Nth TT Install

[Crashnburn80]

Any late model TJ owner will tell you one of the akilies tendon of the 03-06 TJ is the Tcase ‘shovel’ skid plate. This thing is like a giant anchor plotting against your best intended lines.

The shovel:


Through diligent shopping on craigslist, I was able to obtain an Nth TT skid at a significant cost savings. I think this was pre-AEV, here is the current skid which was only recently made available again after AEV purchased Nth.
https://secure.aev-conversions.com/store/merchant.mvc?Screen=PROD&Product_Code=NTH14021AA&C ategory_Code=nthdegree

If you are not aware, the cost of the TT skid is a mere fraction of the total cost of a TT. Most TT skids will also require an SYE (for non-Rubicons), a CV driveshaft and rear adjustable upper control arms. If you have a moderate lift you will also likely need a CV trackbar bracket, even with an adjustable trackbar to prevent binding. These items alone can cost $850+, in addition to the skid plate.

The following covers my install experience installing the Nth TT skid on my 04 Rubicon equipped with a 5sp NV3550 trans.

First product impression of this skid was excellent. With three ¼” reinforcements running side to side plus the ¼” plate, this is one robust skid. The installation instructions are equally as impressive, with 13 pages of very detailed directions including color pics. They even go as far to take into account specific instructions for various setups, such as with a 1” BL or with a 1” MML you must complete this extra step or skip this step, ect.

Nth skid unmounted:


First major step was support the trans with a full sized 6 ton jack stand, then to remove the stock Tcase skid. The 6ton stand needs to be used for height, not capacity. Its recommended to torch the stock Tcase skid bolts (on the frame rails) in order to break the factory lock-tight, instead of breaking the welds holding the nut on the inside of the frame. Those JF threads come up all the time ‘help my Tcase skid bolt is spinning and wont come off’. Better safe than sorry, the $20 for a torch is well worth the avoided headache.

Torching the Tcase skid mounting bolts:


After heating those up and pulling them off I was surprised just how much thread locker was on there, seems like DC went to town with this stuff. It doesn’t surprise me at all that people break the welds instead of the thread locker. After pulling the stock skid off I was also surprised to see just how heavy the stock skid was, about 42 lbs according to Nth.

Since my skid was used it had the powder coat scraped off in a few places, so I hit it with a few coats of anti-rust Krylon black paint, this way it will also match my future Rokmen skid.

Stock skid vs new:


Stock:


Nth skid, note that because of the design it has points within the skid that are higher than the frame rail mounts, this does not allow the skid to lay flat like a traditional skid, so this comparison favors the stock skid. You can tell the sides of the Nth are still nearly 1” off the ground:


Next major step was to dimple the floor of the tub with the special tool. Well I purchased my skid used, and it came ‘special tool free’. The instructions refer an included chart that has various combos of BLs and MMLs to reference to see if you will need to dimple the tub. With my 1.25” BL I figured (hoped) I was in the clear since I also did not have this chart. (While its likely not the best practice I later accidentally dimpled my Tube using the Tcase and a floor jack).

There is a Tcase linkage drop bracket (much like included with the JKS BL) for those that are not running BLs. But since I had a 1.25” BL the instructions said to skip the bracket installation.

Here is where things start getting a little ‘creative’. The locker pumps are currently located behind the Tcase in the stock configuration. They need to be moved in front of the bulk of the Tcase, positioned along side the front driveshaft. This is an excellent location as they are still completely protected by the skid, but requires a little reworking of the wiring and air lines and modification of the bracket.

The locker pumps can be seen in their stock location in the upper right:


One side of the locker pump bracket has a 90 degree bend in it. To mount to the new location the same bolt holes will be used but the 90 degree bend must be straitened to 0 degrees, or no bend at all. There is a reinforcing arch in the bend that must be cut in order to straiten the bracket. An angle grinder makes extremely short work of this task.

Straitened locker pump bracket, with arch cut:

[Crashnburn80]

You then must remove all electrical connectors and air lines from the bracket. The bracket in addition to holding the pumps, also has 4 electrical connectors mounted to it, same PITA style as the hardtop uses for the rear window defroster. These connectors must be removed, they will later be zip tied to the fuel lines instead as 3 out of the 4 of them will not be able to reach the new bracket mounting location.

The following step is to rework the speedometer wiring. In its current location it passes right over the highest portion of the Tcase under the relatively lowest portion of the tub. After the Tcase is moved into its new location (much closer to the tub) the wiring harness will be smashed in this location. The instructions have you remove the factory harness tape and pull out the speedo wire, then move it out further up the harness so where there was once one ‘T’ in the harness there is now none, a new ‘T’ is now located further up the harness. Tape everything back up and its good to go, no wire cutting involved.

