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So you want a Tummy Tuck...

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#1 · (Edited by Moderator)
So you want a Tummy Tuck

I am aware there is a thread out there similar to this in the fact that it list some of the facts about several skids on the market, but this one is complete and it just for setting up a tummy tuck. This thread will be devoted to the TJ, as this is the TJ Technical Forum and that is what most have on here. LJ's are a bit different when it comes to driveshaft requirements, but most principles still apply.

Everyone thinks they need a tummy tuck these days. They are very useful off road and even make a TJ look better because you are no longer seeing the ugly shovel. A tummy tuck takes more than just several hundred bucks to buy one, there are other things that have to be dealt with. Most decide they don't need one when they figure out how much it will cost. The stock skid not the stoutest, but will hold up to mild wheeling, and comes in at 41.5 lbs.

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:

1" Body Lift- All depends on how much hammering (or 'modification') you want to do on the transmission tunnel. There are various routes to go with body lifts which include JKS ($135), Daystar, Performance Accessories, Currie, etc. It seems like everyone is scared to do one of these[, whether it be due to looks or difficulty of installation.] I have seen at least 30 posts asking if they can get away with doing such and such skid without one. A lot of people that are concerned with performance think that every Jeep should have came with one from the factory. The 1" body lift is hardly noticeable and will allow other mods like a high clearance gas tank skid. They also help lift the body without changing the COG very much, reducing the amount of bumpstop you need to clear a given tire size.

Motor Mount Lift (MML)- Is needed when doing any high clearance t-case 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 ways to lift your motor which include JKS(spacers-$60), Brown Dog(full replacement-$84), and M.O.R.E(full replacement-$139). If you choose new motor mounts instead of the spacers, get the rubber bushing versions to reduce engine vibrations. Poly bushings **can** transmit more engine vibrations, but they greatly reduce engine movement and will not degrade as fast as rubber. Rubber's lifespan is usually a few decades...so its your choice.

Double Cardan Driveshaft- Is needed when doing any skid 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. Will be needed, Rubicon or not. There are a few out there (Currie, Teraflex, ect, but only one that I would go with- Tom Woods which run around $315 (Quadratec).

Slip Yoke Eliminator (SYE)- Is needed when doing any skid 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. 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 ($270 Quadratec), JB Conversions($300-$400), Rubicon Express ($330)

Rear upper adjustable control arms- Will be needed to rotate your pinion upward. There will be some fine tuning to eliminate driveshaft vibrations. Rokmen and Currie are the only ones I would consider when dropping money on them as of right now. Rokmen-$249. Currie- ($229)

More info on SYE/CV shafts & pinion angle: http://www.jeepforum.com/forum/f9/what-cv-shaft-why-do-i-want-one-854790/

CV trackbar 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. Rubicon Express-$70

Rear lower shock mount extenders- 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. Some extensions like those from Currie-$30 will get the job done. If you're looking for maximum flex, this is a good time to consider shock mount relocation to use long travel shocks - read here: http://www.jeepforum.com/forum/f9/low-lift-long-shocks-diy-shock-shifters-whats-advantage-852221/

Spring perch modications- 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.
Read Humbolt's write up: http://www.jeepforum.com/forum/f9/outboarding-rear-shocks-upper-spring-bucket-relocation-929056/
Also see this thread: http://www.jeepforum.com/forum/f9/rear-spring-relocator-kit-856163/

Transfer case bracket- Anyone that knows transfer case brackets know that Novak ($150) is in the top of the game. There are others out there like the one from Advance Adapters or Skyjacker that are cheaper alternatives, but just doesn't work like the Novak. The stock shift lever can often be used when a TT is install in conjunction with a MML & BL, since these keep the drivetrain and accessory angles as close to stock as possible.

Skids

Kilby- I really haven't seen many people run this skid, but looks to be well made. Skid is made from 3/16" bare steel (you will need to paint or powdercoat it). Skid can be done without a body lift. Incorporates Rubicon locker pump mount. Clearance gains?
Weight- 38lbs
Price- $340

AEV- I haven't seen one complaint with this skid. Skid is made from 1/4'' gusseted steel and 2.75" more clearance is possible with this skid, but where the tcase sits it has less clearance. Uses a super low-profile tranny mount. Skid comes with flat bolts that cannot hang up on rocks and comes powdercoated. Skid can be done without a body lift, but 42RLE auto owners might need to 'modify' the firewall/trans tunnel. Incorporates Rubicon locker pump mount.
Weight- ?
Price- $529

Rokmen- Beautiful skid, best tig welding I've seen for mass production Skid is made from 1/4" laser cut bare steel (you paint it) that is CNC formed. Gains of 2.25" will be seen. Uses stock tranny mount. Body lift is suggested. I have seen the back of this skid bend from mild wheeling, but this skid provides one of the best all around deals.
Weight-?
Price- $344. +$20 for Rubicon locker pump mount.

