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Sierra tail shafts

Posted: Wed Aug 13, 2008 3:29 pm
by Petesarmy
can any one help me out, my tail shaft angles are to steep and the unis dont like it, does an one have any ideas i want to stay away from using a cv joint if its possible.

Posted: Wed Aug 13, 2008 3:38 pm
by ofr57
bigger uni's or push the wheel base out to reduce the angle

Posted: Wed Aug 13, 2008 3:44 pm
by badger
lower the t case or car

Posted: Wed Aug 13, 2008 3:47 pm
by Petesarmy
the front diff has already been moved foward and that is the one i have most troubble with.

Posted: Wed Aug 13, 2008 4:00 pm
by ofr57
i would say bigger uni's would be the way to go unless you drop the case .. which would be a prick i would think

Posted: Wed Aug 13, 2008 4:06 pm
by joeblow
depends on outputs and inputs being parrallel too. what excactly are the front uni's doin?

Posted: Wed Aug 13, 2008 4:07 pm
by grimbo
could it be the swb and the dual cases causing the tail shafts to be too short

Posted: Wed Aug 13, 2008 4:10 pm
by GRPABT1
Could cut the spring perches off and re-weld them so the diff angles up torwards the transfer.

Posted: Wed Aug 13, 2008 4:53 pm
by alien
hilux double cardan is almost a straight bolt in, then add some small spring wedges to change the diff angle a little?

Posted: Wed Aug 13, 2008 8:34 pm
by foolsp33d
GRPABT1 wrote:Could cut the spring perches off and re-weld them so the diff angles up torwards the transfer.
is a big no no if i recall correctly....

Posted: Wed Aug 13, 2008 8:47 pm
by joeblow
yes, lets fix the unis (which we don't use all the time) and rotate the diff and get some scary - castor stuff happenin. i recall a while ago there was a uni manufacturer(won't mention names) who was listing 1 litre stuff for the 1.3's. they will fit, but will chop out rather quickly, hence why i order vit ones for a 1.3 so i know i get the right stuff. otherwise we're gonna need more info or pics on your set-up.

Posted: Wed Aug 13, 2008 10:02 pm
by GRPABT1
Ok ok lets not flame without explaining. I know SFA about castor problems so anyone care to enlighten me?

Posted: Wed Aug 13, 2008 10:38 pm
by joeblow
not flamin grpabt1, just gettin some horrible thoughts of diffs rotated up combined with longer shackles...about negative gazzilian castor! proper way to do it is rotate the knuckles to the original position afterwards, but that should be a job for a pro. and we still don't have enough info of his probs. i know with my vehicle weight and torque my uni's probably don't like it either, but i don't ask their opinion, they will shut up and rotate. :lol:

Posted: Thu Aug 14, 2008 8:38 am
by sierrajim
grimbo wrote:could it be the swb and the dual cases causing the tail shafts to be too short
Front shaft, i think he said. Dual cases would only help front uni angle.

Can you take a picture under your car while it's on flat ground and post it up?

Posted: Sat Aug 16, 2008 4:30 pm
by GRPABT1
joeblow wrote:not flamin grpabt1, just gettin some horrible thoughts of diffs rotated up combined with longer shackles...about negative gazzilian castor! proper way to do it is rotate the knuckles to the original position afterwards, but that should be a job for a pro. and we still don't have enough info of his probs. i know with my vehicle weight and torque my uni's probably don't like it either, but i don't ask their opinion, they will shut up and rotate. :lol:
Rightio, I knew that some people do angle the diff up, never knew about rotating the knuckles. You learn something new everyday with outers :D

Posted: Sat Aug 16, 2008 7:25 pm
by ofr57
GRPABT1 wrote:
joeblow wrote:not flamin grpabt1, just gettin some horrible thoughts of diffs rotated up combined with longer shackles...about negative gazzilian castor! proper way to do it is rotate the knuckles to the original position afterwards, but that should be a job for a pro. and we still don't have enough info of his probs. i know with my vehicle weight and torque my uni's probably don't like it either, but i don't ask their opinion, they will shut up and rotate. :lol:
Rightio, I knew that some people do angle the diff up, never knew about rotating the knuckles. You learn something new everyday with outers :D
it more common to use wedges the rear .. less likly with the front as joe said its a big job to do right

Posted: Wed Aug 20, 2008 3:04 pm
by Petesarmy
i have a long wheel base, the problem that i have is that the two fork parts of the uni hit each other i will try to put a photo up if i can. as for using wedges i thought that only helped one uni.
i like the idea of hilux cardan joints what is involved in making one fit.

