Max fuel capacity

[ShadowsPapa]

Ain't nobody got time for that! I know nobody driving a dealership rental is worrying about the break-in procedure.

That's because the raw gears sold in bulk to 4x4 shops are quite different than what Dana installs for shipment to Jeep's assembly plant.
The gears in a car or truck sold assembled are already lapped, half the work is done. They'd done most of the break-in already.
The gears for aftermarket are much more raw. They've been made, and that's about it.
Cost is one reason, but the other is - what car buyer is ever going to limit the speed to 50, stop after 15 or 20 minutes or whatever THAT gear vendor says and then sit for 10, 15 or 20 minutes - again, whatever THAT gear vendor says (and it varies!)
Ain't no one gonna buy a car or truck and go through that BS.
They come from the factory mostly ready to go. A final burnishing is all that's needed.
Imagine a company selling a car or truck that isn't ready to go.
And frankly, I'd bet that 99% of all cars and trucks sold and driven off the lot get driven exactly as the buyer drove their last one, or how they intend to drive it next month.
Most may adhere to the "don't tow yet" bit but really - you take a new one on a test drive, to baby it sort of defeats the purpose, and a rental? Please - they get driven like they were stolen.

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[Geoarch]

The reason? Installers like these 4x4 shops are using new raw gears. They are as manufactured for BULK SALE.
The factory making these differentials are using gears that are lapped in.
There's no need to follow the 4x4 shop's break in - half the work is already done.
That also negates any need for changing differential lube after 500 miles on a new truck.

Take a new gear set from the shelf in a shop and look at them, feel them, rub fingers over them, look at them with a magnifying glass........ a lot different surface than what you get in your new truck from the factory.

Think of it - are you going to have to do all of that work and effort and change lube 500 miles later on a new truck? Would you even do it? Naw, no one ever would. The companies sell cars and trucks to teens, executives (male or female) soccer moms, farmers, you name it - and none of them are going to go through all of that.
From way back, hypoid gears have been worked differently than those sold as sets going into trucks or Jeeps where the owner is a different sort, wants to get gears at a lower cost and is willing to do extra work for something they asked to be put in as an upgrade.

I'll toss another variable at ya - while some shops recommend brands of lube, others do not, or they will contradict what shop A said. If I had to use a specific brand, naw, that's their favorite, that's all. And some simply choose one to make sure that if there's a come-back, it wasn't a cheap no-name walmart shelf brand. I'll use a high quality lube that's got a high pressure rating, not one that people choose because a shop, or buddy or the internet says so.
And the break-in processes even vary from gear vendor and shop to the next guy. I've compared some of the different "you must do this" lists and frankly, some of them vary quite a bit. Some basics are there but the numbers and instructions actually vary a bit.
Anyway, it's for sure you need to take extra care with newly installed after-market gears. They haven't been lapped, they haven't been burnished, the surface is raw. Very different animal than what Dana put in in their plant before shipping to Jeep's Ohio facilities.

For either - I would avoid towing. I would avoid a "heavy load" (I'd not drive from the dealership right to Menards (across the street from each other) and load up with 1200 pounds of bricks and then hit I80 and zip across the north side at 75 mph.

On a new gear set - an after-market replacement, one reason I would personally want to pull the cover off, besides making sure they did a good job and there aren't chunks in there) would be to inspect the pattern to make sure it was centered and the correct shape on both sides of the ring gear teeth. (because of the things I've seen, I guess I trust but verify)

I did inspect the gears when I changed the oil at 500.

Thanks for that. I had no idea that the factory lapped gears, but makes sense.

 

[JET_83]

The manual says stay (p.158) below 55 for the first 60 miles:

So, how fast do you drive for the first 60 miles - 10 mph, 20, 30, 40, 50 or? Or does it say for the first 60 miles under 55, and after that stay under 140?
So we all should get bitchen gas mileage for the first 300 miles or 60 miles whatever it's saying, then it's down to 16 mph! I haven't received by JTR yet, so I have some time to unravel the poorly written sentences on page 158 (and elsewhere). Geez.

