Driveline help needed

[Megatron451]

So I am doing an electric conversion for my 35 truck. I am at the place now to create the sub-frame for my electric motor. I can put whatever angle on it I want, but what angle and height should it be? What angle and height is the rear end? These are the variables when researching give conflicting information.

I would assume 2 degrees down on the transmission, 0 degrees on the drive line, and 2 degrees up on the rear end. I'm assuming about a 4 foot long drive-line.

For those that have done custom drive-lines, what do I need to account for? All the calculators account for a drive-line that I don't have yet, so it isn't the right calculator for what I'm trying to do.

I basically just want to know what angle I need to trans to be at, and what the rear end angle needs to be at. Then I can mount the motor/trans, then I can measure the specific distance for ordering the driveline.

Maybe this makes sense...?

[NAZ]

You can put the trans at any angle (within reason) that works for YOUR application. Most OEMs are ~2-3 degrees down at the rear of the trans but drag racers like to run zero degrees and I set-up my drag car with a slight angle down in front. The important angles are the relationship of the trans output shaft to the pinion angle and the operating angles of the u-joints. Ideally you would want the trans output shaft angle and the pinion angle to match under load (acceleration) to minimize out of phase vibration. The under load part is important and due to flex in the elastomer control arm bushings (or differential mounts on IRS) it is common to have some static offset to that angle so that under load when the differential rotates it ends up matching the trans output shaft angle. How much offset? Most use the by guess and by golly approach but you can test and get the exact angle needed for any particular configuration. And ~1-degree of operating angle will mitigate the chance of brinelling of the u-joint needle bearings as it will ensure that grease is continuously distributed and that the bearing tangents are not stationary on the races.

Not sure where you're located but for all my custom driveshafts I use Inland Empire: https://www.iedls.com/General_Requests_for_Quote

[ggunter]

In an ideal world the trans and rear are at the same angle. Most end up around 2.5 to3. degrees for the engine and if you can make the rear the same, the radians squared cancel each other out. Now the drive shaft should be within a degree of both the rear and the engine either up of down. So if your trans is down 2.5 and you rear is up 2.5 and you drive shaft is up 1.9 or 2. you are within a degree of your rear and engine. This should provide no vibration. You just don't want 2.5 engine and 2.on the rear and the drive shaft at 4.5. Your ride height is going to determine your drive shaft angle.