Outer Limits 4x4 Board

After ideas on tail shaft and pinion angles.

I have a SPOA and i get vibrations when trying to sit on a constant speed. It doesn't seem to be there while accelerating or engine breaking.
So i guess i could say it only does it when there is no load on the shaft.

Does anyone have any ideas?

Pics would really help.

Cheers!

try getting your tailshaft balanced

you may find your unis are shot, ot the slip joint is rooted

Tailshaft angles with SWB's and SPOA's can get pretty marginal, especially with lift springs. you could try some wedges to roll the rear diff up a little bit to relieve the angle at the diff a bit. Did you set up the spring pads parallel to the old SPUA pad?

I think that most SPOA conversions roll the diff up a little bit to help.

Are you still running a stock length rear driveshaft? If so, it may be overextended, meaning it will be getting some play at the slip joint. this will cause vibration if it is lightly loaded.

As per the other posts, check the condition of the uni's, however the car is set up, the uni's will be running at a fair angle and they will have reduced life.

I have seen SPOA sierras bind their rear driveshafts when engine braking off road so it is really important to get them spot on.

ive got mine a few degrees under parrallel with 20mm spacers seems to work fairly vib free

by parallel i mean parallel to drive shaft on diff end

So do most people have their pinion angle close to the same as the drive shaft, so it's like a straight line?

Heard that the diff and tcase flanges were to be within a couple of degrees of each other.

apparently they have to be a few degrees off to prevent uni siez ?

I have wide track diffs and it looks as if the pads were set up at the same angle as the originals. BIG angles on both ends of the drive shaft!!!!!

Does anyone have pics of their angles?

Brad.

illl just go and take a pic

Should be aiming for parallel under load.

are you running lift springs? are you running a track bar?

maybe it's just too much angle with your current height.

redzook wrote:illl just go and take a pic

i cant get the digi workin

thought you couldn,t find ya car !!!!
it took you so long !!!

It has 2 inch lifted springs and i don,t have a track bar.

Wondering if i should rotate the diff so the diff pinion and tail shaft are close to in line and go with a cardinal joint on the tcase end.

Thanks any way redzook. By the way good drive. I don't know the track at all but the picks look great!

Mine was set up with the pinion pointed strait at the T/case, seemed to work OK, but without a torque rod thingy, you will bind the uni's under offroading conditions. (with the pinion pointed up you will bind the uni's easier under power as the uni's are already closer)

love_mud wrote:Mine was set up with the pinion pointed strait at the T/case, seemed to work OK, but without a torque rod thingy, you will bind the uni's under offroading conditions. (with the pinion pointed up you will bind the uni's easier under power as the uni's are already closer)

What do you mean by bind the uni? Mine have been ground out to allow for bigger angles if that helps.

Thanks for your help guys. I'll get some big wedges made and if that helps i'll rotate the spring perches.

ive got the same problem but mine isnt shaking its only whining. and mines SPUA!! Diff was recently reconditioned (New Bearings, collapsable spacer, seals etc) and ive only noticed it since then. I reckon my tailshaft between the transmission and t case is off balance cause i had to take it out to do the rear gearbox seal and couldnt work out which way it went when putting it back in. made marks and all that shit but when the time came to put it back in they made no sense!! Funny that!!

hey guys with mine i rotated my diffs to 5 degrees positive and left it at that. on the rear i run a hilux shaft with cardan joint, and on the front i run a normal hilux shaft. with the added bonus being the bigger unis which take alot more angle. smaller unis will only take so much angle as they have a limit, so if u grind ur yokes out you will still chop out unis...

i had the same problem between gears(shifting-no load on splines)ended up getting a double carden,new splines and keeping the diff end uni dead straight by using wedges to rotate the diff up,cheers