I have a '66 C60 (single rear axle) with a 3-piece driveshaft that I need to phase. I neglected to mark the u-joints before disassembly and now need to know the proper phase. I looked at one other truck and it seems to have the front and rear shafts clocked parallel and the center shaft 90° out of phase. Talked to a mechanic that used to work for a Chevy dealer back about 1980 and he thought one shaft should be out of phase but couldn't remember the exact setup.
Anyone have GM manuals that tell the proper setup?
Unless you removed the slip joints and changed their positions, it won't matter a lot how you put it back together, assuming the assembly was balanced. If you can identify the three sections and put them back in the same locations, it should be OK. Yes, the u-joints can be assembled rotated 180 degrees from their original positions, but that's not what phasing is. Phasing is the angles between the u-joint yokes on the same section of driveshaft. Typically an in phase section would have the axis of the yokes in the same plane and as I mentioned, the only way to change that is by installing the slip joint incorrectly on a section. Many times that's impossible because of a spline that's keyed to only go together one way.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Unless you removed the slip joints and changed their positions, it won't matter a lot how you put it back together, assuming the assembly was balanced. If you can identify the three sections and put them back in the same locations, it should be OK. Yes, the u-joints can be assembled rotated 180 degrees from their original positions, but that's not what phasing is. Phasing is the angles between the u-joint yokes on the same section of driveshaft. Typically an in phase section would have the axis of the yokes in the same plane and as I mentioned, the only way to change that is by installing the slip joint incorrectly on a section. Many times that's impossible because of a spline that's keyed to only go together one way.
The slip joint in this setup is the problem. I failed to mark it when I took it apart and it isn't keyed so it can be put together in any position.
I think on most driveshaft sections, the u-joint axis should be parallel on each end. Hopefully someone can help you out with a picture or a confirmation of that. Which section is the problem?
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
I think on most driveshaft sections, the u-joint axis should be parallel on each end. Hopefully someone can help you out with a picture or a confirmation of that. Which section is the problem?
The center section is the problem because of the spline slip joint. I just assumed it would be phased parallel when I took it apart and didn't look.
Perhaps these two diagrams may be of some help in your drive shaft section alignment.
The 1st pic is from a 1966 Chevrolet Truck Illustration and Special Information Catalog, showing the common 2 and 2-1/2 ton propeller shaft layout. You should be able to zoom in to see the orientation of the yokes from transmission output to rear axle, section by section.
The 2nd pic is another diagram from a 1968 Chevy C10-60 Shop manual showing the propeller shaft sections and yoke orientations. I checked and it's actual the same diagram going back to a 1963 Shop Manual, so should apply to your '66.
Maybe enough to help you get the segments all back together and lined up as they should be?
Let us know how it turns out.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Thankyou very much for looking up the diagrams. It appears my 3-piece should have the yolks lined up parallel on each section. ° The only one shown to have a shaft clocked 90° out is on the 2-piece setup. That was probably what the mechanic I talked to was thinking of.
With the rear tires off the ground and brake applied, rotate the drive line till the front u-joint is setting straight up and down and side to side.
Set the the transmission yoke vertical, the driveline yoke will be horizontal,
The second u-joint inline will have the front driveline yoke horizontal, and the second drive shaft yoke vertical.
The third u-joint will still have the second drive line yoke vertical, and the slip yoke horizontal.
The forth u-joint will have the last driveline section yoke horizontal, and rear pinion will be vertical.
If you lay each section of drive line on a level surface, the yokes will be inline with each other.
The picture below shows how each section should be, the RED portion is a Yoke, Blue section driveline. The slip joint still counts as part of a driveline and needs to match the picture. Use a straight edge to verify the yokes are parallel on the slip joint.Type 1 PARALLEL – PARALLEL
