TJ Diet: How to Keep Your TJ Light

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.
Now you fully get how impressive the Savvy race TJ Unlimited was that weighed right at 4200 in full race trim excluding fuel and passengers.
 
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.
@mrblaine My apologies. Thanks for clearing that up.
 
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.

Given that it is 3x as thick, is it stiff enough that it doesn't need as much armor and saves weight vs a fully-armored steel tub?
 

References:​

  • Wikipedia Curb Weight: 3,092–3,857 lb (1,403–1,750 kg)

I am doing ok then. I weighed my TJ last year at a state certified scale with a full tank of gas and my toolbox with all my gear and came in at 4,080 lbs. Since then, I've lost the tool box (could probably weigh it tonight) and 40lbs of steel fenders. I should be somewhere a little over 4k lbs :D
 
I am doing ok then. I weighed my TJ last year at a state certified scale with a full tank of gas and my toolbox with all my gear and came in at 4,080 lbs. Since then, I've lost the tool box (could probably weigh it tonight) and 40lbs of steel fenders. I should be somewhere a little over 4k lbs :D
That’s the reason I wanted to get rid of all my steel corners, rear fenders and steel front fenders, steel engine skid are all being replaced with Aluminum. Also plan to get an Aluminum front bumper soon as well. My pig weighed in at almost 4900# with a full tank and all my gear and tools in it. I know my larger axles, tires, Atlas 4 speed and beadlocks certianly don’t help matters. The new smaller tires should help a bit also. Can’t wait to get it back on the scales. If my calculations are correct I should have lost about 175# total. I could probably ditch about 75 - 100# worth of spare parts and tools and gear I carry that is not necessary as well. I’ve always been one of those gotta be prepared for any and everything kinda guys. Rather than just keeping the bare minimum of gear needed. But hey I could survive comfortably for at least a week if I had to out there 😂
 
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This thread has been sleepy for a while, and I'm sure it can be improved. Anyone have any suggestions or additions for the original post?
 
This thread has been sleepy for a while, and I'm sure it can be improved. Anyone have any suggestions or additions for the original post?

I have been looking at it like, moving the weight away from and then to where it matters more. For the front bumper, I went to a Savvy with a winch from the Yuge bumper without a winch that was on it. Not sure if I saved weight but I now has a winch.
 
I have been looking at it like, moving the weight away from and then to where it matters more. For the front bumper, I went to a Savvy with a winch from the Yuge bumper without a winch that was on it. Not sure if I saved weight but I now has a winch.

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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.

Wow, never knew of the 300 lb penalty of Rubicon axles and T/C, surprising.
 
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Bump. I'm sure there's more knowledge on this forum that could be added to the original post.
 
Every little bit helps. I added it.

Soft shackles vs d-rings, aluminum safety thimbles vs hooks, minimalist recovery gear. It all adds up.

I agree that every bit helps. You can tell a real difference. Right now I have MCE Fenders. Aesthetically I’d like to go to GR Aluminum, but they’re $1500 and I’d pay a weight penalty. It’s not much, but it is something.
 
I dont know the weight of it all but the compressor, hoses, condenser, drier, have got to have some weight. Maybe 50-100lbs? Might be worth it for someone who is serious about weight.
 
For lighter body armor like corners, has anyone tired laminating composites directly to the factory steel?

Aramid or carbon cloth and epoxy isn't terribly expensive. The existing part is the mold. And any damage repair is a simple grind-and-relaminate affair.
 
I dont know the weight of it all but the compressor, hoses, condenser, drier, have got to have some weight. Maybe 50-100lbs? Might be worth it for someone who is serious about weight.

I can tell when my back seat is in or out, or I have half/trail doors on - so definitely applies for some of us weight weenies. The big jump is when I change all those things at once, it's very noticeable.
 
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