DWC's 1968 Camaro project

[Barnburner]

One of the best things about this forum is the lack of criticism for honest mistakes. You can post your victories and everyone supports you, if you step on your hoo-hoo and everyone still supports you!

[WSSix]

That's because we try to make it more of a community instead of a hive mind one up fest like so many other forums turn into. We all have our visions and we'll all need help getting there. It's why I came here from other places. Those other places certainly have valuable information available, too, but this place feels better.

Good work on the car, DWC. I feel your pain with the vibrations. I still have not figured mine out. I swear I have the angles dialed in, but I need to check again with a drive on lift preferably. Keep at it with a methodical approach and you'll get it. Don't forget to keep the working angle of each joint below 3*, as well. I completely missed that in my efforts to make my angles equal and opposite.

[DWC]

I've been putting some miles on the car. Not as many as I'd like though.

My son and I went to the local Cars and Coffee the other week, which is always fun. (I robbed some photos off the C&C Facebook page)

I still have a driveline vibration that's bugging me. The front and rear driveline operating angles are both exactly 2.9* and the overall operating angle is .02*. Even after I was able to get these angles, I still have a vibration at around 2000 rpms, then it goes away until about 4500 rpms. Above 4500 rpms, it's a fairly significant vibration. The engine revs smooth though, in neutral, to the limiter so I'm confident it's not the source.

I took my driveshaft and had the balance checked yesterday- all good. It has new Spicer U-joints. I have sufficient yoke engagement on the trans output shaft. I spoke with Ridetech this morning to see if they had any suggestions and he said with my pinion angles and a good driveshaft, he wasn't sure of where to go next.

Someone mentioned driveline compound angles, which is one thing I haven't checked. The Tremec app measures the angles on a horizontal plane, but I haven't checked them on a vertical plane. At a glance, it "looks" pretty straight. Anyone have any tips on checking compound driveline angles?

Also, I've grabbed the driveshaft right in front of the rear pinion and tried to shake it and there's very little/if any play. I was told when I bought it that the pinion and axle bearings had been replaced. But, I have noticed a very slight pinion seal leak because the bottom of the length of the rear end pumpkin is slightly damp with fluid.

Any ideas would be greatly appreciated.

Daniel

[ScotI]

Originally Posted by DWC

I've been putting some miles on the car. Not as many as I'd like though.

My son and I went to the local Cars and Coffee the other week, which is always fun. (I robbed some photos off the C&C Facebook page)

I still have a driveline vibration that's bugging me. The front and rear driveline operating angles are both exactly 2.9* and the overall operating angle is .02*. Even after I was able to get these angles, I still have a vibration at around 2000 rpms, then it goes away until about 4500 rpms. Above 4500 rpms, it's a fairly significant vibration. The engine revs smooth though, in neutral, to the limiter so I'm confident it's not the source.

I took my driveshaft and had the balance checked yesterday- all good. It has new Spicer U-joints. I have sufficient yoke engagement on the trans output shaft. I spoke with Ridetech this morning to see if they had any suggestions and he said with my pinion angles and a good driveshaft, he wasn't sure of where to go next.

Above, Jack mentioned driveline compound angles, which is one thing I haven't checked. The Tremec app measures the angles on a horizontal plane, but I haven't checked them on a vertical plane. At a glance, it "looks" pretty straight. Anyone have any tips on checking compound driveline angles?

Also, I've grabbed the driveshaft right in front of the rear pinion and tried to shake it and there's very little/if any play. I was told when I bought it that the pinion and axle bearings had been replaced. But, I have noticed a very slight pinion seal leak because the bottom of the length of the rear end pumpkin is slightly damp with fluid.

Any ideas would be greatly appreciated.

Daniel

The driveline angle thing gets compounded when the cars get lowered. Standard driveline angles are calc'd & figured w/everything 'sloping' front to rear (motor higher than trans output; trans output higher the rear pinion). The closer these get or in the extreme cases where the pinion is higher than the trans output, a diff approach is required.

I know this from the custom truck scene. Extreme lowered trucks are faced w/this scenario constantly. Many (most?) ignore it or don't drive them enough to be concerned. My plan on my trucks was to use a single driveshaft vs the more common 2pc shafts; dial in angles as good as possible, & then if that didn't work swap in a double cardan style u-joint/CV joint that cancels vibrations within itself. By using the Dbl cardan style joint, you need to dial in the angles close to zero & let the joint do the work.

Check out Andrewb70's stuff. I don't recall where I saw/read the info but I believe when he did the 'rebuild' of his GTO (the L92 swap period) he really focused on solving the vibration issue. He wound up sourcing a driveshaft/joint combo that while expensive.... got the job done. Since I had already been researching options, his info was REALLY good to read as he was using the same approach I have as far as the whole process of elimination.

Hope this info helps.

[WSSix]

Yep, Andrew put a CV joint on the front of the driveshaft. I believe he got it from Driveshaft Shop. I was thinking I needed to go that way as well since my diff is inline if not above my transmission. I'm in the middle of checking something else right now before I go down the path to using one of those driveshafts.

I can't help with your issues. I know it's frustrating as hell. I wish you the best in figuring it out. The car looks great.

[Spiffav8]

Daniel the car looks wicked!! Stoked to see you out driving it and having some fun. The shake down process just just part of the journey.

[DWC]

Thanks guys.

This weekend I'm going to take some measurements. I plan to measure runout on the driveshaft, rear axles, and pinion. I'll also try and check the rear end position/alignment if I can figure out a proper way to do it.

Daniel