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Advice, shaft angles/solution

Posted: Tue Dec 02, 2008 2:32 pm
by spamwell
Okay coily 4-5 inch lift of so i have custom arms and stuff so there is no need to go on about the ohhhh don't do that to a coily thing.

anyways
I just recent did a gear driven transfer case conversion previous to this i did have slight vibrations but i managed to find a happy medium for road use by dropping the tranfser about 20mm on all mounts and probly like 10mm on the front mount so basically the transfer was tilted to give the tailshaft a better angle now this used to work because a standard coily chain case uses a longer jackshaft. BUT with the gear case the jackshaft is shorter and the angle made it angry so now i have a very slight vibration while driving all the time which i think is a combination of the tailshaft and jackshaft being upset and when in 4x4 i have worse vibrations because the front shaft is pretty bad.

also under power around certain corners the tailshaft vibrates.... aahhhaha basically its all messed up

here is some pictures to show what i mean.
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that kind of shows the cases current angle ( rear this way )
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tailshaft angle
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front shaft angle :bad-words:
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this also does not seem normal, front shaft slip yoke
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attempt at showing funny jackshaft angle...

now my plan so far to fix this is to lift the case to standard maybe as high as i can get it to make the jackshaft happy and maybe this will fix the front shaft slip yoke problem..obviously i would mount it level when i lift it, Now this will put a huge angle on the tailshaft my answer to this was making up a custom tailshaft out of a double cardian hilux jobbie.

okay opinions....pleease

Posted: Tue Dec 02, 2008 2:36 pm
by want33s
Looks like a WT transfer case to me... NO chain in there!
Dunno a lot about angles etc but from what I've heard a DC joint can't handle the same angle as a standard uni.

Jas.

Posted: Tue Dec 02, 2008 2:43 pm
by spamwell
lol i got gear and chain mixed up.......

used to be chain i will change the post :P

Posted: Tue Dec 02, 2008 3:19 pm
by ZUKPOWER
cardon joint on transfer end of both tailshafts and rotate diffs using castor wedges (1-2 degrees) to reduce angle at diff end of tailshafts. I use this set up in my SPOA 92 sierra and it does the trick nicely. oh you may need to modify the crossmember that the front tailshaft goes over to fit the cardon joint too

Posted: Tue Dec 02, 2008 4:00 pm
by spamwell
yeaahhh i maybe need to change my pinion angle that is a little bit trickier with a coily lol, the shafts look okay at the pinion though.

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angle at front diff

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angle at rear diff

Posted: Tue Dec 02, 2008 6:45 pm
by joeblow
the front shaft is usually something to live with, they were never set up from factory to handle high speed ( anything above say 40 k's an hour) and they were not designed for lots of lift. a double cardan joint puts a heap of weight on the output bearings of a zook t/case. i've found jimny tailshaft cv's work fine.

Posted: Tue Dec 02, 2008 6:55 pm
by spamwell
okay awesome, so you think a jimny cv and lifting the case should sort it out maybe :twisted:

Posted: Tue Dec 02, 2008 9:34 pm
by tazmanier
Just going to jump in here because I think it’s related. Obviously you can rotate the rear axle as far as you want with wedges / rewelding perches etc for a better uni angle. BUT what happens when you start rotating the front axle? Do you start to unevenly scrub tires? How much would it affect camber, castor and steering in general?
How far have people rotated there front axels and what have the results been???

Sorry spamwell, hope this is more of a addition than a hijack.

Posted: Tue Dec 02, 2008 10:40 pm
by alien
my tcase xmember has been "moulded" (ie: bashed) and then re-inforced to fit the hilux DC front and rear. my lift prodived about 4.5" lift on the SPOA and about 2" in spring lift at the leaves/mounts/shackles. my diff is rotated to suit the DC joint - so its pointing right up at the tcase essentially - steering is a touch lighter than before but i still had no worries passing the lane change test and have not seen any adverse effects as yet. I do think its slightly decreased my turning circle though - but thats more so the wheelbase extension.

Posted: Wed Dec 03, 2008 12:31 am
by spamwell
so alien when you did this where you able to lift the case and still get enough out of the dc joint in the rear to prevent vibration ? i do not have a body lift so i will not be lifting it far but i have heard that the better angle you can get out of the jackshaft you can get it smoother than factory.

also considering i will not have my rear diff moved back at all

Posted: Wed Dec 03, 2008 6:48 am
by lay80n
tazmanier wrote:Just going to jump in here because I think it’s related. Obviously you can rotate the rear axle as far as you want with wedges / rewelding perches etc for a better uni angle. BUT what happens when you start rotating the front axle? Do you start to unevenly scrub tires? How much would it affect camber, castor and steering in general?
How far have people rotated there front axels and what have the results been???

Sorry spamwell, hope this is more of a addition than a hijack.

When you rotate the front axle, you change the caster angle. Camber is not adjustable on zooks (or most live axles. You can get offset kingpin bearings etc but thats another story). If you rotate the diff to get a better pinion angle, you should cut the knuckles out and turn them to bring caster back to acceptable angles. This brings steering back into "normal".

Layto....

Posted: Wed Dec 03, 2008 8:23 am
by alien
spamwell wrote:so alien when you did this where you able to lift the case and still get enough out of the dc joint in the rear to prevent vibration ? i do not have a body lift so i will not be lifting it far but i have heard that the better angle you can get out of the jackshaft you can get it smoother than factory.

also considering i will not have my rear diff moved back at all
Not really - once the roctoy ring went in and beefed up mounts etc there wasnt much room - however my front diff is about 6" forward and rear is about 1" back. my tcase itself is quite tucked up, you can just see here:
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