ok my 49 f6, with a 8ba, 4 speed non schycronized trans and 2 speed eaton,'s frame is just about done

next step is to re install the engine trans drive shaft and rearend

the only thing is i have lowered it ALOT the engine/trans is at stock height and rearend is about 10" lower

i need to know how much can i tip the engine and back to cut down on the driveshaft angle???

how much neg/ pos pinion angle on the rearend is acceptable???

thanks in advance

 

Tipping the angle of the engine may work a little bit, but I don't think you'll be able to tilt it back a whole lot without running into other problems. When you start tilting the motor your going to throw off the angle of everything else on the motor. Mount the radiator and fan and see how much room you got before they hit and your bottom hoses still are in line.

You don't mention whether your still using the carrier bearing or omitting it. If your still using it then I'd keep the engine where it is and keep the mods from the carrier bearing back to the rearend.

I'm assuming you just lowed the frame on the axles by removing/changed some of the rear springs since your still using the two speed rear end. This is going to change the length of the drive shaft maybe more than the slip joint will allow. Mount the engine and drive shaft and see how it looks.

You can always loosen up the u-bolts on the rear end and rotate the rearend a little, but I dont think the angle will be a problem unless you drastically changed the frame setup.

 

The most used transmission to pinion angle is 2-4 degrees down for the tranny and a duplicate angle up for the pinion. If they are too much out of phase you will get a vibration at certain speeds.

 

Unless you are using constant velocity U Joints the angle of the engine center line and the pinion angle need to be the same. The common thing done in the 4X4 community is to tilt the rear axle up so the pinion is higher and inline with the driveline. I have seen this done many times and it can cause anywhere from an annoying harmonic vibration to constant breakage of the U joints. The standard U-Joints on a driveline work together and must be at the same angle in and out to work properly.

So to answer your question the pinion angle is fine as long as it matches the engine centerline and the drive-line does not exceed the maximum offset of the U-joints.

The guys at Drivelines Northwest have told me here in Seattle that a standard driveline should not be used over about 20 degrees. Unless you don't plan on using it for any high torque or long highway road trips. The more the angle the lower the life expectancy is for the U-joint.

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My Grandpa told me once that you have to learn by the mistakes of others because you will NOT live long enough to make them all yourself.