New TJ, has a TC drop and a SYE, should I lose the TC drop?
- Thread starter sgtjdgelinas
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- sye t-case lift
Yes. If it has everything you mention, there's no need for a drop.
However, be prepared to adjust your rear pinion angle (via the adjustable control arms) once you lose the TC drop. It's possible that the driveshaft may not me long enough once the TC drop is removed.
You'll want to make sure the slip joint in the middle of the driveshaft sits in the middle of it's travel when the Jeep is on the ground, with the TC drop removed.
However, be prepared to adjust your rear pinion angle (via the adjustable control arms) once you lose the TC drop. It's possible that the driveshaft may not me long enough once the TC drop is removed.
You'll want to make sure the slip joint in the middle of the driveshaft sits in the middle of it's travel when the Jeep is on the ground, with the TC drop removed.
Agreed on all points. You would just need to lengthen the upper arms a half-turn or so to raise the pinion angle a tad once the tcase drop was removed.
OP
Couldn't tell you, I bought it from a used car lot so I couldn't ask the previous owner, the drop is made of square tubing, I didn't even notice it when I first looked at the jeep, it looks like part of the frame at a quick glance.
Please take a photo of your rear upper and lower control arms and post them here. If their length is not adjustable, the previous owner may have installed the SYE kit and CV driveshaft but was not able to properly adjust the rear pinion angle upward as required and thus had major vibrations. They may have had to add the tcase drop kit to get rid of the resulting vibrations.
X2 to Jerry's suggestion.
Make sure those control arms are adjustable, because if they aren't, you probably need that TC drop there for a reason.
Make sure those control arms are adjustable, because if they aren't, you probably need that TC drop there for a reason.
OP
A few observations:
1) Those are indeed adjustable control arms, but man-oh-man those things are rusted. You're going to need to soak those in PB Blaster (or similar) for at least 24 hours, because otherwise I doubt you'll even be able to adjust them.
2) Your slip joint on your driveshaft already looks like it's extended to it's max. Removing the TC drop and therefore pushing the TC up further, will extend the slip joint further, and probably cause it to reach the end of it's stroke, forcing you to get a new driveshaft (or destroy your TC anytime you go over a big bump or pothole). I think you may need to order a new driveshaft once it's all said and done. I could of course be wrong (you'd have to measure things once you removed the TC drop), but from what I can see visually, it seems like that slip joint is near the end of it's stroke.
1) Those are indeed adjustable control arms, but man-oh-man those things are rusted. You're going to need to soak those in PB Blaster (or similar) for at least 24 hours, because otherwise I doubt you'll even be able to adjust them.
2) Your slip joint on your driveshaft already looks like it's extended to it's max. Removing the TC drop and therefore pushing the TC up further, will extend the slip joint further, and probably cause it to reach the end of it's stroke, forcing you to get a new driveshaft (or destroy your TC anytime you go over a big bump or pothole). I think you may need to order a new driveshaft once it's all said and done. I could of course be wrong (you'd have to measure things once you removed the TC drop), but from what I can see visually, it seems like that slip joint is near the end of it's stroke.
OP
That's the only thing I'm worried about, it drives fine now, and it's much taller than the Cherokee I traded for it, so I'm not as concerned about clearance.
OP
Ok good. Those control arm threads are rusty so go out and buy a couple cans of Kroil which is a penetrating lubricant meant for situations like yours. NO, not WD-40. Liquid Wrench or Break-Free would be acceptable but Kroil is the best penetrant.
Start spraying the threads and lock nut and tcase bolt threads now, spray everything several times over a week to give it time to work its way past the rust and into the threads. Try to get some of the penetrant inside the frame above the tcase skidplate bolts so it can work in from the top too. The transfer case skidplate bolts are known to seize in place from rust and snap off or snap the nut inside the frame loose so spray it from top & bottom a bunch over a week to give it time to work into the threads. Trying to remove those bolts without having used the penetrant over at least several is not likely to work out well.
Once the drop is removed from the tcase skidplate, you want to adjust the upper rear control arms to make them slightly longer to raise the pinion angle. You shouldn't need to lengthen them by more than 1/2 to one full turn.
You need your pinion angle to be the same as the driveshaft angle when you're done. Like this...
The blue you see is a teflon coating baked onto the splines to lubricate its slip joint. It extends back underneath the female half of the driveshaft.
Start spraying the threads and lock nut and tcase bolt threads now, spray everything several times over a week to give it time to work its way past the rust and into the threads. Try to get some of the penetrant inside the frame above the tcase skidplate bolts so it can work in from the top too. The transfer case skidplate bolts are known to seize in place from rust and snap off or snap the nut inside the frame loose so spray it from top & bottom a bunch over a week to give it time to work into the threads. Trying to remove those bolts without having used the penetrant over at least several is not likely to work out well.
Once the drop is removed from the tcase skidplate, you want to adjust the upper rear control arms to make them slightly longer to raise the pinion angle. You shouldn't need to lengthen them by more than 1/2 to one full turn.
You need your pinion angle to be the same as the driveshaft angle when you're done. Like this...
The blue you see is a teflon coating baked onto the splines to lubricate its slip joint. It extends back underneath the female half of the driveshaft.
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My CV driveshaft I ordered from Tom Wood doesn't have a blue line. However, I have to imagine that blue line is indicative of something, and that "something" is probably the max extension as you suggested. Maybe someone else knows what that blue line means for sure? I'd probably remove the driveshaft (takes only 10 minutes) and see how much further the slip joint can extend past that blue line.
If that's the case, you'll want a new driveshaft, and you'll want to be very careful driving around with the existing one (if it is at it's max extension), because anytime you hit a bump, it's going to jam that thing right back into the transfer case. It might not do much at first, but it will only be a matter of time before it destroys your transfer case.
There's an explanation of that at the bottom of my last post above, just above the drawing.
I missed that!
Mine must have the blue line then and I missed it... It's been a while since I've been under there.
OP
Ok, so I'm going to pull that rear driveshaft to see how much more it can extend before I just remove the drop. The drop is 1 1/2 - 2 inches, so my question would be how much is that drop going to extend the driveshaft by? Is there a formula for calculating that or do you know by experience?
I'm not sure if there's a formula for calculating that (Jerry would know better than I would). However, I can tell you that when the vehicle is sitting on the ground, the slip joint should be in the middle (or at least close to the middle) of it's travel.
Like I said, it's fine if it's a little off, but I've seen Jeeps where the slip joint was at the furthest point of it's travel, and that's really, really bad.
Like I said, it's fine if it's a little off, but I've seen Jeeps where the slip joint was at the furthest point of it's travel, and that's really, really bad.