karls10jk

I've seen one person chop off the C's and rotate them. Other housings can come corrected for caster and they basically do the same thing except there is less chance for error since they're all done up in jigs.

When you rotate the axle for pinion angle correction, you *should* also rotate the rest of your brackets and that's where people decide to live with the pinion angle or spring for a housing that's been corrected.

ronjenx

That would eliminate a major ingredient in the recipe for disaster. People aren't doing it because it's beyond most people's capabilities.

The frequent greasing of the joints, as mentioned above, is good advice. Some of the exploded t-cases had dry double cardans. However, a lot of the t-cases exploded not long after the drive shaft was installed.

The common factors among all the front t-case explosions were:

Lifted
Double cardan at the t-case
More then a couple degrees of pinion/drive shaft angle at the single cardan
Regeared
Highway speed
Feeling vibration, but ignoring it

Another factor may be how the double cardan is connected to the t-case. I don't recall all the specifics, but there were two different flanges one could use at the front output shaft. One would allow the double cardan to be closer to the t-case than the other. Having the joint farther away from the t-case will amplify the force of the vibrations, especially if the frequency hits a harmonic.

DKJEEP

There was an adapter that allowed you to not replace the factory yoke at the t-case. This one pushed it further out. The shaft I have replaces the yoke and keeps the double cardan closer to the t-case.

I understand if people had zero pinion angle correction and went 4" of lift and this happened. I cant remember all of the specifics from the stories but I am hoping that the pinion angle correction that comes with the 4" ome kit is enough to handle this. It does not sound like there is a way to 100% avoid this issue.

ronjenx

How does the OME pinion angle correction work? Is it adjustable control arms?

DKJEEP

Nope, way worse, lol. they have these offset washers that locate off of the existing hole in the axle and then you work some of the extra material out of the other side of the hole by using the washer as a guide.

Here is the quote from ARB.....

"Caster Correction & Driveline Kit:
To achieve a 4 to 5 degree caster correction it only requires 7mm longer arms or a bracket adjustment. For this small shift Old Man Emu has developed an offset washer which is the most cost effective solution. The offset washer is machined steel, fixed position, rectangular in shape and uses factory control arms and provides a reliable, solid solution to return the factory caster angle"





You dont hear anyone complaining about OME stuff so I assumed at the time I ordered it that it was going to be a decent option. One thing is for sure though and that is that these are NOT adjustable once installed. Also these are named "caster correction" parts and not pinion angle correction parts, my bad on calling them that earlier. It states that it gets you back to near stock caster position. So my new question is how is the pinion angle with stock caster on a 4" lift?

Front upper adjustable arms are cheap. I would rather do what is going to work best rather than cheap. I have the resources to cut the ends off of the axle and put them back on and I will do it if I have to.

DKJEEP

Just had another much cheaper and possibly labor saving thought. What about just installing this kit as is with the washers that set the caster back to stock setting, get some axle sleeves as they are cheap, cut the axle tubes between the center section and the ends, clean up the cut, then install tubes and adjust the pinion angle as needed, weld axle tubes back up using the sleeves to strengthen what you have done.

This I can do in the garage and it would leave me with near stock caster and all the bracketry for shock mounts and spring perches would be near stock location as well and I would have a perfect pinion angle for this lift so my double cardan shaft will live longer and greatly reduce the chance of blowing up the t-case.

SoK66

Ron pretty much explains it. Stock JK front housings have a 6 degree offset between caster & pinion angles. So, with 4 degrees caster you only have 2 degrees on the pinion, which works fine stock. Raise the rig via lift springs and the fun begins. Angle corrected aftermarket housings are generally in the 10 degree offset range, so in the same 4 degree caster scenario you'd have 6 degrees on the pinion. This can allow you to dial in maybe five & five and your front driveline angle should be nearly perfect and the vibrations will be gone. If you're a handy fabrication guy you can indeed cut the stock inner knuckles free and rotate them to get the 10 degree offset. A bit of a chore but it can be done, and for a time stronger inner "Cs" were available.

In the case of my '09, I originally did a 4" Teraflex kit with 3" springs. When I jumped to 4" springs a year later no amount of jiggering with the front angles worked to eliminate the driveline rumble at highway speeds. I'd unfortunately already sleeved & gusseted the housing and installed Pro Steers, so I concluded the only fix was manual hubs, which I sourced from Spyntec. Very expensive conversion, but they've totally worked the trick. Better handling, no vibrations and a slight improvement in mileage. I later fell into a great deal on a Teraflex R44 housing, which is angle corrected at 11 degrees. Still running the Spyntecs with no issues. If necessary I can leave the Spyntec Warn hubs locked and run like a stock JK and have no discernable vibration.

As has been pointed out the t-case grenading issue sems to have melted away. No way to tell, but there's the chance Spicer reinforced that front case to accomodate potential problems in stock trim. I don't know anyone who's had one of the later ones apart or done a comparison so this is just a guess on my part.

DKJEEP

Good info there. I already ordered the axle sleeves. They are relatively cheap at $110. I am definitely going to cut the axle tubes and not remove the "C's" from the ends. Those seem to be the same material as the center section and harder to weld on. Also this is MUCH easier to do and I wind up with my spring perches and other brackets still in a stock location. I am literally going to be able to fix this issue for $110 and some elbow grease. Of course while I am in there I'm doing gears and new seals and might as well do ball joints since these have 110k on them.

Either way I will take plenty of pics and show you guys how to do this.

kjeeper10

Rockslide makes a t-case brace as well. I threw one on .. Cheap insurance.