Tummy tuck with stock control arms and stock slip-yoke driveshaft

TRevs

TRevs

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Ok hear me out before you bring on the flame...

Phase I of the build has gone great; I replaced the original lift (2" springs + 2" rubber spacers, no BL) with 2.5" OME + 1.25" BL/1"MML). Still using stock CAs all around, stock driveshaft and slip yoke; NO vibes with either lift. Yes it's an LJ.

That was about 2.5 years ago and I'm very happy with it. BUT.... I'd like to improve ground clearance with a modest tummy tuck, which would also bring the shifter back to the original height.

Does anyone know if I can possibly remain vibe-free if I install something like the UCF Extra Clearance skid, while keeping the driveshaft and control arms stock? There were no vibes for the year I drove it with 4" of lift, and no MML; raising the skid would mean the driveshaft is seeing ~5" of lift, but now with a MML to help.
 
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I doubt you’ll squeak by, but why are you trying to avoid the unavoidable?

If you don’t know now, you’ll find out real soon.
 
JMT said:
I doubt you’ll squeak by, but why are you trying to avoid the unavoidable?
Click to expand...
Two reasons: time and money. I'm pretty happy with it as it is. It's taken me wherever I've wanted to go, and I don't really want to go down the road of adjustable arms and SYE, at least not anytime soon. I'm also refurbishing a YJ which is consuming a fair bit of the aforementioned resources.
 
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TRevs said:
Two reasons: time and money. I'm pretty happy with it as it is. It's taken me wherever I've wanted to go, and I don't really want to go down the road of adjustable arms and SYE, at least not anytime soon. I'm also refurbishing a YJ which is consuming a fair bit of the aforementioned resources.
Click to expand...

4” of driveline lift is right around that limit for vibes on LJs.

For a short bit, I ran 4” springs with stock CAs and tummy, and didn’t have vibes. Others have experienced the opposite. It’s really a gamble, every TJ is different.
 
PNW_LJ said:
4” of driveline lift is right around that limit for vibes on LJs.

For a short bit, I ran 4” springs with stock CAs and tummy, and didn’t have vibes. Others have experienced the opposite. It’s really a gamble, every TJ is different.
Click to expand...

How much did the replacement skid raise your T-case relative to the stock skid?
 
You won’t know till you try it. If you end up with vibes you could always just space the skid down a bit. Chances are you’ll come out ahead in clearance-wise. Can also install the UCF transmission mount which also lowers everything a bit.
 
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I had a very similar setup. LJ on OME 2.5" spring lift, 1.25" BL, 1"MML, OEM CAs, stock driveshaft, no vibes. I installed a UCF Extra Clearance skid, and had vibes. That skid gives about 2.125" extra clearance, but lifts the tranny by about 2.375". I added a DC driveshaft and Savvy upper rear CAs, which allowed the correct pinion tilt. Just the upper CAs got rid of the vibes, you don't have to tilt the pinion terribly far on an LJ.
 
TRevs said:
Two reasons: time and money. I'm pretty happy with it as it is. It's taken me wherever I've wanted to go, and I don't really want to go down the road of adjustable arms and SYE, at least not anytime soon. I'm also refurbishing a YJ which is consuming a fair bit of the aforementioned resources.
Click to expand...

You gotta pay to play…

Ditch the YJ and focus on the best platform ever.
 
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I put my full set of adjustable control arms in first, set at the same lengths as the OEM ones. After adding a UCF extra clearance skid I had to adjust them to get vibes out. Never really eliminated them with just the control arms. Put a SYE on and a Tom Woods DC driveshaft and adjusted it out to as smooth as it was before.

I also have 2.5” lift, 1.25” BL and 1“ MML On my LJ. I used a MOPAR transmission mount and modified the bracket the mount attaches to that has the exhaust hanger on it to lower the hanger part of it to keep exhaust out of the tub and off the upper rear control arm mount.

@AndyG came up with a way to use the UFC lo pro mount and not have vibes.
 
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OldBuzzard said:
I had a very similar setup. LJ on OME 2.5" spring lift, 1.25" BL, 1"MML, OEM CAs, stock driveshaft, no vibes. I installed a UCF Extra Clearance skid, and had vibes. That skid gives about 2.125" extra clearance, but lifts the tranny by about 2.375". I added a DC driveshaft and Savvy upper rear CAs, which allowed the correct pinion tilt. Just the upper CAs got rid of the vibes, you don't have to tilt the pinion terribly far on an LJ.
Click to expand...

Is that setup what you're running now? I'll have to look through your build thread.
 
Yes, I'm running that now, on 33s. I think it's the "final configuration" - until I change my mind, of course. This stuff starts on page 6.
 
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MountaineerTom said:
I put my full set of adjustable control arms in first, set at the same lengths as the OEM ones. After adding a UCF extra clearance skid I had to adjust them to get vibes out. Never really eliminated them with just the control arms. Put a SYE on and a Tom Woods DC driveshaft and adjusted it out to as smooth as it was before.

I also have 2.5” lift, 1.25” BL and 1“ MML On my LJ. I used a MOPAR transmission mount and modified the bracket the mount attaches to that has the exhaust hanger on it to lower the hanger part of it to keep exhaust out of the tub and off the upper rear control arm mount.

@AndyG came up with a way to use the UFC lo pro mount and not have vibes.
Click to expand...

I hadn't thought about the exhaust hanger issue; is all that in your build thread?
 
TRevs said:
Ok hear me out before you bring on the flame...

Phase I of the build has gone great; I replaced the original lift (2" springs + 2" rubber spacers, no BL) with 2.5" OME + 1.25" BL/1"MML).

Does anyone know if I can possibly remain vibe-free if I install something like the UCF Extra Clearance skid, while keeping the driveshaft and control arms stock? There were no vibes for the year I drove it with 4" of lift, and no MML; raising the skid would mean the driveshaft is seeing ~5" of lift, but now with a MML to help.
Click to expand...

How does 2.5" OME = 4" of lift?
Or 4" was the old lift.
So, 2.5 + raised skid = 5. Gotcha.
Carry on.
 
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I installed the Extra clearance skid, then spaced it down.
This allowed me to check for vibes and clearances as I moved it up incrementally.
Even if you have to run it spaced down for a while, it's still better than the shovel.
 
LONGJP2 said:
I installed the Extra clearance skid, then spaced it down.
This allowed me to check for vibes and clearances as I moved it up incrementally.
Even if you have to run it spaced down for a while, it's still better than the shovel.
Click to expand...

that's good advice.

the shovel sticks down so much, way more than even the YJ skid; I can't believe I haven't scraped it much or gotten stuck on it.
 
UCF_skid_13.jpg
 
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