shUt the fronT dOOr! ~ Front In Progress

[Infidel Edition]

So, I measured the angles on the front while dealing with the shims in back.
Now I understand why there was a bit if jibble when I put it in 4x4 and went down the highway...
The pinion and output shaft in front is almost lined up.
However, since it's a CV joint ~ They shouldn't be.

4016

4017

So now, I need to find an adjustable upper control arm to get the angle on the front correct ~ before I lift it.:spongebob:

[Infidel Edition]

question...
I want to make sure I'm understanding the angles for a CV joint.
The pinion should point directly at the TCase?
...so no angle on the front of the drive line ~ as the front U joint is for minor driving flex / the double joint next to theTCase is for the full angle of the drive line...
right?

[Firemanray]

question...
I want to make sure I'm understanding the angles for a CV joint.
The pinion should point directly at the TCase?
...so no angle on the front of the drive line ~ as the front U joint is for minor driving flex / the double joint next to theTCase is for the full angle of the drive line...
right?

You can't adjust the pinion angle on the front axle without messing up the castor adjustment in the steering. If you tilt the axle forward to "correct" the pinion angle you will possibly give your steering to much negative castor causing some really nasty handling problems. My 98 is lifted 6 inches without any adjustments to the front pinion angle and I have no problems with the driveline. The double joint at the transfercase takes care of any issues.

[Infidel Edition]

You can't adjust the pinion angle on the front axle without messing up the castor adjustment in the steering. If you tilt the axle forward to "correct" the pinion angle you will possibly give your steering to much negative castor causing some really nasty handling problems. My 98 is lifted 6 inches without any adjustments to the front pinion angle and I have no problems with the driveline. The double joint at the transfercase takes care of any issues.

I used blocks under the chassis to guesstimate the change in the front pinoin...
the additional 2" will make the TCase angle match the pinion.
wouldnt that cause extra vibration issues?

[Firemanray]

You won't get vibes from the front. The back is a different story. I've got a 1" transfer case drop w/ 6.5" of lift, stock driveshaft with minimal vibes, however, I've seen guys with 3 or 4" lift that have bad vibes. If you think about it SYE mod that is talked about a lot is basically installing a front driveshaft in the rear to eliminate the vibes. I say put the lift in and roll with it!! (I haven't read your thread about what you've done to the rear, I'll check it out).

Edit: There is nothing you're doing putting in a lift that can't be undone or modified later, best shot is to go for it and re-evaluate as needed.

[Infidel Edition]

i want to deal with the vib in back before I do the front.
the 2° shim I ordered came as 1.2° +/- leaving the rear pinion a 1° off.
its drivable, but the vib is definitely there.

...Front already has 2.5" springs installed. just holding on the spacer to make it match the back

[Firemanray]

Ok, went and read your other thread. If you haven't done a transfer case drop try it first. That might eliminate your vibes and it's CHEAP! You can re-locate the front brake line mounts and save having to replace the lines as well.

http://i223.photobucket.com/albums/dd11/firemanray21/brake_zps64da41df.jpg (http://s223.photobucket.com/user/firemanray21/media/brake_zps64da41df.jpg.html)
At 6.5" of lift fully flexed and turned my lines are just getting snug with this mod.

There is some more info in my build thread that might be helpful for you, I'm no expert but I know what has been successful for me. My son uses the Xj as a daily driver now with no problems.
http://www.xjtalk.com/showthread.php?t=5172



.

[Infidel Edition]

Wish I had a shop and still had my welder... They're very handy when you have room.

I picked up the front brake lines and have them installed. Have longer shocks ready to install.

But that vib in back is my current boggle.
Haven't broken away from the "honey-do" yet today to get out there. But will be tinkering soon.

Your build looks nice. Great ideas too

[Infidel Edition]

Hey, why can't I bolt in an H-Yoke on the axle end too?
...I mean, if I added another U-Joint to the mix, wouldn't that deal with the extra angle change while also allowing for me to keep my caster in line?
4025

... and wouldn't an H-Yoke from another XJ be the right size?

** asked by my inner nob :smiley-scared003:

[Infidel Edition]

I'm showing that the axle end u-joint is:
1.063" x 1.063" dia
3.217" x 3.217" length

the inner at t-case is:
1.063" x 1.063" dia
3.218" x 3.218" length

at t-case is:
1.063" x 1.063" dia
3.220" x 3.220" length

So the u-joint off the pinion is 0.003" shorter?
And the u-joint on off the drive shaft to pinion side would be 0.002" longer?

like this - 4026

[4.3LXJ]

Yes, that can be done, but you have to change the pinion yoke to accommodate it and do an SYE for the tcase end. The yokes are different

[Infidel Edition]

Yes, that can be done, but you have to change the pinion yoke to accommodate it and do an SYE for the tcase end. The yokes are different

Isn't the expansion/contract on the font shaft built into the drive shaft? Thus, there isn't a slip yoke on the front of the TCase?

[4.3LXJ]

Somehow I got the impression that we were talking rear shafts. Yes, the front shaft has a slip joint

[Firemanray]

I think you're overthinking this thing. The front shaft shouldn't require all these mods to work, even at the height you're at.

[Infidel Edition]

Somehow I got the impression that we were talking rear shafts. Yes, the front shaft has a slip joint

You had mentioned u-joints in rear as possible cause ofvibrations. And as I'm waiting for time to work on that... I'm pondering front suspension.

I'll most likely put the lift in and see how it rides before I go after upgrades to that. but thinking out loud helps me focus on the list ahead...

[Infidel Edition]

I think you're overthinking this thing. The front shaft shouldn't require all these mods to work, even at the height you're at.

I'm gonna do the lift and see how it goes.
but I also like to wrap my brain around possibilities in advance

[Infidel Edition]

even more of a PITA than the rear u-joint!
swapped the other hub (front) out today.
...I had picked up a pair of hubs months ago as the rt side was clunking. picked up a pair of u-jionts at same time...
swapped the bad hub and left the u-joint since it was a pain and didn't show any signs of an issue.
felt so good about getting the rear drive shaft done~ I decided to knock out the other hub and planned on the u-joints again...

nope!
gonna hold off and do a road trip to a friends place a few hundred miles south. then do those ~ and do the front drive shaft at the same time.

I know... I'm a wouss!

[Infidel Edition]

...a friend said to grab a ball joint press (C-clamp looking press) and pound out the u-joints with a hammer and then press new ones in with the press...

sounds like a definite maybe

[4.3LXJ]

Use the press for both jobs

[jimmixj]

Was thinking about your build...A driveshaft with a slipyoke is ALWAYS solid mounted at either end. The whole purpose of the Cardan joint, yoke-mounted, slip-yoke driveshaft in the front of an XJ is to eliminate the very problems you are trying to correct. In effect, that shaft should spin vibration free at almost any angle you are likely to put it under.
The rear SYE kit is designed to duplicate this arrangement in the rear driveshaft for the same reasons. In my experience you should be okay up to around 4-5" lift using t-case drop pucks and/or axle degree shims for the rear.
Couple of other thoughts...your described vibration in 4-wheel drive, on-road, may be nature of the 4wheel beast. Think attaching a steering wheel to your rear axle so you can feel directly everything it's doing back there. Also, looking at your pics, have you taken a good look at the condition of your axle-shaft joints? They tend to be seriously overlooked and you could have one partially seized. This would be amplified when actually engaged. Hope this helps...Keep on XJin!

[jimmixj]

Whhooops! Guess I should have read to the bottom of this thread! So, I'm from the Department of Redundancy Department!