Good afternoon or whatever it is in your part of the world. As the title states I'm looking for some driveline angle help.
First some background. I acquired my car back in February of this year and since then have been driving it on the street and assessing it's needs to make it a part time track car. I'm looking to start slowly as I have zero experience in any road course racing but have been wrenching fast cars (and slow ones) since I was a kid. I'm 59.
So that's my background, now the car.
It's a 2014 track package, GT premium, it has 21K miles on it, it's very clean and doesn't appear to have been abused. All of the track package suspension items have been replaced with decent aftermarket products. The car has a Steeda adjustable UCA as well as the other items that you can see in the first picture. The work I did right away was the typical fluid changes and a right rear outer bearing and seal. No idea why that went but there was a significant amount of play in it with no obvious sign of taken a any sort of lateral impact. I also had an alignment done using specs I found on this site from those using their S197s on the track. I asked them to check the pinion angle as well.
Now to the real problem with the car. Since day one I've been chasing a "whine" that starts around 60 mph, gets max volume in the car at about 70 and then stops at 80. It doesn't change with what gear I'm in, if it's in neutral or my foot's on the clutch. It's purely speed dependent. Since replacing the axle bearing didn't touch the problem, I figured the 2 piece driveshaft was the most obvious culprit. I was hoping it wasn't the diff. Obviously the gear lube was changed when I did the bearing and seal and the noise was still there. Upon visual inspection of the the carrier bearing I didn't see any degradation of the rubber collar but the bearing had, what seemed like, significant movement. Given the age of the car, despite the low miles, plus the added benefits of a one piece, I went ahead and ditched the stock shaft this weekend and put in an aluminum 1 piece from Steeda. My heart sank during the test drive when the noise was the same as before the driveshaft swap.
I want to share my readings that I got from measuring my pinion angles to see if that may be where my problem lies. I included pictures but basically I've got the front wheels on cribbing and the rear axle supported with jack stands. The car is as level as I can get it. I've taken the pitch of the floor into consideration and took measurements from the rim of the wheel to the ground front and back as well as a reading at the pinch weld.
After that I took a reading at the vertical cover on the front of the bell housing as well as the output shaft and read zero or very close. This was a surprise to me, I expected to see some downward angle to the engine/trans. The reading at the flat spot on the bottom of the diff housing was 2.4 degrees up(?). The driveshaft also showed 2.5 up.
I thought I'd see downward angles. Visually, it appears it's sloping down from front to back so maybe it was because the gauge is upside down. I included pictures of those too.
So what do you all think of these numbers? Steeda recommends -1 to -2.5, am I at -2.5 since the engine is zero?
Any help or advice is welcome, thanks in advance!
Marc
First some background. I acquired my car back in February of this year and since then have been driving it on the street and assessing it's needs to make it a part time track car. I'm looking to start slowly as I have zero experience in any road course racing but have been wrenching fast cars (and slow ones) since I was a kid. I'm 59.
So that's my background, now the car.
It's a 2014 track package, GT premium, it has 21K miles on it, it's very clean and doesn't appear to have been abused. All of the track package suspension items have been replaced with decent aftermarket products. The car has a Steeda adjustable UCA as well as the other items that you can see in the first picture. The work I did right away was the typical fluid changes and a right rear outer bearing and seal. No idea why that went but there was a significant amount of play in it with no obvious sign of taken a any sort of lateral impact. I also had an alignment done using specs I found on this site from those using their S197s on the track. I asked them to check the pinion angle as well.
Now to the real problem with the car. Since day one I've been chasing a "whine" that starts around 60 mph, gets max volume in the car at about 70 and then stops at 80. It doesn't change with what gear I'm in, if it's in neutral or my foot's on the clutch. It's purely speed dependent. Since replacing the axle bearing didn't touch the problem, I figured the 2 piece driveshaft was the most obvious culprit. I was hoping it wasn't the diff. Obviously the gear lube was changed when I did the bearing and seal and the noise was still there. Upon visual inspection of the the carrier bearing I didn't see any degradation of the rubber collar but the bearing had, what seemed like, significant movement. Given the age of the car, despite the low miles, plus the added benefits of a one piece, I went ahead and ditched the stock shaft this weekend and put in an aluminum 1 piece from Steeda. My heart sank during the test drive when the noise was the same as before the driveshaft swap.
I want to share my readings that I got from measuring my pinion angles to see if that may be where my problem lies. I included pictures but basically I've got the front wheels on cribbing and the rear axle supported with jack stands. The car is as level as I can get it. I've taken the pitch of the floor into consideration and took measurements from the rim of the wheel to the ground front and back as well as a reading at the pinch weld.
After that I took a reading at the vertical cover on the front of the bell housing as well as the output shaft and read zero or very close. This was a surprise to me, I expected to see some downward angle to the engine/trans. The reading at the flat spot on the bottom of the diff housing was 2.4 degrees up(?). The driveshaft also showed 2.5 up.
I thought I'd see downward angles. Visually, it appears it's sloping down from front to back so maybe it was because the gauge is upside down. I included pictures of those too.
So what do you all think of these numbers? Steeda recommends -1 to -2.5, am I at -2.5 since the engine is zero?
Any help or advice is welcome, thanks in advance!
Marc
