Outer Limits 4x4 Board

Im am trying to set up a tail shaft and need sum help
i have read a bit on pirate etc
they all say paralell t case ouput and pinion
i have seen shafts runing unis and not being parralel and they seem to have no dramas

ATM
i have -2 degree at t case output
- 3 at pinion
and a angle of 14 degree from t case output to tailshaft bout the same at the pinion

tailshaft is about a 1m long

will std hilux uni last at these angles or will it vibrate and fly to bits

im not so keen on using a cardinal shaft if i dont have to

thanks

whats the vertical separation from diff input to trans output?

The two unis will only compensate for each other (they are not constant velocity on their own ie they go faster slower faster slower faster slower etc) if they are parallel or at matched angles in the "broken back" arrangement.

Depending on how far off you are you'll get a lot of vibration or a little bit.

I cannot possibly explain it as well as this page does:

http://www.pirate4x4.com/tech/billavist ... ndex2.html

i have read that
they are paralell with both t case out put and pinion at -2 degrees to the horizontal exagertaed below

/
/

the shaft it 1m long pinion is 280mm below t case otput

thanks

front or rear?

MYV84B wrote:i have read that
they are paralell with both t case out put and pinion at -2 degrees to the horizontal exagertaed below

/
/

the shaft it 1m long pinion is 280mm below t case otput

thanks

Are you saying they look kind of like this:



?

Rear a assume?

Ideally they need to be on the same plane as what chimpboy states they are not a CV joint.

But

I have mine clocked to point directly at the trans outputs and have no problems other than a bit of high speed vibes in the front (only because my vertical separation is a fair whack more than 280mm.

This is good in a few ways, it keeps the pinion out of the way of rocks, raises the tail shaft.

I havnt had any problems other than a flogged out slip spline.

hey chimpboy yep it looks like that
with a 14 degree angle from line A to the tailshaft

yep rear
want to be able to run at hwy speeds tho
so i dont want any vibes

your angle 'a' will be almost level.

So your angle 'b' has to be almost level too


It dosnt realy matter though, ive had my car up to 140kmph and it has no vibrations from the rear...

Top angle is level, diff is rotated right up and pointing at the trans output.

No issues here

Z()LTAN wrote:your angle 'a' will be almost level.

So your angle 'b' has to be almost level too


It dosnt realy matter though, ive had my car up to 140kmph and it has no vibrations from the rear...

Top angle is level, diff is rotated right up and pointing at the trans output.

No issues here

I had a similar experiane on a SPOA sierra .
Pinion was pointed at the T\case no vibration issues at hiway speeds.

i'm running hilux double cardans front and rear, this means my pinion is pointing straight at the DC joint (DC is at tcase end of shafts).

No vibes at all with this setup, and its been bulletproof so far...

This might help ... http://www.highangledriveline.com/tech_ ... lines.html

you can also notch your shaft out of phase a spline or three either way to see if you can eliminate some of the inbalancing between both unis.

I did this with my first 4bys rear shaft, one spline round and it eliminated the small vibration i had completely.

Note: Range Rover classics run out of phase drive shafts from factory.

love_mud wrote:

Z()LTAN wrote:your angle 'a' will be almost level.

So your angle 'b' has to be almost level too


It dosnt realy matter though, ive had my car up to 140kmph and it has no vibrations from the rear...

Top angle is level, diff is rotated right up and pointing at the trans output.

No issues here

I had a similar experiane on a SPOA sierra .
Pinion was pointed at the T\case no vibration issues at hiway speeds.

Same, no issues...

For light vehicles, anything more than 8 degrees across a uni joint is not recommended. Heavy vehicles, the limit is 6 degrees.

If the angles on the 2 unis are only about one degree different to each other, the non-uniformity won't be big, so the vibration in the diff won't be bad but with such large angles, the tailshaft is going to shake like mad, assuming that the yokes don't bind and break the unis.

I'd look at pointing the diff pinion up so that the angles across the unis are equal, with the pinion being steeper than the tailshaft.

love_mud wrote:

Z()LTAN wrote:your angle 'a' will be almost level.

So your angle 'b' has to be almost level too


It dosnt realy matter though, ive had my car up to 140kmph and it has no vibrations from the rear...

Top angle is level, diff is rotated right up and pointing at the trans output.