Posted: Wed Aug 20, 2008 3:11 pm
by Petesarmy
i forgot to add my set up is
86 lwb 1.3ltr sierra ute
spring over with 2" spring lift
35" simex
T-case reduction gears
Rear springs in the front
spaced tail shafts
extended chassis

Posted: Wed Aug 20, 2008 3:18 pm
by Gwagensteve
A Hilux double cardan joint won't allow more angle than two unis.

They're not designed to. The principle of their operation is to allow all the angle to be taken out at one end.

The correct way to align a shaft with a Double cardan joint on it is to take out all the angle on the end with one uni (i.e point the diff straight at the transfer) and then have all theh angle borne by the Cardan joint. This is because the double cardan joint is a type of constant velocity joint and vibrations will be caused if you have a steep uni angle at one and and a steep cardan angle at the other.

Basically, you need to lower the car, push the front axle forward, lower the car, cut and turn the knuckles to point the diff at the transfer and then use a double cardan joint, or lower the car, or lower the transfer, or fit a reverse rotation (high pinion) front diff or lower the car.

The front driveshaft on a sierra isn't really that short, I'm guessing you're really a bit tall.

Steve.

Posted: Wed Aug 20, 2008 3:23 pm
by Gwagensteve
Oh, I'll add that sierra uni's acutally allow a lot of angle for a stock uni- fa more than the US spicer style unis.

You could also move the transfer back to allow you to swap the driveshafts front to rear - adding length to the front and reducing the angle, but really, taking some height out will be the go.

Steve.

Posted: Wed Aug 20, 2008 3:52 pm
by lay80n
Hilux DC joints acutally have less angular opperating range than a singe uni.

Layto....

Posted: Wed Aug 20, 2008 4:01 pm
by Gwagensteve
I knew that as the case for MQ Double cardan joints but I wasn't sure for Hilux.

There you go....

Steve.

Posted: Wed Aug 20, 2008 4:03 pm
by lay80n
When we did the driveshafts for DRS's 40 i measured them up as we had them lying round. Pretty sure that the DC joint had less than a good single uni. That was compared to GQ and Landcruiser uni's. Didnt have a sierra one handy :oops:

Layto....

Posted: Wed Aug 20, 2008 4:08 pm
by Mudbits
If your running 35's your diff is probably rotating when you hit the gas and button off.
Maybe a top link could help?

Posted: Wed Aug 20, 2008 9:03 pm
by ajsr
maybe take out spacers and lengthen tail shafts less angle then??

Posted: Wed Aug 20, 2008 9:12 pm
by joeblow
yep....spring over....lifted springs.....gonna have drama's on the front uni's.

Posted: Wed Aug 20, 2008 10:01 pm
by MART
You;ll be able to fix the rear but you will need a cv in the front , why don't you want a front cv , I run one in my zuk and I've had no problems and my tailshaft is a home made one , Cheers Paul.

Posted: Thu Aug 21, 2008 8:15 pm
by NIK
I have lwb spoa on 35s and my front t/c out put is just aceptable. But I have flat rears up front. Do you really need the extra 2" from the spring lift ? With proper bumpstop spacing 35s fit mine fine it was only when I went to claws the side lugs caused my to chop out the inner guards for clearance.
Or Puals cv style drive shaft sounds good should be able to knock one up if you know some one that can weld.
Nik

Posted: Mon Sep 01, 2008 4:11 pm
by Petesarmy
cheers thanks it sounds like i will have to go the cv option. thanks for the hinters.

Posted: Mon Sep 01, 2008 7:49 pm
by 11_evl
will the C.V option work well in the rear with lots of travel?? strength wise i mean.
obviously balancing is a must.
would you put it at the transfer end or diff end?? its the rear transfer end im binding and spitting out!!