Suspension / Driveline set-up questions

[RckyMntnKng]

Gentlemen,

Need some help understanding my next steps in the suspension and driveline department.

Ive added a set of 6" TC lift springs to my Jimmy (also 3" body lift), and used a 14bff rear and D60 front. (New perches on the 14bff were installed at the same angle as the stock ones, but moved in to match the new width)

Of course now, the stock slip-drivelines from the 205 wont mount up to the new axles unless there is changes in length and/or universal joint size.

This is where I get confused on my best options....

Do I need a transfer case drop kit?
Do I need to have my drivelines lengthened?
If I do, where are the measurments taken?
Do I need to use a shim w/certain degree to correct angle to the axles?
Do i get a conversion u-joint or better to upgrade the driveline itself to a larger 1 ton matching yoke size?

Someone please steer me in the right direction, it would be greatly appreciated. I want to do this right and have it drive like its 'sposed too when its done.
-RMK

[Burt4x4]

My .02c
I would have waited to weld the perches to the axle untill after you get a driveline installed. Just install the rear without welding the perches so you can adjust pinion angle as needed, no shims needed. If you do use shims make sure you buy STEEL, the alum ones will crack in time and spit out leaving your Ubolts hella loose (this happend to me and luckly I cought it and only suffered bent spring perches)
I would get new drivelines ~ HighAngle or TomWoods or local driveline shop that can build some beef for you with the correct yokes/u-joints.
To measure your driveline = Xfercase yoke to pumkin yoke (the half circle area were the Ujoint seats into) that in your installed length. The driveline must be able to move inward and outward when flexing.
I have never been a fan of droping the tranny/xfer case mounts, at only 6in of lift you should not have to do that, I wouldn't.

I use CV-joints on both my front and rear drivelines. With CV type you point the diff pumpkin straight to the xfer case. With non-CV driveline you have to make sure Xfercase yoke angle and pumkin yoke angle are the same so they cancel eachother out when spinning (within 3deg I think).
You can also run a flange at your xfer case the eliminates the u-joint type yoke, 4bolts instead...

This is a 1350CV type with flange mounting at the Xfer .120 wall tube. & 1410 Ujoint at the rear diff. from High Angle Drivline.

Hope this helps!
Good Luck

[RckyMntnKng]

Burt4x4, thanks really appreciate your help.

Im going to see what my angles are, and get my drivelines modd'ed up at a local driveline shop.

I know you want the yokes to be parallel (xfer and diff) so it seemed like if you put the perches at the same angle as stock, they would surely be parallel as from the factory, just at a steeper angle.

[Burt4x4]

"I know you want the yokes to be parallel (xfer and diff) so it seemed like if you put the perches at the same angle as stock, they would surely be parallel as from the factory, just at a steeper angle."

Yes, true for non CV type drivelines.
Going with a CV type alows you to rotate the pinion angle up for added ground clearance
One half dozen or another, 12 ways to skin a cat
hehehe
Good Luck

[RckyMntnKng]

So with a constant velocity joint dont they need to be pretty much pointed directly at each other? How did you angle the xfer case towards the pumpkin?

It sounds from your post above maybe you just need a straight shot from the pumpkin only if you go that route?....

[Burt4x4]

Ya the CV is at the xfer case so no need to change that angle at all. Then you just pioint the pinnion yoke/pumkin straight at the xfer. THe CV joint does all the majic to keep it vibration free

[RckyMntnKng]

Sounds great, maybe I should go that route myself. Thanks again man, you and VT always have the answers.

[swyfor5]

I'm watching, going to go this route myself. D60 in frt, and 14bt., in rear. Cool!

[RckyMntnKng]

How the hell do you measure the angle of your yokes to the accuracy of 2deg or less?

[Burt4x4]

Magnetic Angle Finder

[RckyMntnKng]

Wow...how much to rent that to me for a day?

[Burt4x4]

Good Morning
Do you have a harborfrieght or notherntool near you?
They are just a few bucks at thoes discount tool stores
Google it
I have a black one, that pic was pulled from google

[RckyMntnKng]

Found one last night at home depot!

Gonna pull my drivelines this weekend and grab some measurments, drop them off at a shop and see what they can do me for

[SeventyOne]

Question about the rotation of the pinion for a CV joint - how man degrees can you rotate a 14bolt rear end and still get adequate oiling?

How do you use the the angle finder to set the pinion rotation?

So you get the angle finder on the pinion with your perches loose and you start rotating it up...but what is going to tell you to stop rotating the pinion up?

[RckyMntnKng]

I can answer the angle question.....Whatever angle your Xfer case is at is what you try to match on your diff angle. The goal is to get them parallel as possible, so the rotational speed at both ends is the same....ie no harsh vibrations.

[Burt4x4]

True there is a limit to how high you can point the pinnion, I am not sure what the limit is as I don't run that much lift.
With the CV at the Xfer case you point the pinnion straight at the Xfer yoke.
I actually have my pinnion 3deg down (from straight at the xfer yoke) to help compensate for axle wrap with my 454 torque. If I ever get a anti-wrap bar I may move it up 3deg but that is not much more clearance so...

Non CV - bascially you set the angle finder on the xfer case yoke and take the reading, like 11 deg. then you rotate your pinion until it too reads 11deg.

You want to do this (CV or NonCV) with the weight of the truck on the springs so you get a true reading/placement. Then weld up yer perches.

[SeventyOne]

Originally Posted by RckyMntnKng

I can answer the angle question.....Whatever angle your Xfer case is at is what you try to match on your diff angle. The goal is to get them parallel as possible, so the rotational speed at both ends is the same....ie no harsh vibrations.

Right - but I plan on doing a CV style so I won't be matching angles I will be pointing my pinion up at the T-case so there essentially is no angular disparity between the pinion yoke angle and the driveshaft itself.

My question was how do I know I am within the "tolerance zone" of a CV shaft? How do I know I have rotated it enough or too far?

I guess I have been assuming there is no shaft between the T-case and pinion to know when you hit the right angle...Is this what I am missing? So use the stock shaft, set the angle, get new measurements for a new shaft?

[Burt4x4]

CV shaft is perrty forgiving but I would guess if you get out of the tolerance zone you will experance massive vibrations and pinnnion angle too high will mess with diff oil levels and splashablity or slingablity of the gear oil = HOT rearend

For mesurement without a shaft installed just point the pinnion at the xfer case and measure (cap center to cap center), when they make the shaft it will have in/out movemnt that will alow your mesurement some flexabilty, so it doesn't have to be a super perfect mesurement.

.02cents