No issues here

I had a similar experiane on a SPOA sierra .
Pinion was pointed at the T\case no vibration issues at hiway speeds.

i had mine setup with standard arms, so the diff had rotated itself up and the pinion angle was directly in ike with the tailshaft, then the change was at the top end, after reading all the suggestions, and wanting to get the diff back to level so the polyairs did their job better, i shortened the uppers and extended the lowers, and what have a got? vibration

thats with the transfer and diff on the same plane, vibrates from about 40-55kph.
i lengthened the uppers a little and vibrations arnt so bad, im gonna extend them a bit more, ie roll the pinion up a bit more, and see what happens, im thinking it will nearly eliminate the vibration if the last small adjustment was something to go by, what do people think the reasoning behind this is? just too much angle on the lower uni, even though it now matches the upper?

before it was not doing any work whatsoever.

the front also vibrates, but i dont drive with the hubs locked in so i dont care about that at the moment

looks like il suck it and see how it goes with 14degrees to get the answer

I am running the flanges paralell

we will go from this and make mods at a later date if needed

i remember reading somewhere it might have been in a 4wd action mag, about slasher uni's being able to handle high angle and high speed, could be worth looking into

Hey mate how did you go running at 14 degrees on the shaft?
I have the same angles on my rear tailshaft, parallel flanges on diff and transfer. I'm currently trying to sort out the vibration problems.
What set up did you go with?

Matt

MYV84B wrote:

im not so keen on using a cardinal shaft if i dont have to

thanks

You a choir boy?

He hasnt....
still getting finished off.

GRIMACE wrote:you can also notch your shaft out of phase a spline or three either way to see if you can eliminate some of the inbalancing between both unis.

I did this with my first 4bys rear shaft, one spline round and it eliminated the small vibration i had completely.

Note: Range Rover classics run out of phase drive shafts from factory.

This might explain why the front shaft I bought from a wrecked ZD30 Auto was skewed out of phase. It looked like it hadnt been tampered with but the unis were about 100 degrees out of phase. Is this normal for the GU ZD30 auto?
I am thinking maybe it was done to try and stop the 3 litre exploding itself

Sorry the thread highjack

Myv84b, One thing that you must consider for vibration issues is the changes in pinion angle during suspension movement or loads. I have never been able to get them perfect for all occasions.Just set it up and see how you go, and fiddle if need be. The only drama I had with the pinion and transfer flanges not being close to parralell was the uni at the transfer end seemed to always get sideways movement in it after a while and this caused vibration. Never broke anything. Since then I have run bigger unis off a different model and reset the pinions a bit closer to the correct angles ( much the same as your Chimps drawing)

As do (some?) Gwagens. However, I suggest it's an imprecise science.

For proof - Love_Mud's draiveshaft "that didn't vibrate at highway speeds" ( which I can attest to) exploded after a 6km long winding road constant uphill drive. The uni at diff end wasn't happy, and it was the constant cycling on and off power it didn't like.

I can attest it didn't vibrate at all at highway speed though.

14˚ is quite a lot of angle for a uni. (honestly) Factory installs try to not exceed 5˚, with 2˚ being considered ideal.

Might be fine, but just sayin' it's a long way from ideal.

Steve.

Gwagensteve wrote:As do (some?) Gwagens. However, I suggest it's an imprecise science.

For proof - Love_Mud's draiveshaft "that didn't vibrate at highway speeds" ( which I can attest to) exploded after a 6km long winding road constant uphill drive. The uni at diff end wasn't happy, and it was the constant cycling on and off power it didn't like.

I can attest it didn't vibrate at all at highway speed though.

14˚ is quite a lot of angle for a uni. (honestly) Factory installs try to not exceed 5˚, with 2˚ being considered ideal.

Might be fine, but just sayin' it's a long way from ideal.

Steve.

One of many reasons I would not ever bother with another SPOA.

Could you use landcruiser uni joints or later model hilux joints that are bigger to be able to run bigger angles at the uni?
Will go a double cardan if i have too, but like the simplicity of single uni's.

The 14* at the shaft is not the working angle of the joint, you subtract the angle of diff pinion or transfer flange to get the working angles.
I have 3* at transfer and 13* at shaft so uni working angle is 10*, and still vibrates.

Matt