Driveshaft angles ?

[Rotazuk]

I have been told /read that its best to keep the output flange of the gearbox and the input flange of the diff parallel vertically , if you know what I mean ( forgot the term ) .

Anyway how much of an effect would having the output flange vertical ( 0 deg ) and the input flange at 10 deg at ride height . This is not a road legal machine anymore . Would the vibe , if any , be noticable ? Shaft is only 450mm between uj's so short .

Cheers
Chris

[Jafa]

All you'll ever need to know about such things here Chris
http://www.pirate4x4.com/tech/billavista/PR-shaft/index2.html

[wopass]

mine arent paralel and theres no vibes and no ill effects. as long as the U.Js are in phase it will be sweet

do it, you wont know the difference

[tgaguy1]

mine arent paralel and theres no vibes and no ill effects. as long as the U.Js are in phase it will be sweet

do it, you wont know the difference

Out of interest wopass, what is the approx angle of your pinion?

[wopass]

mine arent paralel and theres no vibes and no ill effects. as long as the U.Js are in phase it will be sweet

do it, you wont know the difference

Out of interest wopass, what is the approx angle of your pinion?

front or rear ?

im not really too sure to tell the truth, i think the rear is around 8-10deg and the front about 5-7ish ?

having the front tipped slightly has only slightly affected the on road characteristics but its not a high speed machine so its not even worth worying about,offroad you wouldnt notice it at all.

[tgaguy1]

mine aren't parallel and theres no vibes and no ill effects. as long as the U.Js are in phase it will be sweet

do it, you wont know the difference

Out of interest wopass, what is the approx angle of your pinion?

front or rear ?

I'm not really too sure to tell the truth, i think the rear is around 8-10deg and the front about 5-7ish ?

having the front tipped slightly has only slightly affected the on road characteristics but its not a high speed machine so its not even worth worrying about,off road you wouldn't notice it at all.

Mostly interested in the rear. As you say, off-road will have no problem with front as speed is generally not present and on-road the shaft will be stationary (2WD). The rear is the shaft that I am concerned with. yet to measure my pinion angle, though eyeball protractor would estimate a similar angle as yours. Thanks

Jase.

[Bulletproof]

My rear diff flange is 10.5 degrees and the gearbox 2.5 so there is 8 degrees difference and it has been like it for years with no ill effects.
I do grease the universals every week off-road and sometimes daily if in deep water.

Cheers Richard

[wopass]

My rear diff flange is 10.5 degrees and the gearbox 2.5 so there is 8 degrees difference and it has been like it for years with no ill effects.
I do grease the universals every week off-road and sometimes daily if in deep water.

Cheers Richard

yes grease, forgot to mention that, grease very often, before every trip normaly

[TJ]

Drivehshaft angle depends on whether it is a conventiona two joint driveshaft or a double cardan (CV style - three u-joint driveshaft). This is what both of them are supposed to look like:





If the size of the image is too big, just read this article as it explains it in a detailed manner.
http://www.4xshaft.com/driveline101.html

Worst case scenario is you will break the u-joint and spining driveshaft will put a few dents in your tub......

[KiwiBacon]

Basically.
Universal joints (aka hookes joints) put a torsional vibration into the driveshaft, if you have one on each end working at a similar angle (and installed in phase) then the second one cancels out the vibration so each drive flange turns smoothly without vibration.

Double Cardan Joints (DC joints) are two universal joints running together, if you put them at each end then you'll have no vibration problems. Well unless you do something really dumb (bent shafts, out of balance etc).

Constant velocity (CV) joints work like DC joints but are more compact. If you can find some with sufficient angle then you can use one at each end of your driveshafts and be free of vibrations for ever. The "something really dumb" exclusions above still apply.

[darinz]

The other thing to remember is a UJ should not be straight. It is common practice to not have the rear driveshaft setup to the text book. I have adjustable arms and haven't got my flanges parrallel like you should and it doesn't vibe. And that is at any speed with a lot of HP. The front which is also not correct doesn't vibe either but I've only tested that to about 140kph.
It is quite simple, keep the angles to a minimum, try and get the flanges close to the same angle and make sure you have good uj's and grease them often.

[KiwiBacon]

The other thing to remember is a UJ should not be straight.

I've heard this several times and I understand the reasoning behind it (keep the needle rollers moving so they stay lubed and prevent brinelling), but it's a minor consideration.
There are plenty of machines out there with UJ's running as straight as they can (if they knew it was perfectly straight, they wouldn't need to use UJ's) and there seems to be no issue with joint life.