What is a tummy tuck?
Take a look under your Jeep Wrangler TJ and one of the first thing's you'll notice is that the transfer case hangs down really low (especially if you have a Rubicon model). A tummy tuck means that you're lifting the transfer case up into the body more and getting rid of that low hanging stock skid plate in favor of something flat, that doesn't hang down (or at least doesn't hang down as low as the stock skid plate).
Why do I need a tummy tuck?
Well, you don't need a tummy tuck, but if you do a lot of offroading in your TJ then at some point or another you're going to get your transfer case skid plate stuck on something, whether it be a rock, a log, etc.. With as low as the stock skid plate hands, most serious offroaders will agree that a tummy tuck is a necessity.
What do I need for a tummy tuck?
Depending on the Jeep you have and which route you intend on going you might need one or more of these for your tummy tuck:
Too much suspension lift for a tummy tuck?
One of the things I learned first hand when doing my own tummy tuck is that you have to be careful on the short wheelbase TJs (not the LJs). If you go over 4" of suspension lift and attempt to use an almost entirely flat skid plate (i.e. Savvy), your tucking that transfer case so far up there that it's almost the equivalent of having 7-8" of suspension lift. What I mean by that is that you have to rotate your rear pinion angle up so high inline with the driveshaft, that your rear track bar will be angled o far back that it will contact your fuel tank skid plate if you flex the suspension enough.
This can be fixed with custom fabrication, but I haven't seen any off-the-shelf kit that accounts for this. For me, at 4" of suspension lift with the Rokmen skid, my JKS rear track bar (with the track bar relocation bracket) is probably 1/4" away from contacting my fuel tank skid plate when the suspension is flexed out.
A friend of mine who has 4" of suspension lift did the Savvy skid plate, and his pinion angle was so high and so severe after the tummy tuck, that he either had to get a skid plate that hung a little lower (i.e. Rokmen), or lose some of the suspension lift to lessen the angle of the rear pinion / driveshaft.
On LJs this generally isn't an issue since you have much less severe rear driveshaft angles, and you can get away with a lot more. I'm only pointing this out because I want people to know what they're getting into. The TJ has a very short wheelbase, and therefore you really need to pay attention to driveshaft angles in the rear. There comes a point where that rear driveshaft is at such an extreme angle, that you're either going to be burning through driveshaft u-joints like crazy, experiencing a lot of vibrations that won't go away, or you're going to have your rear track bar contacting your gas tank skid.
Keep this in mind when doing a tummy tuck on your TJ!
Conclusion
Do the math on the products you need for your specific Jeep and ask yourself these questions:
Last but not least, if there are any errors or anything that needs to be added please let me know!
Take a look under your Jeep Wrangler TJ and one of the first thing's you'll notice is that the transfer case hangs down really low (especially if you have a Rubicon model). A tummy tuck means that you're lifting the transfer case up into the body more and getting rid of that low hanging stock skid plate in favor of something flat, that doesn't hang down (or at least doesn't hang down as low as the stock skid plate).
Why do I need a tummy tuck?
Well, you don't need a tummy tuck, but if you do a lot of offroading in your TJ then at some point or another you're going to get your transfer case skid plate stuck on something, whether it be a rock, a log, etc.. With as low as the stock skid plate hands, most serious offroaders will agree that a tummy tuck is a necessity.
What do I need for a tummy tuck?
Depending on the Jeep you have and which route you intend on going you might need one or more of these for your tummy tuck:
Body Lift- There are various routes to go with body lifts, but I always recommend a solid mount body lift such as Savvy, Rokmen, or others. Avoid the poly mount body lifts such as JKS.
Motor Mount Lift (MML) - Is needed when doing any high clearance transfercase skid on a Jeep that has a suspension lift of 2” or more. Stockers can usually get away with out it, but if you are doing a tummy tuck chances are you aren’t keeping the stock suspension height. The reason this needs to be done is when you are stuffing your tranny and tcase farther up you want to tilt the output shaft of the tcase down to help with the geometry you are messing with. By bringing the front of the engine up, you will be able to tilt the output shaft of the tcase down. There are various MMLs out there including M.O.R.E. Bombproof mounts.
Double Cardan Driveshaft - Is needed when doing any tummy tuck on a Jeep that has been lifted 1.5- 2” or more via its suspension. Stockers can usually get away without it, but if you are doing a tummy tuck chances are you aren’t keeping the stock suspension height. This will be needed regardless of whether you have a Rubicon or non-Rubicon. There are a few out there (Currie, Teraflex, ect.), but the only one that I would go with is a Tom Wood.