You can see the new tape in the pic, the speedo wire used to connect by the electrical tape on the left, its now been rerouted higher up on the harness. The harness will now be pushed down in front of the Tcase:

The factory harness is held in place on some tabs that stick up on the highest portions of the Tcase, the instructions have you remove the harness from these tabs so it doesn’t get smashed and slightly reroute it down the front instead of over the top. I added a few zip ties to keep the harness in its new location.

The locker pumps are then moved to their new home, along side the forward part of the Tcase. For configuring the wiring and new air lines, the pumps are temporarily hung off the fuel line mounts, right above their new location. This allows for all the wiring to easily be sorted in a neat fashion and the connectors that were unplugged earlier to be reconnected.

Locker pumps temporarily suspended from the fuel line mounts:


The only negative thing I have to say about this entire product (and its minor) is the locker pump hose rerouting. The directions have you ‘save’ air line by doing some creative modifications to your rear air hose to shorten the path , then cut the excess to reuse, or ‘gently pulling hose down from above the fuel tank, so you can cut off 3” then reattach it. WTF. This is a $500+ product and you cannot supply me with $0.15 of air hose! I had to reread the directions to be sure I was reading it right. The instructions reference using an included 3/16” and ¼” barbed unions to reconnect the air lines to extended them. I did not have these (my skid was used), so I had to make a trip to the auto parts store, while I was there I picked up some extra 3/16” and ¼” air hose so I didn’t need to monkey around with my current air line setup to save a few inches from the rear line.

Then you remove the old transmission mount, (which also has an integrated exhaust hanger) and transfer the exhaust hanger bushing to the new mount and install the new low profile mount to the tranny. This mount is in part what allows Nth to gain ground clearance some others don’t, while ground clearance is increased 2.75”, the Tcase is only raised 1.5”. With the low profile Nth mount, the isolators are moved from underneath the tranny (like stock) to either side of the tranny, allowing it to sit much closer to the skid. The 2 part isolator mount allows more control over the drivetrain, so under load the mounts can better resist the torque from the engine, to prevent movement that in the newly confined space may cause contact.

Stock mount with single isolator on the left, Nth low profile dual isolator mount on right:


In this step it also mentions to drill out the passenger side mount and stick the bolt from the bottom up with a nut (vs top down treading into the mount). For the life of me I could not see the logic here, so I skipped this. Whether it was a nut threaded on a bolt or just the bolt, either would have to be tightened down the same way. My kit was used and the threads were not drilled out, indicating that the PO had not done this as well. The passenger side it a bit of a PITA to get to once installed, but it is doable with a crescent wrench, though slow.

Once the high clearance tranny mount is installed, its time to mount the main skid. This definitely requires 2 people to lift and hold the skid in place while you attach the bolts.

Low profile mount installed, tight clearances between mount and tranny:


After everything is bolted up, there are several clearance checks. At least ¼” clearance must be present at all locations. In the trouble shooting area it mentions that if you have significantly more vibration at idle then something is likely making contact, and was not properly clearanced in this step.

The instructions then say to mount the locker pumps to the skid, this would have been a bit easier before it was all firmly bolted into position. I would highly recommend test fitting your locker pump bracket modification to the skid before you get to this step. Ideally this would be test fit while the TT is not yet mounted. Mine didn’t quite line up right, it would have been 1000x easier to fix earlier when neither wasn’t mounted on the Jeep. I was also missing the hardware for the new locker pump mount (purchased used remember), so a quick trip the hardware store and I was able to rig up something without to much fuss that did not require me to remove the pump bracket for further modification. Nth specifies ½” clearance is needed for the front driveshaft and you don’t want the locker bracket to contact the fuel lines on the frame rail.

Locker pumps viewed from the front of the Jeep, installed with makeshift hardware:


Orient and bolt up the isolators to the skid then tighten the tranny to the isolators (previously only hand tight). The passenger side requires a small miracle to get to but is doable.

You must then adjust the shifter linkage. I don’t know why but this gave me a large headache. Seems very strait forward but I must have adjusted the thing 20+ times before getting it satisfactory to my liking.

Dialed my pinion angle back in now that my Tcase sits higher, but now my axle is rotated far enough back (was already rotated back from the lift) that it will likely cause my trackbar to bind since I am not running a CV trackbar bracket. I placed an order for the JKS CV bracket which should be here before the end of the week.

