Pinion angle
 

Can someone please tell me how i measure the pinion angle i put spyders drive shaft on and have no idea how to measure degrees detailed instructions would be great i have bmr lca and relocation brackets also, so ill have to get a adjustable upper to set it but have no idea how to do this , does this have to be done i have no vibration or noise ,well the only noise i noticed is if the car is in first gear (manual) and i just let it idle i hear a little moan but its not that bad so any help would be great thanks [8D]

RE: Pinion angle
 

Hey bullit,

If you have a 1-pc driveshaft such as Spyders, then you can throw away the pinion angle directions that came with your LCAs. For a 1-pc driveshaft, here is what you do:

This is easiest to do with the driveshaft removed from the car.

1. Measure the angle of your transmission output flange with your angle gage.

2. Adjust the pinion angle so that the pinion flange has the same angle as the transmission flange. You want the two to be paralell.


Does it have to be done? That is a loaded question my friend. Is you car going to explode if you don't do it? No. However, if you drive the car without properly setting the pinion angle for your 1-pc driveshaft, then you can expect noise, vibration, and increased wear of the driveshaft U-joints as well as your pinion bearings in the rear end.

RE: Pinion angle
 

Hey, would it be worth the money to do the 1-pc. carbon fiber driveshaft? I do not see any more than 450 hp in the future.

Later

RE: Pinion angle
 

I don't see a point. The aluminum one is actually about half a pound lighter than the CF.

The advantages of the CF are relatively minor. It does reduce vibration slightly, and if you break it, it is less likely to damage your car's floorpan. But I don't think that is worth the high cost!

RE: Pinion angle
 

if the pinion angle is the same as the tranny angle then you net angle is "0". With polyu bushings you want between -1 and -3. I have a one piece al. driveshaft......the driveshaft is at 5 degrees and the pinion flange is at 2.5 degrees. PINION ANGLE MINUS DRIVESHAFT ANGLE EQUALS NET PINION ANGLE (i.e. 2.5 - 5 = - 2.5). thats how I set mine.....if you have a different opinion, Im willing to listen.

RE: Pinion angle
 

You used the technique for the 2-pc OEM shaft.

With a typical driveshaft you want the two angles (transmission-to-driveshaft and driveshaft-to-pinion) to be equal. Why? Because a universal joint does not transfer power linerarly (smoothly) as they rotate. They produce a wavy torque output that looks like a sine wave. But, driveshafts have two of them (one on each end), and they are located 180-degrees out of phase from each other. That means that they cancel out each other's "waviness", but only if the angles are equal.

You want these two angles to be the same. The easiest way to do this is to make the flanges paralell.

Here is some reading you can do:

http://www.carcraft.com/howto/91758/

This one is a Jeep site, but it explains the difference between CVs (OEM style) and Universal joints (1-pc / traditional style) very well, and it talks about the "wavy" torque transfer that I talked about:

http://www.4x4wire.com/tech/pinionangle/

RE: Pinion angle
 

Thanks for the links CrazyAl.

RE: Pinion angle
 

This is the resource I used.....I dont believe they are using a 2 piece driveshaft for an example.........

wolfcraft

RE: Pinion angle
 

I have read that article but I don't agree with it. The problem with this technique is that they are making a lot of assumptions that are not always true.

We have already established that for proper operation of a driveshaft with U-joints, the two angles (transmission-driveshaft and driveshaft-pinion) need to be equal.

However that article doesn't even mention the transmission-driveshaft angle. How can you properly set the pinion angle (driveshaft-pinion) if you don't know the trans-driveshaft angle? You can't.

That article is making a "shortcut" assumption that the angle between the transmission and driveshaft is at some specific number. (probably about 3 degrees seeing as that is the number they are trying to push on you). The trouble is, what car are they talking about? Has the car been lowered? Is it raked? Are there any other suspension mods on it? We don't know. And all of these things can affect what the proper angle should be.

A pinion angle of 3 degrees might be ok for an old Chevy Nova with 30" slicks in the back. Does that mean it is OK for a late-model mustang with street tires? Maybe. Probably not. What about my jacked-up rock crawler with 40" boggers on it? Heck no.

The measurement on your car might not be correct for my car even though they are both late-model mustangs. You and I have different suspension setups, so you can't apply my measurement to yours or yours to mine.

The only way to do the job right is to take the transmission side measurement on YOUR CAR, that way you are not making any assumptions and you can set things up correctly for YOUR CAR.

Lift up the car and support it level, with the suspension loaded, just like it would be if it was sitting on the ground. Remove the driveshaft from the car. Use your gravity-type angle gage to measure the angle of the transmission output flange. Then set the pinion flange to that same angle.

By the way, some people belive you should add a little negative angle to the pinion (nose-down), so that under race conditions if your bushings flex, then an equal-angle situation will result. However, if you have aftermarket rear-end suspension parts with poly bushings or heim joints, you are not going to see any significant deflection, so this point is moot. If you're adjusting your pinion angle then you already have aftermarket control arms with the poly bushings in them.

RE: Pinion angle
 

man crazy i wish you lived by me i cant find anyone that can do this and i know i cant figure it out [:@]