I have read a couple of the older forums relating to this but still have questions. I have a double Cardin shaft setup in a marine propulsion application. The u-joint offset angle is 2 degrees. I need to have spec tolerance for all four angles - vert offset, vert parallel, horizontal offset and horizontal parallel. Having all of these speced at 30 seconds is probably not possible with the tools available in the field. Anything less than a quarter of a degree is probably not attainable. Does anyone have experience with this?

Some of the best information available on Cardon's joints is at http://www.klein-gelenkwellen.de/en/tech/technis0e.htm. Look specifically at section 6, subsection "Permitted Tolerances."

Pietroski's (spelling) book on alignment I'm told also has a section but I've never seen it.

John from PA

It sounds as though you are saying you are physically restrained to attain anything closer than 15 minutes or 1/4 degree. Is this correct?

If that's the constraint, then that is what you will have to live with unless different provisions or design changes are made.

Size, speed and horsepower are factors. I assume high horsepower and low speed and large size.

You can write me for a tolerance chart; sampickens@sprintpcs.com and info or questions.

Basically your setup should entail checking for float in the joint - not to exceed 2 mils and run-outs - not to exceed 2 mils at the joint, centrality not to exceed 2 mils and 8 mils in the middle of the shaft (this is dependant on speed and length).

A U-joint moves about its center and doesn't accept horizontal misalignment to exceed the axial float - nil. Since each joint will accept only angular misalignment (hence two joints) the combination of two joints will accept horizontal misalignment.

The method of "long spacer coupling" alignment is basically simple and quick for this type of alignment measurement. It can be done with one indicator at each joint and make one turn recording every 90 degees. This can easily be plotted and all angular and horizontal offset will be seen. I have a sale on my textbook of ~327 pages w/software - see for sale items a few categories below.

Need more; write and I'll help all I can.

Thank you John. This is exactly what I needed. GC