The instructions then go on to describe the shifter clearance modification for 04+ transmission shifters. (Yes that is correct 04+, not 03 though it’s the same tranny). This is to prevent your tranny from popping out of gear in 1st, 3rd and 5th. Fortunately if running a 1” MML and BL you get to skip this step as well. My tranny actually shift better now than before the TT when I just had the BL. Since I have a 1” MML, 1.25” BL and the Nth TT raises the Tcase 1.5”, everything is pretty close to its factory position relative to each other.

And finally:

Remember the before pic:


After:


The clearance gain is huge. Running a 3" lift with 33s I have more ground clearance at the lowest point than a 4" lift running 35s with the stock Tcase skid. Lift your Jeep smarter, not higher.

I haven’t had a chance to try this out on the trails yet since the install, but my initial impressions are this is an outstanding quality product with some of the best documentation I have seen. I would highly recommend this product to anyone considering a TT, its very well thought out and after the install I would say it is worth its premium.

I finished this after midnight on a work night, I will try to get a couple more pics of the finalized install up soon.

Edit: New Images

Here are a couple side profile shots of the new skid I took while airing up at the end of the trail. These add a little more perspective.





The skid plate is barely visable.

[Crashnburn80]

The air hose modification does involve cutting the air lines. Since the new pump location is significantly ahead of the old location the front lines have a lot of excess and the rear line is way to short. I had no problem cutting the front line as the excess was rediculous and likely problematic if left uncut, but jimmying the rear line just seemed cheap. While cutting the air line may sound permanet, you can getting fittings to reconnect the cut hoses for about $0.75 at an autopart store and its as good as new. Its the same kind of fitting the factory uses at the air line junctions, so no real comprimise is being made.

As for wires, there is Zero wire cutting involved in this entire process. Just removing electrical tape and relocating the wires further up the harness and retaping.

[jtice]

EXCELLENT writeup, greatly appreciated.
I will be saving this page for sure, I absolutely love how this turned out.
This is on my list, right after the lift and tires.

~John

[Ichabod1960]

You need to submit this for the technical article/write-up section.

[Ares]

Originally Posted by Ichabod1960

You need to submit this for the technical article/write-up section.

You can get a free membership with that ya know...

It should be fun testing that out this weekend. But remember to BRING BACK MY JACK STAND!!!

[95BadBoy]

Crashnburn80

Very good write up, thanks for taking the time and sharing with us !!

[provelogear]

Might you have any info on the dimple process? I want to get rid of my 1" body lift as I like a low COG. I have an auto with Rock Trac 241. My TC makes contact with the tub without the BL.

Thanks!

[Crashnburn80]

Thanks for the comments listed above.

Originally Posted by provelogear

Might you have any info on the dimple process? I want to get rid of my 1" body lift as I like a low COG. I have an auto with Rock Trac 241. My TC makes contact with the tub without the BL.

Thanks!

The directions show the 'dimple tool' creating the dimple just to the left of the bolt above the red tag on the back of the Tcase. The Teraflex TT reuses the factory isolator I believe, so it lifts your Tcase at least 2". Even with dimpling the tub I do not think you will be able to do this without the BL, teraflex even mentions you will need a BL. The Nth skid only lifts the Tcase 1.5" with the low profile tranny mount, and combined with dimpling the tub leaves 1/4" clearance without a BL. So even if you dimpled the tub, you would still be 1/2" to tall with the teraflex skid and no BL. There is just not adaquate room to run the NP241 Tcase with the terraflex skid and no BL.

[provelogear]

Thanks for the info. I love the Nth TT. They weren't selling them when I got the Teraflex. Bummer! Thanks again for the write-up. Alright, seem like I can dimple then only use 5/8" BL that will help some. I'll also look at the tranny mount to see if I can change that. I might be able to gain some room there.

[Crashnburn80]

Updated with new side profile images at the end of post #2.

[JPP]

Hey Man, Nice Job. Looks a heck of a lot better on your Jeep than laying in my garage.

[stu'sjeep]

thanks for the great write up i will need it, i just finished stage 1 of my tummy tuck stage 2 is my MML, stage 3 is TT cant wait what is a good MML spacer or a whole motor mount like, Daystar,JKS or any of the other one's out there

[Crashnburn80]

Originally Posted by stu'sjeep

thanks for the great write up i will need it, i just finished stage 1 of my tummy tuck stage 2 is my MML, stage 3 is TT cant wait what is a good MML spacer or a whole motor mount like, Daystar,JKS or any of the other one's out there

Was stage 1 the BL? As per MML I would use one with rubber bushings, vs poly. MORE is currently the only MML offering rubber bushings that I know of, Browndog is supposed to be out with one soon. Otherwise that leaves the spacer lifts like JKS.

[stu'sjeep]

stage 1 was BL i see why you need it took me 4hrs myself