Driveline angles

[flight_83]

I think I got my driveline angles all in spec and about as good as it can get. Just wanted to run the numbers by the community in case I’m not seeing it right. I have a gen2 coyote, TKX, and IRS. With a 5mm spacer under the Transmission I’ve got the output shaft angle -1.2, driveshaft +0.5, and diff +1.6. That results in 1.7 and 1.1 operating angles.

221754

[Skuzzy]

The most critical thing about the drive line angles is getting the output shaft and input pinion angles as close to parallel as possible AND keep the driveshaft from being straight inline with the output shaft and input pinion.

If the drive shaft is too straight, then the cups will not rotate on the axles of the u-joints which can cause then to freeze, unexpectedly. If the angles are not close enough to parallel with each other, then you risk inducing vibrations into the drive line which can cause a number of serious problems.

Ideally, as the drive shaft is so short, you want the angle to be at about 3 degrees with the output and input parallel to each other. It is critical to get that output and input as close to parallel as possible.

That is my two pennies worth.

[flight_83]

The most critical thing about the drive line angles is getting the output shaft and input pinion angles as close to parallel as possible AND keep the driveshaft from being straight inline with the output shaft and input pinion.

If the drive shaft is too straight, then the cups will not rotate on the axles of the u-joints which can cause then to freeze, unexpectedly. If the angles are not close enough to parallel with each other, then you risk inducing vibrations into the drive line which can cause a number of serious problems.

Ideally, as the drive shaft is so short, you want the angle to be at about 3 degrees with the output and input parallel to each other. It is critical to get that output and input as close to parallel as possible.

That is my two pennies worth.
Thanks for the response.
Isn’t 3 degrees the upper limit though? From what I read and what I was going off of is the operating angles should be at least 0.5 degrees and less than 3 degrees and the input/output within a half degree but opposite.

[Skuzzy]

Three degrees is a good limit, but I am happy once I get passed two degrees. The only reason for that angle is to keep the needle bearings rolling in the cups of the u-joint so they do not develop flat spots or seize up. The negative with that angle occurs when the input and output is not parallel. The further out of parallel they are, the more the negative impacts are multiplied by the angle, otherwise known as phasing errors.

It is a bit of a balancing act. The less the angle of the drive shaft, the less the phasing errors are multiplied, but the more likely u-joints will fail prematurely. The most likely failure, when the driveshaft angle is greater and the input and output are not quite parallel, is the rear transmission seal giving out first.

Just make sure the input and output are near perfect in parallel. Then worry about the angle of the driveshaft.

[Wizbangdoodle]

I watched this video on driveline angles and it's very informative and he illustrates his examples well.

https://youtu.be/YgNZfIR-8Ng