Slip Yoke Eliminator (SYE) - Is needed when doing any skid on a Jeep that has been lifted 1.5" or more via its suspension. Stockers can usually get away without it, but if you are doing a tummy tuck chances are you aren’t keeping the stock suspension height. If you have a Rubicon, you will not need one of these. Many people say that the Rubicon already has an SYE, but that is incorrect. It would have to have a slip yoke in the first place to elimininate it - Rubicons have fixed flange rear outputs. There are several good kits on the market such as Advance Adapters, JB Conversions, Rubicon Express, etc..
Rear upper adjustable control arms - Will be needed to rotate your pinion upward. There will be some fine tuning to eliminate driveshaft vibrations. Currie, Savvy and Metalcloak are the only ones I would consider personally. I run the Savvy adjustable control arms and personally think they are one of the best options available for the TJ.
Rear track bar relocation bracket - This angled bracket will be needed for your trackbar when rotating the pinion. With out this bracket your stock or adjustable trackbar will bind.
Rear shock relocation brackets - When rotating your pinion up, you will find that the can of your shock (if you have piston down, you may not have this problem) will rub the axle. If you're looking for maximum flex, this is a good time to consider shock mount relocation to use long travel shocks. Don't overthink this one. I just went with some basic Rough Country rear shock relocation brackets and they did the job just fine! The long term solution however, would be to outboard the rear shocks in my opinion.
Spring perch modifications - Will sometimes have to be done, but I personally have not seen a Jeep that has absolutely needed it. Rotating the pinion will cause the spring sit a bit different- resulting in the spring trying to arc...meaning the bumpstops will no longer align. This mod is not absolutely necessary with smaller lift heights, and mainly helps suspension geometry on taller lifts.
Transfer case bracket - Most people run into issues with the stock transfer case shifter assembly when doing a tummy tuck. In fact, most people have problems with it even when their TJ is bone stock. The bottom line is that the factory transfer case shifter assembly is a poorly engineered piece of garbage. Things will only get worse when you do a tummy tuck. The Savvy transfer case shifter is hands down the best transfer case shifter on the market for our TJs. Savvy took the Novak design and improved on it in several areas that make it an even better choice than the Novak shifter cable. There should be no question in your mind, Savvy is the way to go. Savvy makes a transfer case shifter for the NV241 Rubicon transfer case.
Skids - Last but not least you'll obviously need a new skid plate if you plan on doing a tummy tuck. There's ton of options out there. Some of the more popular options include Savvy, Nth Degree, UCF, and Rokmen. I personally run the Rokmen skid on my Rubicon and love it! It's an extremely durable skid for a great price.
Exhaust mod - After doing the tummy tuck you'll likely find that your exhaust is sitting right against the tub of your body (which is both loud and annoying), and sometimes the tailpipe will contact the gas tank skid. Bottom line, every instance of a tummy tuck I've seen has required some light exhaust modifications. For mine, I needed to cut a few inches off the exhaust hanger where it attaches to the bracket on the transmission mount. I also had to slightly adjust the tailpipe as it was rubbing against my gas tank skid after the install. I paid about $200 for all the exhaust work, but it only took them a few hours to complete. It's pretty easy and straight forward stuff.
Too much suspension lift for a tummy tuck?
One of the things I learned first hand when doing my own tummy tuck is that you have to be careful on the short wheelbase TJs (not the LJs). If you go over 4" of suspension lift and attempt to use an almost entirely flat skid plate (i.e. Savvy), your tucking that transfer case so far up there that it's almost the equivalent of having 7-8" of suspension lift. What I mean by that is that you have to rotate your rear pinion angle up so high inline with the driveshaft, that your rear track bar will be angled o far back that it will contact your fuel tank skid plate if you flex the suspension enough.
This can be fixed with custom fabrication, but I haven't seen any off-the-shelf kit that accounts for this. For me, at 4" of suspension lift with the Rokmen skid, my JKS rear track bar (with the track bar relocation bracket) is probably 1/4" away from contacting my fuel tank skid plate when the suspension is flexed out.
A friend of mine who has 4" of suspension lift did the Savvy skid plate, and his pinion angle was so high and so severe after the tummy tuck, that he either had to get a skid plate that hung a little lower (i.e. Rokmen), or lose some of the suspension lift to lessen the angle of the rear pinion / driveshaft.
On LJs this generally isn't an issue since you have much less severe rear driveshaft angles, and you can get away with a lot more. I'm only pointing this out because I want people to know what they're getting into. The TJ has a very short wheelbase, and therefore you really need to pay attention to driveshaft angles in the rear. There comes a point where that rear driveshaft is at such an extreme angle, that you're either going to be burning through driveshaft u-joints like crazy, experiencing a lot of vibrations that won't go away, or you're going to have your rear track bar contacting your gas tank skid.
Keep this in mind when doing a tummy tuck on your TJ!
Conclusion
Do the math on the products you need for your specific Jeep and ask yourself these questions:
- Can I afford a tummy tuck?
- Do you play in the rocks enough to justify one?
Last but not least, if there are any errors or anything that needs to be added please let me know!
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