Clayton- This skid uses the 2 piece design. I haven't seen many people use this skid. It might have something to do with it only advertising .5" gain for 97-02 and 1" gain for 03-06 Wranglers. Uses 3/16" steel for the cradle and 1/4" for the skid plate. Comes with a finish, but not specific. Works with their long arm set up if you ever decide to go that route.

Price- $475
Weight- ?

Skyjacker- Zinc coated skid made from 3/16" steel with gusseted corners. Comes with shifter bracket. Gain in clearance is not specified. Only made for 97-02 Wranglers. Body lift required
Price- $410 (Quadratec)
Weight-?

Teraflex- Up to 2 3/8" gain. Made from 3/16" steel. Body lift recommended for Rubicon. Comes with finish, but not specific. Comes with a 5/8" MML.
Price- $450 + Rubicon compressor mount for Rubicons
Weight- 79 lbs

Under Cover Fabworks- Made for 97-06 Wranglers, the skid is fabricated from 3/16" thick carbon steel plate (with optional upgrade to 1/4" plate). The parts were designed in 3D CAD software and laser cut then bent on a CNC press brake. The UCF Transfer Case Skid Plate is reinforced in the middle of the skid from one side to the other with a stiffening channel/transmission mount. The front and rear edges are ramped to increase strength and aid in sliding over obstacles. Clearance gains of about 2" over the factory skid plate will be seen. The total height of this skid is about 2". Skid comes bare and does not include hardware.
Price- $169 for 3/16 and $229 for 1/4"
Weight- 60lbs (Im guessing for the 1/4")
New:
Under Cover Fabworks has released a skid that has the exact characteristics of the steel skids they produce, except they will be offered in 304 Stainless and 6061-T6 Aluminum.
Price- $329: 1/4" Aluminum
Weight-26 lbs

33 Engineering- As far as I know they are out of business, if you can still find one it is the 1 of only skid made that can be dropped without supporting the tranny. It uses a crossmember and a skid that is bolted to it. 2.75" of added clearance are said to be gained from the skid. that was ordered bare or powdered. 1" body lift required.

Never buy anything directly from these guys or anything that will be drop shipped from them. Buy from people that have the skid in stock or do not buy at all.
http://www.jeepforum.com/forum/f176/offroadtoystore-33-engineering-kaput-so-my-dough-811839/
http://www.jeepforum.com/forum/f176/dont-buy-anything-offroadtoystore-com-809307/index2.html
Offroad Toy Store Reviews

Price-?
Weight-?

Jeepmedic-. Although no longer in business, you may be able to find one used. Skid is made from 1/4" gusseted steel with quality powdercoating. Gains of 2.25" will be seen from this beefy skid. Reuses stock trans mount and includes Rubicon locker pump mount. This was regarded as the best skid on the market at the time JeepMedic closed.

Price - ~$200-400 used in good condition
Weight-?

Goferit- Im not sure if these guys are still around. There isn't much info about these skids and not many people run them. Steel thickness? Clearance?
Price?
Weight?

Savvy Offroad- Everyone is talking about this skid. Will be made from aluminum and there has been word that it will be a completely flat skid. This not only will have the highest clearance, it will have a chance (with the UCF skid) to be the lightest of any skid listed. Savvy has some competitive pricing so I like most people I can wait to see this thing. You will most defiantly have to run a body lift if this skid is flat or do some serious modding to the tub.
Clearance gain-?
Price-?
Weight-?

*Exhaust mod- For every skid listed you will likely have to mod your exhaust so it will not contact the skid and or the lower control arm. Some people can get this done by themselves while others need to go to an exhaust shop. Going to an exhaust shop usually isn't too expensive for this fairly simple mod.

*BL or No-Some skids say body lift required or recommended, but can be done with out with enough hammering on the tranny tunnel as stated in the beginning. While most skids can be done without a body lift, you are tucking the transfer case closer to the body. There will be more noise as well as more heat coming from the exhaust as well as the tcase transferred to the floor board. Keep in mind - with a tummy tuck you are lifting the entire drivetrain up 2" or more - meaning you're changing the output shaft angle and you need to make room for the relocated components. The easiest way to do this is a 1" MML + BL.

*Prices are from the manufacturer unless stated otherwise

Do the math on the products you need for your specific Jeep, can you afford a Tummy Tuck?? Do you play in the rocks enough to justify one? If there are any errors or anything that needs to be added, let me know. Thanks. Thank you Unlimited04 for your help.
 
