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Mix & Match Drive Shaft for 1963 Riviera upgrade to ST400?


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I have a complete 1964 Driveshaft with the differential Pinion Flange. It is a worn-out core requiring complete rebuild.


Maybe a silly question, instead of having the entire assembly rebuilt and disturbing the pinion bearing spacer crush. Can I insert the front half of the '64 drive shaft into the '63 rear?


I know, even if physically possible, mix & matching may be opening a can of worms. However, it may not hurt to keep the assembly simple. Not sure why the '64 switched to those CV Joints when the '63 didn't have them.

I would also switch the front slip yoke to a standard version and install a later version of the ST400 tailshaft housing to accept it. A "Franken-Shaft".




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There is NO crush collar on the 9 3/8ths. ring gear. Just spacers so torque newer yoke. replace pinion seal while your at it. 

I have them in stock.

The '64 shaft is a better design so keep it as is, complete.

Make sure the person rebuilding the shaft is knowledgeable about them. Bring in the chassis manual for them to read thoroughly. Follow directions & mark EVERYTHING as it comes apart.

Make sure the pinion angle is correct.

Good choice on upgrading the rear housing to the newer style. Now you can get a NEW slip yoke for the trans. Don't forget to get a new rear seal & bushing IF nec.


Tom T.

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1 hour ago, telriv said:

The '64 shaft is a better design so keep it as is, complete.

Again, thanks for your advise Tom.

Obviously a reason why Buick changed the Drive Shaft design. Probably to go with the new ST-400 that only "High-End GMs" received for 1964. Entry level Cadillacs had to make do with 1963 carry overs.


Hopefully I didn't mess up the Pinion Flange. I thought the threads were rusted out. 3/8" bolts fit sloppy and 7/16" bolts went in a half turn. All the time assuming 3/8th. So in my wisdom, drilled out all 4 holes and tapped for 7/16th. The tap basically chased the original threads where the drill did not eliminate them. They were 7/16" all along! All 4 bolts now screw in with my fingers. Too loose?

I should've checked the shop manual before proceeding.😛


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Interested in how this comes out.  


I have thoughts of doing a frankenshaft from the opposite direction.  63 front and 64/65 rear section.  I have all the bits here to do it, but haven't gotten past thinking on it.   Apparently the 63 shafts were prone to vibration, which would explain why they changed things early in the 64 run.   Its interesting that the 63 is 105 degrees out of phase and the 64/65 is 67 1/2.  Not sure if the back section from the later shaft can be inserted into the 63 to achieve either result or which would be prefereable.  


If I was swapping to a 400, I would use a complete 64/65 shaft with the lower center bearing.   Only issue I see there is the bolt spacing on the center bearing mount is wider on the later set up.  Not sure how to re drill the frame and make sure its properly centered.   As Tom said above, changing the pinion flange is no big deal.  


If I recall correctly, Tom T mentioned in another thread some time ago that the two sections were balanced separately.   Later guidance is to have a truck shop balance the whole rig.    


Some day when i get bored, I might play mix and match to see what happens.   



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Phasing on the 63 driveshaft is 101* not 105*.

I have swapped a 4L60E transmission into my 63 Riviera using the original drive shaft. All u-joints were replaced with Spicer brand. I had problems with poor materials  and tolerances used in the Moog brand. The front stub shaft had to be shortened so I took it to a local commercial truck service center and made sure they knew of the 101* phasing. These businesses work on driveshafts regularly and understand why things are done a certain way.  The driveshaft was shortened and balanced with no problems.

As Buick in the day used a specific tool for alignment of the driveshaft and only a few lucky souls have access to that tool, I did some research on driveshaft alignment and  by using this publication that explains why the alignment angles are used, was able to get mine done without vibration. The only extra tool needed to do this is a digital angle gauge.

Wixey Digital Angle Gauge Type 2 with Magnetic Base and Backlight


Spicer drivetrain publication:



The illustration that I used for alignment is attached.


Before you remove the driveshaft I would suggest taking measurements of the angles as originally installed. You would need to know the angle for the engine, front shaft, rear shaft and pinion flange. I did this with the car sitting level on 4 tire ramps. I zeroed the gauge off of the frame were the center bearing is mounted. The engine angle was taken on the flat area by the starter, the angle of the shafts directly on the tubes. Make sure you have the gauge perpendicular to the floor, if not it will read a different angle. You will need to release the driveshaft from the pinion flange and the flanges u-joint mount point also needs to be perpendicular to the floor so you will have to jack the differential up to do that. I used a deep socket that fit the diameter of the u-joint mount point to give me a flat and accurate mount spot for the gauge. Also perpendicular for the gauge there. 

