Adding Pinion Angle Shims - Tell Me If This Sounds Correct, Please
Just finishing my install of a Gear Vendors Overdrive and checking my driveline angles to make sure I end up with the correct specs under load.
First photo shows about 4.5 to 5 degrees down on the output of the overdrive and about 5 degrees up on the pinion angle.
I ordered some 3 degree shims from Doctor Diff to put under the perches on my 8 3/34 rearend which has the ESPO +1" leaf springs and an adjustable pinion snubber which is currently almost touching the floor pan since I flipped my front spring hangers upside down to lower the rearend a bit. I will cut the pinion snubber down so it has some clearance.
3 Questions:
1. Adding the 3 degree shims to bring the pinion angle down should wind up leaving my pinion angle me about 2.5 degrees down from center, at rest. does this sound right? Or will that be too much for mainly a street car and possibly cause a vibration at cruise speeds?
2. Before I measure for my driveshaft, I am installing some 3/8" shim blocks in the front spring hangers in order to move the rearend back a little to help center the larger tires in the wheel opening better.
This shouldn't really affect the pinion angle at all, or very very little, correct?
3. How much room should I leave between the pinion snubber and floor pan? My combo is a 340/416 stroker with 540 ft/lbs torque and 520 horse on the engine dyno. Currently running 3.73 gears but switching to 4.10 gears with the overdrive unit installed. Tires are 295/55/15 drag radials, so it hooks pretty well. This is mainly a street car but hoping to get it to the track on occasion once I have things dialed in better.
-Thanks for any input!
-Doug
Here's how I have the car sitting, all jackstands under suspension.
Just finishing my install of a Gear Vendors Overdrive and checking my driveline angles to make sure I end up with the correct specs under load.
First photo shows about 4.5 to 5 degrees down on the output of the overdrive and about 5 degrees up on the pinion angle.
I ordered some 3 degree shims from Doctor Diff to put under the perches on my 8 3/34 rearend which has the ESPO +1" leaf springs and an adjustable pinion snubber which is currently almost touching the floor pan since I flipped my front spring hangers upside down to lower the rearend a bit. I will cut the pinion snubber down so it has some clearance.
3 Questions:
1. Adding the 3 degree shims to bring the pinion angle down should wind up leaving my pinion angle me about 2.5 degrees down from center, at rest. does this sound right? Or will that be too much for mainly a street car and possibly cause a vibration at cruise speeds?
2. Before I measure for my driveshaft, I am installing some 3/8" shim blocks in the front spring hangers in order to move the rearend back a little to help center the larger tires in the wheel opening better.
This shouldn't really affect the pinion angle at all, or very very little, correct?
3. How much room should I leave between the pinion snubber and floor pan? My combo is a 340/416 stroker with 540 ft/lbs torque and 520 horse on the engine dyno. Currently running 3.73 gears but switching to 4.10 gears with the overdrive unit installed. Tires are 295/55/15 drag radials, so it hooks pretty well. This is mainly a street car but hoping to get it to the track on occasion once I have things dialed in better.
-Thanks for any input!
-Doug
Here's how I have the car sitting, all jackstands under suspension.