TJ Diet: How to Keep Your TJ Light

SSTJ

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This thread got me thinking that it'd be nice (especially for those of us with 4-cylinder engines) to make a list of ways to keep the TJ light. @Chris, if you agree, we can make this a resource.

I'll make a start below, and will update as ideas come in through others' posts. Also, if you know an estimate of how much weight would be lost with any items below, let me know and I'll update.

Deletions:​

  • Back Seat
  • Passenger Seat
  • Spare Tire (if you dare)

Replacements:​

  • Hard Top ==> Soft Top
  • Full Doors ==> Half Doors
  • Matching Spare ==> Pizza-Cutter Spare on Light Wheel
  • Factory Tranny Skid ==> Aluminum Option (e.g. Savvy)
  • Factory Gas Tank Skid ==> Aluminum Option (e.g. Savvy)
    • Note: Savvy gas skid is 4 pounds heavier than 03-06 factory skid. 97-02 factory skid is lighter.
  • Steel Corner Guards ==> Aluminum Option (e.g. Genright)
    • Aluminum full corner guards saves 49lbs over steel?
  • Steel Fenders ==> MCE or Aluminum Option (e.g. Genright)
    • Front fenders are 9.3lbs each, versus steel at 21.75lbs each?
    • Rear fender pair is 30lbs lighter than the steel pair?
  • Wheel Choice: doubly important because it is not only weight, but rotational mass, too.
  • Tire Choice: doubly important because it is not only weight, but rotational mass, too.
    • Example: Chris's 35" Nitto Trail Grapplers weigh 82lbs each, versus the 35" Goodyear MT/Rs at 62lbs?
  • Control Arms: Not worth worrying about.
  • Winch Cable ==> Synthetic Line

Temptations / Compromises:​

  • Body armor.
  • Sound deadening material.
  • Mass-backed aftermarket carpet.
  • Sand bags in the back, to make shocks feel softer (yes really).
  • Aftermarket off-road bumpers. (To keep things light, see this thread.)
  • Drive-train wise, your biggest weight adders will be moving from a Dana 30/35 combination to Dana 44s front and rear. And, adding a 241 transfer case. This is why you see a 300 lb difference between the sport and Rubicon models. (from @Irun)

References:​

  • Wikipedia Curb Weight: 3,092–3,857 lb (1,403–1,750 kg)
  • FourWheelTrends, 05–06: 3,460 lbs (curb) and 4,450 lbs (gross weight)

Forum Member Reports:​

 
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Anyone know the factory weight of each model? SE, Sport, Sahara, Rubicon? Unless it varied year by year ...
 
No top.
No doors.
No spare.

Yet his Jeep is still overweight.

20210527_211056.jpg
 
Few more thoughts. Tire and wheel choice are doubly important because that is not only weight, but rotational mass, too. Carpet is another thing you could remove for a marginal weight decrease, but you'd be compromising heat insulation. I'm skeptical about how much - if any - weight is saved switching from the factory transfer case skid to Savvy under armor. We don't often talk about MCE fenders in regard of weight reduction, but after cutting that section of metal fender off for the install, that has to be some weight loss.
 
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Its funny cause when you first get into this you want a Jeep that looks a certain way. Or items you think are going to improve offroad performance.

Its not until some time later you discover that all those steel bumpers, rock guards and tire carriers. Are going to slow you down. Big time.

Luckily i discovered this before buying a ton of heavy crap. I didn't really need.

We need a "Things to do and not do. When you buy your first Jeep." ;)
 
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Its funny cause when you first get into this you want a Jeep that looks a certain way. Or items you think are going to improve offroad performance.

Its not until some time later you discover that all those steel bumpers, rock guards and tire carriers. Are going to slow you down. Big time.

Luckily i discovered this before buying a ton of heavy crap. I didn't really need.

We need a "Things to do and not do. When you buy your first Jeep." ;)
I really like my LJ2 with no spare tire carrier or spare on the back vs LJ1 with aftermarket swing out and tire.
 