The front shaft angle is to make sure you have some angle greater than zero and less than 3*. Mine was 1.5* and is probably not what you will have as I have a different transmission with different mounting height for the rear transmission mount. The shims at the center bearing will let you change that angle. The rear shaft angle and the pinion flange angle  are what need to be the same. The gauge will give you a reading that is 90* different that the shafts, you will have to add or subtract making sure you know whether the gauge is reading up or down. The gauge will show an arrow. Mine matched was without adjustment to the top mount arm. 

This took some time to do but can be done without a helper. The math of driveshaft alignment hasn’t changed so what the guys didn’t have back in the day was the digital gauge and that is what makes doing this today without the “tool” viable.

If you do use this please post your original angle readings as I didn’t have that when I did this. I had the engine out before I decided to do this.


I also have a spare 64/65 driveshaft with pinion flange in case I need it but with rebuild parts for the cv joint impossible to source, I think  the original driveshaft should be looked at as a viable solution first. 



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3 hours ago, Zimm63 said:

 Its interesting that the 63 is 105 degrees out of phase and the 64/65 is 67 1/2.

Reason to take Tom's advise and stick with a complete assembly. Although, I've encountered a few posts on this Forum all dealing with Driveshaft vibration on 1964 - 65s.

3 hours ago, Zimm63 said:

Only issue I see there is the bolt spacing on the center bearing mount is wider on the later set up.

Too bad the center support wasn't in reverse. Could always shim it up to the correct height/angle. Power Train Industries no longer list their P/N: 3R80-25 Support for the '63, re-vulcanize original at Steele Rubber.

4 hours ago, Zimm63 said:

the two sections were balanced separately.

Only way to balance them is dynamically. So yes, balanced individually. My core assembly has a huge swack of balance weights spot welded on!

If after balancing, there's vibration and if there's no master spline, the two shafts can be re-indexed 180° from original in trouble shooting. Looking at the drawings, the center spline appears the same for 1963 & 1964.

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16 minutes ago, BulldogDriver said:

64/65 driveshaft with pinion flange in case I need it but with rebuild parts for the cv joint impossible to source

Great Info, thanks Ray! Thanks for the Link, awesome.

You sticking with your 1963 driveshaft for a non original transmission swap worked out well I see. Which leads back to my thinking of using only the front half of my core 1964 Assembly and keeping the aft shaft of the '63 since my swap will be original for 1st Gen being a TH-400 and especially if all parts can't be sourced for the '64. 

It wouldn't hurt to try just the front half 1st, baby steps. Only I wonder if it's physically possible with splines at the center bearing?



Images below are parts in the trunk of a '65 Riv at a car show where the Owner was preparing to address his vibrating driveshaft. Have yet to hear of a vibrating 1963 Riviera Driveshaft!







Edited by XframeFX (see edit history)
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Ed I believe it would differ between transmissions and the rear mounts. I modified my original rear mount and had to move it back 3” which in itself was not a hard thing to do. The holes for mounting were 3” on center and tack welding a bar to 2 3/8” nuts at 3” on center you can fit it up into the frame without any modifications. I made a template to drill the hole to move the mount back by using the original 2 holes to keep the mount on the same plane as it was originally. The mount had to be heavy modified to clear the transmission pan and relocate the transmission mount. Also strengthen the the mount with c-channel. Probably overkill but I won’t need to worry about it. This is not the finale product but it gives you an idea as to what had to be done to make it work.






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I reread my post and what I should have said was from the tail shaft housing on the transmission to the carrier bearing.  If that distance changes, the angle would change.  The angle between the carrier bearing and the rear end would stay the same.  

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1 hour ago, RivNut said:

I should have said was from the tail shaft housing on the transmission to the carrier bearing.

Would this not be the reason why the center support is lower on the '64 than the obsolete '63 support? (screen-shot).


Ray modified his Dynaflow Trans Mount. However, using a '64 ST-400 mount in a '63 frame, I'd have to drill holes exactly as on the '64 or, after figuring out angles, drill where required.


Angles can be figured out later. Still need to determine if center support splines are the same between the 63 & 64. And now, as it appears with dialogue here, will need to swap the taller '63 center support to the '64 and modify to mount with the 2 bolts being different.


Of course, I should go for Quotes on rebuilding my '64 driveshaft assembly if CV joint parts are available. I have no idea the cost. If no sticker shock, proceed.


My plan is to use 1st Gen parts in my 63. If mix & matching driveshaft components doesn't work, I can continue to invest in a rebuilt aft section of the '64 driveshaft assembly. Nothing is irreversible here except for drilling holes in the frame and possibly the tunnel.

There have been 1963 Riviera's fitted with ST-400s. I'll be the next to swap and possibly not the last.


Thank-You All!



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