Pinion angle help please. In the middle of setup
07-04-2009, 10:24 AM
#1
Pinion angle help please. In the middle of setup Car is sitting on rhino ramps all 4 corners. Heights are set. I am using the Midwest short arm setup on the second from the bottom hole up front. I am using a smart level. If I put on the tailshaft housing and zero it out and then put it on the bottom of my 9 inch I get 2* negative pinion/housing from driveline angle. Seems right. The part that keeps fing me up is if I put it on the back of the d shaft and zero then put it on the housing it shows a working angle of .2* positive. WTF am I doing wrong. Help would be greatly appreciated as I am in the middle of setting everything up now.
07-04-2009, 11:00 AM
#5
Maybe if I were to put the front of the tq arm in the lowest hole up front I may get closer but with it in the 2nd from lowest hole there is no way I can get it to read that. That is why I started with the tailshaft that way I knew exactly where the car was sitting and zeroed it off of that point and then I get 2.0* neg on the pinion with a positive working angle.
07-04-2009, 11:25 AM
#7
The way I understand it is to put a protractor on the driveshaft and find the degree of the angle of the driveshaft then subtract 2* from that. Then set your rearend at that degree of angle. Example - if ds is +1 degree then +1* -2* = -1* Most ds are on a positive angle to began with.
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07-04-2009, 03:25 PM
#11
That would be correct. I'm still trying to set mine up also, I just got some DA LCA's from Eric. Looking from the passenger side, my ds is running downhill from the transmission which is a positive angle. My ds angle is +1*. So I need my rearend looking down -1* at the yoke. That will give me a -2* driveline angle. So when you take off the rear will raise up +2* and be inline with the ds. So your ds and rearend will be straight inline with one another. I think alot of people just set their pinion angle at -2* and leave it but I want my driveline angle at 0 when hard on the gas. If I'm wrong someone please correct me.
07-04-2009, 04:59 PM
#14
What screws me up is that the actual pinion or yoke is positive and not pointing down hill but up slightly. But in relation to the driveline that would be correct from what I have read and the diagrams I have seen. This way on the gas it comes up and is 0. It is extreemely confusing and I keep going out to the garage and checking and adding numbers and then I half to come back in and clear my head. Thanks for taking the time to help out guys.
07-04-2009, 07:07 PM
#15
Took another set of numbers. This time off the crank pulley using a small square. It read 4.6* I zeroed the level and using the square on the face of the housing it reads
1.7* negative in relation to the crank. Even though the actual pinion is at a positive angle. If I roll the rear higher positive it would lower the 1.7 number taking working angle out of the driveline. If I roll the rear down that would put more angle in the driveline.
1.7* negative in relation to the crank. Even though the actual pinion is at a positive angle. If I roll the rear higher positive it would lower the 1.7 number taking working angle out of the driveline. If I roll the rear down that would put more angle in the driveline.
07-05-2009, 10:42 AM
#16
This is very confusing and you get alot of different answers from people. But if your at
-1.7* I would say that is pretty damn close. My rearend is also running uphill at 3* and my ds is at 1* so I need to lower my rear by 4* to get a -2* driveline angle. I hope with the DA LCA's I can do that. Yeah I been under my car a hundred times looking at this. And it's still confusing as hell.
-1.7* I would say that is pretty damn close. My rearend is also running uphill at 3* and my ds is at 1* so I need to lower my rear by 4* to get a -2* driveline angle. I hope with the DA LCA's I can do that. Yeah I been under my car a hundred times looking at this. And it's still confusing as hell.
07-05-2009, 08:51 PM
#18
If your trans is running downhill then your rearend will be up hill. Where ever the myth came to be that the rear end must point down 2 degrees from "ground" no matter what is only true if you want to break a u-joint and have the driveshaft come through the floor. What if the car is slightly up hill 2 degrees? then the pinion is down 4 degrees.
most production cars have the crankshaft hight higher then the trans yoke.
what ever this degree is, lets use for example 3 degrees down(as in the transmission running down hill front to back). The yoke on the rear end must point up 3 degrees to cancel out the angle. From there you drop the rear end yoke 2 degrees down, which means the yoke is still pointing up 1 degree.
Now in a tube chassis car, most of the time the transmission yoke is higher then the engine. In this case the rear end yoke will be pointing down.
If I need to draw a diagram out I will if it helps with any confusion.
most production cars have the crankshaft hight higher then the trans yoke.
what ever this degree is, lets use for example 3 degrees down(as in the transmission running down hill front to back). The yoke on the rear end must point up 3 degrees to cancel out the angle. From there you drop the rear end yoke 2 degrees down, which means the yoke is still pointing up 1 degree.
Now in a tube chassis car, most of the time the transmission yoke is higher then the engine. In this case the rear end yoke will be pointing down.
If I need to draw a diagram out I will if it helps with any confusion.
07-05-2009, 09:06 PM
#19
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If your trans is running downhill then your rearend will be up hill. Where ever the myth came to be that the rear end must point down 2 degrees from "ground" no matter what is only true if you want to break a u-joint and have the driveshaft come through the floor. What if the car is slightly up hill 2 degrees? then the pinion is down 4 degrees.
most production cars have the crankshaft hight higher then the trans yoke.
what ever this degree is, lets use for example 3 degrees down(as in the transmission running down hill front to back). The yoke on the rear end must point up 3 degrees to cancel out the angle. From there you drop the rear end yoke 2 degrees down, which means the yoke is still pointing up 1 degree.
Now in a tube chassis car, most of the time the transmission yoke is higher then the engine. In this case the rear end yoke will be pointing down.
If I need to draw a diagram out I will if it helps with any confusion.
most production cars have the crankshaft hight higher then the trans yoke.
what ever this degree is, lets use for example 3 degrees down(as in the transmission running down hill front to back). The yoke on the rear end must point up 3 degrees to cancel out the angle. From there you drop the rear end yoke 2 degrees down, which means the yoke is still pointing up 1 degree.
Now in a tube chassis car, most of the time the transmission yoke is higher then the engine. In this case the rear end yoke will be pointing down.
If I need to draw a diagram out I will if it helps with any confusion.
07-05-2009, 09:18 PM
#20
Thanks guys. That is what I was thinking but then I keep seeing sponsors saying the pinion must point 2* down. There is no way I have that much adjustment left in my tq arm adjuster. Even if I did there might be a thread on both sides left. I do know for sure that isn't right. I am even in the 2nd from bottom hole in the front tq arm mount. I have had some pms regarding the -2* pinion down method from the ground and was told it worked like NOT GOOD. I have mine set at -1.5* and I will drive it to make sure all is good. If I can get it to -2* with out vibes I will but thought 1.5 was a good starting point. This has been very informative to say the least. Thanks again that is what I was looking for before I locked all the lock nuts down and got it back down on the ground. Thanks again.