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Its funny cause when you first get into this you want a Jeep that looks a certain way

Its not until some time later you discover that all those steel bumpers, rock guards and tire carriers. Are going to slow you down. Big time.
I can relate to both of those points. I bought my first front bumper based purely on shape and appearance. I sold that one a while back and now have an 11 lb one in its place. I was advised not to buy a huge steel tire carrier bumper a long time ago. Of course, since I knew better, I bought it anyways :rolleyes:. Just sold it a couple of weeks ago, and dropped over 100 lbs. I have a habit of learning things the hard way...

Since removing that tire carrier bumper and the spare (~150 lbs) the difference is very noticeable while driving. In every modification I make, weight is now always a consideration.
 
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The Savvy gas tank skid is 4 pounds heavier than the 03-06 factory skid plate. If your goal is weight reduction, you should find a 97-02 factory skid plate.

Wow, I would not have guessed that. Do you know the weight difference of the 97–02 factory gas skid? And do you know if it will work/fit on an 03–06?
 
Few more thoughts. Tire and wheel choice are doubly important because that is not only weight, but rotational mass, too. Carpet is another thing you could remove for a marginal weight decrease, but you'd be compromising heat insulation. I'm skeptical about how much - if any - weight is saved switching from the factory transfer case skid to Savvy under armor. We don't often talk about MCE fenders in regard of weight reduction, but after cutting that section of metal fender off for the install, that has to be some weight loss.

Thanks, that's a good point about wheel choice. Also MCE fenders. Will update the original post.

And yes, I need to call Savvy and get some numbers to back that up.
 
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Wow, I would not have guessed that. Do you know the weight difference of the 97–02 factory gas skid? And do you know if it will work/fit on an 03–06?
I believe it does, however that comes at a cost of being weaker. Some places it makes sense to add a little weight for the protection you want. Shave it elsewhere, like the transfer case skid.
 
I believe it does, however that comes at a cost of being weaker. Some places it makes sense to add a little weight for the protection you want. Shave it elsewhere, like the transfer case skid.

Yea, good call. Still, helpful info for the purposes of this thread. I have a 97 2.5L that rarely goes off road, so I'm glad to know I already have the lightest option.
 
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This company is based out of Kelowna, BC. If a guy was rich he could buy one of their aluminum tubs:LOL: For those of you in the US of "eh?" there's the dollar advantage;);););)


https://www.hardbody4x4.com/jeep.html
They are not lighter. They are likely a fair bit heavier than the steel equivalent due to how it is constructed. Basic rule of thumb comparing steel to aluminum is aluminum is 1/3 the weight of steel. The cabs are made from .156 thick 5052 which is almost exactly 3 times as thick as the 18g .050 used most places on the TJ to form the body. That means they would be about the same weight if the AL was formed and assembled using the same methodology of spot welds instead of the continuous aluminum beads used by Aqualu.
 
I've been obsessed with the weight topic for a while now. When building TJs my experience has been that getting one well built under 4200 lbs is almost impossible, unless you strip them down. Counting the weight of every modification is important, so using aluminum to the maximum extent possible is critical. For armor, the only place I can think to run steel would be on the rockers. This is the beauty of something like Savvy's rocker armor. It uses an aluminum rocker panel, combined with steel sliders. The steel slider allows you to pivot over obstacles better than with aluminum.

Drive-train wise, your biggest weight adders will be moving from a Dana 30/35 combination to Dana 44s front and rear. And, adding a 241 transfer case. This is why you see a 300 lb difference between the sport and Rubicon models. Wheel and tire choices, along with heavy bumpers are other things most don't think about. In the end keeping weight down can be done. It becomes a bit of a religion and is, in the end, very expensive. However, it's worth it. Overall, a lighter and well built rig will perform very well on and off-road. Braking, accelerating, and climbing will all improve.