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#197 ·
Ok... So I was proposed an interesting offer. Now I need to figure out if I really need all of the things listed in the first post. The biggest question I have is about the sye/ds associated stuff. My jeep sits at stock height, and 2.5" of lift at the belly can't really be that much that I need to worry about it, is it? I would say I should be fine without anything to reduce vibes. If I do have vibes 1"mml should take care of that right? The UCF website suggests a 1" BL to help clearance, but I would rather dimple the tunnel for now if needed. my main reason for getting a TT RIGHT NOW as in before any building occurs would be that I need to get rid of the acursed 42rle stocker vibe. When I start building I would opt for a savvier solution that gets more clearance and is lighter.


The forum was also just down for a minute :(
 
#199 · (Edited)
Well... after receiving a PM from undercover fab, the skid only raises the drive train about 1.5". That is such a little mount that there should be no issues with needing a BL, or sye and associated stuffs. I would snap one up for my next few years before a proper one went in, I just need to see if I can get away with spending some more money on the Jeep now. Its real owner was flipping out that I spent an extra $20 in gas. I will just have to take her for a ride and point out the horrible annoyance.
 
#204 ·
I recently installed the skyjacker TT and I am slightly concerned that there are only two mounting holes on each side of the skid? It is not what they have in their pic. Also my transmission bolts now hang below the skid. anyone else have one of these.
 
#206 ·
Rear lower shock mount extenders- Anybody had to run these with nth degree tt? I have 3" suspension lift and 1" BL and all JKS arms so adjusting is not a problem. I am very close to pulling the trigger but don't want to mess with shock shifters.

To really do tummy tuck on my Jeep right now I only need the TT and DS. But just want to verify I am not going to run into any surprise.
 
#207 ·
Rear lower shock mount extenders- Anybody had to run these with nth degree tt? I have 3" suspension lift and 1" BL and all JKS arms so adjusting is not a problem. I am very close to pulling the trigger but don't want to mess with shock shifters.

To really do tummy tuck on my Jeep right now I only need the TT and DS. But just want to verify I am not going to run into any surprise.
It all depends how much your pinion has to be rotated and how thick the can of your shock is. You probably will need it, having a TJ with a 3" lift and all. They are a really easy mod, 1 hole needs to be drilled and are very very easy to istall.
 
#211 ·
Okay...so from what i have been able to research, 1/4" thick 6061-T6 Aluminum plate is not quite as strong at 1/4" carbon steel...close, but not quite as strong. On a good note it won't rust and it will flex a bit to absorb the shock from rocks...... On a bad note, it will eventually corrode and still isn't as strong as the steel.

So....weight aside, why would anybody want the aluminum over carbon steel or stainless steel?
 
#213 ·
x2, but I like the way that Blaine put it. It isn't about overbuilding the beefiest thing to have bragging rights. The best product is the one that is the best designed to hit that sweetspot between getting the job done, and having a light product that isn't wasteful.

His wording is better, but the philoshophy is there.
 
#214 ·
If you have stiffening ribs on the aluminum it wont flex much, you wont have to add much in the way of stiffening ribs to get comparable strength out of the aluminum, but you get the benifit of less weight. To alot of us weight is important, if for nothing else, try laying under your jeep and bolting on a steel TT skid, i bet you struggle with it, but an aluminum one you could do without a jack.



Pay no attention to grammatical errors please!!! :)
 
#215 ·
Is that aluminum going to corode as bad as most aluminum products do? Its not worth spending the money and shaving the weight if its gonna look like poo in a year or two anyways.....

Is the aluminum going to be strong enough to smack a rock hard and center without bending and buckling?
 
#217 ·
Is that aluminum going to corode as bad as most aluminum products do? Its not worth spending the money and shaving the weight if its gonna look like poo in a year or two anyways.....

Is the aluminum going to be strong enough to smack a rock hard and center without bending and buckling?
no,
i agree,
yes, it will most likely be guaranteed like the rest of their products

read some of this link

http://asm.matweb.com/search/SpecificMaterial.asp?bassnum=MA6061T6

Would you not paint the aluminum skid? self etching primer and some top coat would do it some good.
 
#216 ·
I guess this the time to clear up some issues that people have with aluminum. One, the most important part of this whole thing is that not all Aluminum is the same aluminum. This aluminum at 1/4" is about as strong as 3/16" steel, and it is much stronger per pound. I bet someone can find the numbers. This is much stronger than anything that will take out a Jeep. The frame will probably bend before a 1/4" skid. Savvy offers a break it so we can send you a new one warranty policy. The proven strength of the gts should be enough for people to trust the 6061-T6. The spring back in the aluminum also prevents deformation. As for corrosion, I like to point back to the fact that this isn't the same aluminum in your old screen door, or you pots and pans. This stuff is much stronger. If corrosion was such a problem, why would it be used for the high end rims? Those don't corrode, and they sure don't look like garbage after 4 or 5 years, they can look great for many years. If you are worried about corrosion, get some self etching primer, and a can of spray paint. That will protect it.
 
