CV Driveshaft

[andrewb70]

Today I got a couple of beautiful driveline parts from The DriveShaft Shop. These will be going in a 1967 Cougar.

Goodbye 100 years old u-joint technology and welcome to the 21st century...



First is this 27 spline slip yoke for my T56 transmission:



I do believe that a 32 spline version is also available that will work with TH400, etc...

It is set up to use one of their 100mm CV joints.



This beauty is a pinion flange for the 9" rear end. There are versions for the 12 bolt also available.



It is machined to accept one of their 108 mm CV joints.



Once I get everything installed I will measure for an aluminum driveshaft (with CV joints t both ends) to go in the middle. Concerns about driveline angles will be a thing of the past. The front and rear operating angles don't have to be equal and opposite anymore, as long as the operating angles don't exceed 9 degrees.

Andrew

[carbuff]

Those are nice, and they have that "cubic dollar" look to them. ;)

As someone who has a little bit of driveline vibe in my car, this might be a nice option for me too at some point...

[andrewb70]

Those are nice, and they have that "cubic dollar" look to them. ;)

As someone who has a little bit of driveline vibe in my car, this might be a nice option for me too at some point...

The yokes are actually priced in line (even less than some) with other billet yokes on the market.

Andrew

[TheJDMan]

Andrew,
Is the double CV shaft a lot more expensive than the carbon fiber one you had pictured earlier? I was also wondering if you could tell a difference in drivability with the carbon fiber shaft. Specifically I'm wondering if the cf shaft twists to absorb shock loads. I have heard comments to the effect that a cf shaft just runs smoother and quieter in general than a steel or aluminum tube type.

[andrewb70]

Andrew,
Is the double CV shaft a lot more expensive than the carbon fiber one you had pictured earlier? I was also wondering if you could tell a difference in drivability with the carbon fiber shaft. Specifically I'm wondering if the cf shaft twists to absorb shock loads. I have heard comments to the effect that a cf shaft just runs smoother and quieter in general than a steel or aluminum tube type.

The double CV shaft will cost more, but how much depends on what you do. For instance, when I installed mine, I also installed a Mark Williams billet yoke in my 12 bolt. That yoke was stupid money and is actually more expensive than the CV pinion yoke. So really, if you are going to swap pinion yoke anyway, the cost difference is only the addition of the second CV joint. The plan for the Cougar is to swap the pinion yoke and use an aluminum shaft with CV joints at both ends.

As for the carbon shaft, I don't really know that it made a lot of difference in quieting the driveline noise. I used to have a pretty noisy R&P whine, I had the R&P replaced, and the whine is less, but not completely gone. It's annoying. I hate all manner of unintended gear noise.

Hope that helps.

Andrew

[Nothingface5384]

How would a c/f shaft work since the yokes are billet AL?

[andrewb70]

How would a c/f shaft work since the yokes are billet AL?

You have to be more specific as to what yokes you are talking about. The transmission slip yoke and the pinion yoke are billet steel. To them bolts the CV joint that has a steel splined shaft that is bolted to an aluminum driveshaft yoke. The CF tube is bonded to that aluminum yoke. The sequence is repeated on the other side in reverse order.

This is what it looks like on the transmission side:



Andrew

[TheJDMan]

Andrew,
Those CV joint adapters, on the transmission adapter you said is for a 100mm joint and the 9" adapter is for a 108mm CV joint? Why use different sizes of CV joints?

[andrewb70]

Andrew,
Those CV joint adapters, on the transmission adapter you said is for a 100mm joint and the 9" adapter is for a 108mm CV joint? Why use different sizes of CV joints?

My guess is that it has to do with the spline count on the transmission. The T56 uses a rather small 27 spline output shaft. My Richmond 6 spd has the big GM 32 spline output and has the bigger CV. It's not unlike having different size u-joints for different application. Obviously a 9" rear can handle ample power, thus the bigger CV size.

Andrew

[CTX-SLPR]

Watching this since I have factory CV's at both ends of the rear section of my Riviera's 2 piece shaft and they are a pain to get serviced and like you point out, very old technology.

[andrewb70]

Watching this since I have factory CV's at both ends of the rear section of my Riviera's 2 piece shaft and they are a pain to get serviced and like you point out, very old technology.

Does your Buick use the old style double-cardan CV joints?

Andrew

[CTX-SLPR]

Does your Buick use the old style double-cardan CV joints?

Andrew

Yup... One just behind the carrier bearing on the slip section and another on the bolt on pinion flange. Going to have to replace/modify the rear section anyway for the planned swap to an 8.5/8.625in 10-bolt for more options.

[andrewb70]

Yup... One just behind the carrier bearing on the slip section and another on the bolt on pinion flange. Going to have to replace/modify the rear section anyway for the planned swap to an 8.5/8.625in 10-bolt for more options.

I'd love to see pictures of that set-up!

Andrew

[CTX-SLPR]

I'll see what I can find from when I've had it apart. With the X-frame the middle of the shaft is tucked up out of view.

Right now the rear CV is not in good shape but I ran out of time before my most recent move to get it fixed.

[andrewb70]

I'll see what I can find from when I've had it apart. With the X-frame the middle of the shaft is tucked up out of view.

Right now the rear CV is not in good shape but I ran out of time before my most recent move to get it fixed.

No worries. I Googled around a bit and have a pretty good idea of what you have. It's interesting that the luxury brands of the time (Buick Riv, Caddy, etc...) all had two piece driveshafts with the double cardan CV joints. I am sure that was done for smoothness.

Look at moder muscle cars. A 2011 Mustang has a 107 in wheel bases but uses a 2-piece driveshaft with dual CVs in the rear section. This is no accident. Modern IRS cars can get away with u-joints, but still use 2-piece driveshafts and rubber guibos to isolate driveline noise.

Andrew

[andrewb70]

I was looking at some build pictures of the Ken Block 1965 Mustang and this picture caught my eye. See anything familiar?



Andrew

[TheJDMan]

Update, I have been chasing a drive line vibration for the past three years. First I found a thrust washer missing in a cap of the original rear Spicer U-joint that was installed in my custom drive shaft. As I mentioned in a previous post in this thread, I installed a NAPA U-joint to replace the original to get the car back on the road and later ordered a pair of Spicers to keep as spares. Well I never suspected that the replacement U-joint might also be bad. In any case, today I removed the drive shaft to work on fabricating a DS loop and was stunned to discover that the rear joint I had installed last year was seized up. So I installed one of the spare Spicer joints I had and put everything back together. I still need to get it out on I95 for a sustained high speed run to make sure but it seems my remaining vibration is gone now. So for the past three years total I have been chasing a vibration which was first one U-joint improperly installed and then just my luck a second bad joint. Go figure.

[raustinss]

Cough cough ...this is where a cv joint d.s comes into my mind lol

[carbuff]

Back in February, I called The DriveShaft Shop and spoke with Frank about a CV carbon shaft for TOW. He actually talked me out of the CV joint saying it shouldn't be necessary. He told me that replacing the trans mount with a rubber mount and using a CF shaft should be enough, but offered to upgrade the shaft to a CV if I needed it. I just installed the new shaft the other night, but the car is down for other work, so I haven't been able to test it yet, but I still in the next month or so...

[TheJDMan]

Frank at the DriveShaft Shop told me the same thing about the rubber transmission mount and CV joints.