C1 '58 4sp. transmission slip yolk

[terry leeker]

With the car at body height specs and original driveshaft (34" CTC, still had the remains of the stencil when I cleaned it) and rear springs, I have about 2.25 inches of yolk shaft exposed. This seems excessive compared to my experience with other similar vintage vehicles. Most are about 1 to 1 1/2 inch. Springs can only go on one way and if I had the wrong spring hangers (55-56?), I would have the opposite problem. I have added pinion angle spring shims to get to 2 1/2 Deg, diff. yolk up. What am I missing.

[John H.]

Re: C1 '58 4sp. transmission slip yolk

There's a lot of fore-aft movement of the yoke with rear suspension travel, which is why the Corvette used a 4-1/2"-long yoke (about 1-1/2" longer than the yoke used on passenger cars); if you have the original prop shaft and yoke, you shouldn't have a problem. The C1 U-joint angles were also extreme, and the operating angles should be the same at both ends, with parallel axes; the stock pinion angle is down from horizontal, not up, so it matches the operating angle of the front U-joint (see p. 42 in Noland's book). A mismatch between front and rear U-joint operating angles will result in a driveline vibration.

[John H.]

Re: C1 '58 4sp. transmission slip yolk

There's a lot of fore-aft movement of the yoke with rear suspension travel, which is why the Corvette used a 4-1/2"-long yoke (about 1-1/2" longer than the yoke used on passenger cars); if you have the original prop shaft and yoke, you shouldn't have a problem. The C1 U-joint angles were also extreme, and the operating angles should be the same at both ends, with parallel axes; the stock pinion angle is down from horizontal, not up, so it matches the operating angle of the front U-joint (see p. 42 in Noland's book). A mismatch between front and rear U-joint operating angles will result in a driveline vibration.

[terry leeker]

Re: C1 '58 4sp. transmission slip yolk

Thanks John, I feel better about the yolk situation and you are correct in discribing the Diff./Trans/u-joints relationship. I have it as you discribed.

[terry leeker]

Re: C1 '58 4sp. transmission slip yolk

Thanks John, I feel better about the yolk situation and you are correct in discribing the Diff./Trans/u-joints relationship. I have it as you discribed.

[Roy B.]

Re: C1 '58 4sp. transmission slip yolk

No the rear springs can be installed wrong, I've seen many C1's where the owner had the rear spring UNDER the rear frame and not OVER the rear frame. Which will raise the rear body line. Looks cool but not correct and will work OK.

[Roy B.]

Re: C1 '58 4sp. transmission slip yolk

No the rear springs can be installed wrong, I've seen many C1's where the owner had the rear spring UNDER the rear frame and not OVER the rear frame. Which will raise the rear body line. Looks cool but not correct and will work OK.