#219 ·
Well said Gerald. If people are worried about the aluminum skids, why aren't people worried about aluminum rims? People don't take time to think things through, especially when such a revolution is making a splash in magazines, and has already been thoroughly discussed by many members.
 
#221 ·
Well now... let's not get carried away here. I think there is a point when the aluminum can gain enough leverage over itself to cause stuff to deform. That makes things unstable. There is a reason why only certain things are made from aluminum (aside from cost). I don't think you would want an axle that would flex like Carbon Fiber as you go over every bump.
 
#227 ·
Well that is what I mean. I doubt there will ever be a roll cage on the market that can be properly designed to create such a balance between cost and strength that it wouldn't sell. As you said, that cage is a part of the frame. The curved design is should help provide strength. IIRC, you are an engineer, correct?

It all comes down to what can be done at a reasonable cost, not just what can be done. I bet enough money could make lumpster's dream possible, but Blaine is already creating products that are at the fringe of strength, weight, and cost. He also works things out to grow with the vehicle. A frame of al would HAVE to have the cage designed from the start to create an effective mesh of metal that would properly fulfill its duties.

I got up close and personal with that frame at the 2005 NY International Autoshow. The design of it shows what care is taken to keep a strong design.
 
#230 ·
Well that is what I mean. I doubt there will ever be a roll cage on the market that can be properly designed to create such a balance between cost and strength that it wouldn't sell. As you said, that cage is a part of the frame. The curved design is should help provide strength. IIRC, you are an engineer, correct?

It all comes down to what can be done at a reasonable cost, not just what can be done. I bet enough money could make lumpster's dream possible, but Blaine is already creating products that are at the fringe of strength, weight, and cost. He also works things out to grow with the vehicle. A frame of al would HAVE to have the cage designed from the start to create an effective mesh of metal that would properly fulfill its duties.

I got up close and personal with that frame at the 2005 NY International Autoshow. The design of it shows what care is taken to keep a strong design.
I actually did some googleing and there are already companies that make aluminum jeep tubs and frames, no prices, so I'm sure there quite a bit and custom to each job so a generic price isn't possible. I personally would rather build a buggy then modify a TJ if I was worried about the weigh enough to get an aluminum frame and body.

If you thought an aluminum roll cage was scary look up carbon fiber roll cages.
 
#236 ·
lol, way to get back on topic. I think the aluminum makes the best compromise between cost and worth. I know someone who was going to buy CF skids for his GMC Jimmy (he had no brains). I laughed at him when He said that though. I told him that it wasn't real CF like his beloved Planes, and it would just crack on the first hit.

So Gerald, is there any more info on the TT? Have we decided on a final BL size, will it replace the mounts, or go on top? We are excited to see some of this stuff.
 
#242 ·
sure you've heard of ceramic drills. Titanium Nitride (TiN) is a common ceramic coating on a HSS bit, even lower quality HF or hardware store drill bits. Titanium carbo-nitride (TiCN) is a common coating on high quality drill bits - usually for machining production stuff. there are also the uber-expensive high performance equipment that spins very high rpms, where even tool balance becomes an issue. Look up PCD (polycrystalline diamond) and CBN (cubic boron nitride). more: High Speed Drill Bits - Carbide Drill Bits
 
#243 ·
Unlimited04, I thought you are such a liar. You can't be an engineer with all of this tool knowledge. Most of those idiots just make numbers look like they are doing something :teehee: Jk. Our Off-topic talk (slightly, not that far off topic) is teaching me a lot about fab. I thought slow was a go for metal. I am somewhat used to the old school method for metal drilling though. We have a drill press that is set to turn very slowly, and that thing cuts through metal as if it was blasa wood (well, the bits that haven't been destroyed).
 
#247 ·
The amount of weight in a bumper or skid that you lose is negligible to the CG. If you changed from all steal bumpers and armor to all aluminum, you may notice a difference. But I doubt the CG would change enough to notice. You'd feel your Jeep become nimble again.
 
#250 ·
Actually, you are probably right. I think my original estimation was way off. I think a stock TJ weighs something like 3,500 lbs. If you figure that a well designed aluminum structure can weight abotu 25% less than an equally built piece (just throwing out a number there), that is like saying that we will save about 1k off of a 4k rig. So... that is more like 3,000 lbs.
 
#252 ·
there are times I wish I didn't live on the east coast...and that I made a donkey load more money than I do...damn...I'd like to be SAVVY...someday...
 
#253 ·
BAM!...........just purchased the UCF 1/4" Carbon steel Belly up! I figured that a coat of paint will keep the rust away, and that extra 40 lbs or so over the aluminum one won't change my CG enough to account for the higher expense of aluminum. Cant wait!! btw, UCF seem to be really good at sending confirmation emails and status reports...good PR!
 
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