Pinion Angle Opinions Needed

[cebra]

After lowering, my rear end pinion angle is 6 degrees up. My engine is at 7 degrees down. Is this ok? I am going to try to put new cab supports on and shim them a bit to try to get the motor at less of an angle (like 5 degrees). Would this be ok? I have read a lot you want to be within 1 to 2 degrees between the rear end/engine angles.

Anything more than that I am going to have to either get new motor mounts(the Dingo Slider related issues strike again) and move my perches or start hacking up my firewall. We mashed the pinch weld area up where the floor meets the firewall but this is where the trans is hitting. We have room behind this to move the trans up.

[mongocanfly]

as long as your angles are really close to the same it (should) be ok..think lifted 4x4..they usually have big angle numbers...3deg is what most try to acheive ...id try it and see what happens...you just dont want excessive angles as it causes u-joints to bind more..
i understand the diff angle changing while lowering...but why is your trans angle that much...did you set it that way ? to match rear? (ok ...just re-read and see your up against floorboard)
the IH truck im working on was 9deg from the factory, but i changed it to 3deg..

[cebra]

Originally Posted by mongocanfly

as long as your angles are really close to the same it (should) be ok..think lifted 4x4..they usually have big angle numbers...3deg is what most try to acheive ...id try it and see what happens...you just dont want excessive angles as it causes u-joints to bind more..
i understand the diff angle changing while lowering...but why is your trans angle that much...did you set it that way ? to match rear? (ok ...just re-read and see your up against floorboard)
the IH truck im working on was 9deg from the factory, but i changed it to 3deg..

The rear end is 6 degrees so the least I can go is 5 degrees on the motor then...would like to get close get closer to this than the 7 degrees I have now. We are putting in new cab supports and shims to see if I can get closer to 6 or 5. The firewall would be fairly significant surgery at this point since the bellhousing is what is hitting first.

[toddoky]

The absolute degree of the engine/trans inclination angle and the pinion angle is primarily important as to how it affects the U-joint working angles, which you cannot calculate without also measuring the angle of the driveshaft (actual part or a mock-up of one). You can have engine/trans and pinion angles that match each other exactly and still have excessive U-joint working angles due to extreme elevation differences between the components (i.e. lowered vehicles).

[mongocanfly]

You can use spring wedges to set the axle at any angle you need...but changing the trans angle is gonna be your biggest hurdle...I'm assuming this is the 71?...and has a low hump tunnel...