the side of the gauge against the front of the pinion flange (beside the driveshaft). Measure the angle between the pinion shaft and the ground. Write down this number.

3) Subtract the first number from the second number. This is your pinion angle. Examine the diagram at the bottom to determine if the pinion angle is nose up or nose down.

[Gr8snkbite]

great post...

[Birdman]

[Iceman]

they made the install of that upper mount look a lot easier than I remember it :)

[Birdman]

they made the install of that upper mount look a lot easier than I remember it :)

Adjusting the pinion angle is not too difficult but it is also not quite as easy as they make it look either but it is a good video.

[HSURB]

This is excellent information for people adjusting ride height.

HSURB®

[Gr8snkbite]

This is excellent information for people adjusting ride height.

HSURB®

Yep, and only really useful to those that lower the car, and/or change driveshafts. But lowering the car with a stock driveshaft doesn't really require adjustment.

[Little Debbie]

this spurred a nice conversation

[Vette Killer]

Great info, thanks for sharing...

The one piece I thought they missed was to have someone of the same weight as you in the driver's seat (or you can use barbell weights) when doing this (unless you are a scawny 12 year old girl...lol) and a 1/2 tank of fuel as it does make a difference....a lot of people overlook this step. 1/2 tank of fuel is a good balance point to cover average driving conditions.

I recommend spending a few more dollars and getting the digital inclometer; I set mine at -1.5 and it would have been at best a guess using the cheap dials, those are really meant for 1600 + up size drivershafts for transport trucks where you just need a reference not precision. When using the digital one it is important to add reference marks with chalk or metal marker to make sure you are going back and forth to the exact same spot and also important to use some crocus cloth or ultra fine steel wool to clean the area before starting to make sure there are no minor burrs or dirt etc. Just for perspective, at -2.25 I had a pretty bad vibration from about 100 to 125 MPH, at -1.5 there is a very slight one from about 110 to 115 MPH and was the best I could get it with the 1 piece aluminum shaft.

[Birdman]

VK...Good points about the weight and making sure the angle guage is in the same reference spot ...!!