Howdy! I have my '72 Riv off of its frame. I finished repairing the frame rust, painted the frame inside and out, installed new fuel and brake lines, new adjustable trailing arms, etc. My built 4L80E is going to be ready in a week or so. I had a question about the pinion angle. I am used to setting it on shafts that just have one U-joint at each end. This big Riv has a single joint at the slip yoke and a double cardan at the rear. The '71 shop manual I have from Buick says 0.25 degrees of angle at the front and 10 degrees of angle at the back. Does that sound right? I think I am mostly asking because sometimes factory angles were not ideal for various reasons (e.g. clearance). Any tips related to this setup would be appreciated. Also is it mandatory to have the body on the frame when I do it? Can I just remove the rear springs and level the frame? Bonus question: when installing brake/fuel lines with gravel guard springs around them, do you run the spring continuous under the hold-down clamps or do you cut the springs into sections so the clamp is only holding the tubes? I went with cutting it into sections but I see +/- to both methods so I'm second guessing myself. Thank you!!! Joe
FWIW, I measured the new trailing arms to make sure they are adjusted to the exact length of the stock arms. With the rear springs removed and the frame leveled, the trans tailshaft is pointed about 0.5 degree down at the ground and the pinion is pointed 11 degrees also down at the ground... If it were a single cardan driveshaft these angles would be terrible. I don't know much about double cardan geometry but having the hog's head looking 11 degrees down at the floor seems very wrong.
OK, probably have no idea what I am talking about. The only angle that will change is at the rear u joint. The pinion will roll up from engine torque. You want 0 angle under full load. From the 72 Buick Chassis Manual, Doesn't say + or -. Maybe your angles are OK.
Larry, that is what I am thinking. Maybe my angles are right and just seem wrong since I am not used to the double cardan. Lucas, thanks for the diagram! My Riv is actually reversed with the double cardan at the hog's head but similar principles should apply. It is odd though because I set it up with the stock geometry, which I feel is further confirmed by the coil spring perches being level, and the hog is looking at the floor. If I adjust it to look upwards then the perches will be in the wrong spot. Not a problem to re-weld them but if I'm going for stock geometry I shouldn't be required to...
