Technical Yoke Clearance

This is on my 1955 Chevy car. Turbo 350, leaf and stock rearend. I only have about 1/2 inch of movement available. Too little? I know ideal is 3/4 to 1”.
Thanks

 

If that is at ride height, it is not enough.

Sorry. -Abone.

 

Is that at ride height? On ground or jacked up,under rear? You want three quarters to an inch

 

Ride height

 

It has jack stands under the rear axle. Any chance the new u-joint will survive being pushed out of this driveshaft? Looks like I need a 55.5” driveshaft

 

I would bounce it at ride height and see if the distance gets bigger or smaller. If the space gets bigger it should be OK.

 

Bounce the hell out of it and see if it hits. Closer to an inch is better by all means, but I've ran them like yours with no issues.

 

I just went thru this same question after a pinion angle change/replacement rear end in my Willys drag car.
Short version, I changed the pinion angle (removed 3*), which in turn moved the pinion yoke UPWARDS, making a SHORTER distance between the trans output shaft/yoke and the differential yoke. The driveshaft (high zoot/big dollar piece), pushed the trans output yoke to within 5/8" of the back of the transmission output shaft housing........The local driveshaft shop suggested trying it. Ditto for my go to
guy for transmission work. Scouring the internet (confined to home as far as pandemic restrictions) indicated a consensus, 1" of "slide" of the transmission yoke on the output shaft should be considered minimum for a leaf spring car.......and shaft spline engagement should never be less than 3"....especially for a hard hitting drag car. A street car suspension would tolerate some less. SO.......I bit the bullet, and ordered up a new driveshaft.....no high zoot/big buck aluminum, DOM steel. FITS LIKE A GLOVE,and I now have 1 1/8" for dimension we are talking about. $300+ for a new shaft, 1350 u joints, sure beats what
could have been a BIG dollar "aw sh-t" for a try it. Short version.....I'd do what I could to increase your
measurement.

 

I will see if I can convince my wife to push on the bumper and see what happens. Thanks for the help.

 

Why wife would be more than willing to bounce on the rear bumper while my head was squeezed under a frame rail.

 

Not sure what joints you have, or what joints this has, but I think that a 1999 Crown Vic has a 55.5" driveshaft.