Let's make it more complicated. In my TRDPro, I installed 4.56 gears from the OEM 4.30s. East Coast Gear Supply, and indeed my installer in New Mexico said:

New gear sets MUST be broken in correctly to prevent damage. Not following proper break-in procedures will lead to overloading and overheating the ring and pinion as well as breaking down and ruining the gear oil. Not following proper break-in procedures can be determined during inspection and will void the warranty.

Please follow the below guidelines to ensure a proper break-in and long life of your gears.
• Only use high quality gear oils. ECGS recommends Lucas non-synthetic 85W-140
• On initial run, drive lightly for 15 to 20 minutes then stop to allow differential to cool completely for 20 to 25 minutes.
• Avoid towing and heavy acceleration, as well as vary speeds every 5 to 10 minutes while driving on highways.
• Drive conservatively and do not drive more than 50 miles at a time without allowing a cool cycle during the first 500 miles following installation.
• After completing initial break-in, change gear oil at 500 miles. Small metal particles are normal and gear oil will typically be black. Excessive metal in gear oil should be reviewed by a competent differential mechanic to ensure safety of internal parts.

This would be for the rear gears. The front is used much less often, and generally at lower speeds, so I assume you can ignore and change the oil at some future date.

So, our Gladiators come with new gears (3.73 or 4.10). So why don't we have to follow the gear break-in you would with a new gear set. Inquiring minds want to know... This is how I'm spending my 4th?

Yeah I drove that speed for the first 300 miles, since that’s what’s desirable. I drove 55 MPH for 400 miles never exceeding that actually until I went over 400 miles. I averaged about 29.5 MPG

 

[Geoarch]

Yeah I drove that speed for the first 300 miles, since that’s what’s desirable

Ok thanks. Now I just need the Jeep.

 

[Gvsukids]

Yeah I drove that speed for the first 300 miles, since that’s what’s desirable. I drove 55 MPH for 400 miles never exceeding that actually until I went over 400 miles. I averaged about 29.5 MPG

There's also the brief throttle acceleration.

 

[JET_83]

There's also the brief throttle acceleration.

I know, I did that too

 

[skindata]

Yesterday on the way home from work, I ran it as low as I basically could to see how much I could get in it. It went from 10 miles of range to LOW for about 5 minutes before I pulled into Speedway and filled it up before it auto shut off. I got 19.848 gallons.

 

[313IFD]

Next time you fill-up, pull the nozzle part way out and keep filling, as slow as possible. Wait a couple seconds each time the pump kicks off and resume filling. Sounds crazy, but if you are slow and very careful to not overfill, I bet you can get at least 2 addtional gallons in your tank. I've tested my theory at dozens of fill-ups at different gas stations in 6 different states, removing all blame on the gas or the pump. I'm able to add 2 to 3+ gallons of gas after the pump kicks off the 1st time. I've topped 22 gal after the burble has kicked the pump off under 20 gallons and range below 20 miles. I hear that this practice is bad for the evaporator or something so I've done it only in the middle of a long trek, knowing I'm stopping again for gas. Can anyone confirm if there's a legit risk to my baby or is it an environmentalists' story for preventing spillage?

 

[ShadowsPapa]

Next time you fill-up, pull the nozzle part way out and keep filling, as slow as possible. Wait a couple seconds each time the pump kicks off and resume filling.

And your dealer shop will love you - flooding the canister...............
There is a very real risk trying to prove how much you can get into that tank. Read back a year or two.
It's a real risk. People have had to have things replaced after trying to prove others wrong.
Topping off for over 22 gallons is really risky, and really not smart, depending on circumstances. Gasoline expands in heat. If you fill it and top off and get 22 in it and the outside temperature is upper 80s or better, when the fuel expands it will have to go somewhere.
We aren't talking "spills" - we're talking flooded equipment.

 

[313IFD]

And your dealer shop will love you - flooding the canister...............
There is a very real risk trying to prove how much you can get into that tank. Read back a year or two.
It's a real risk. People have had to have things replaced after trying to prove others wrong.
Topping off for over 22 gallons is really risky, and really not smart, depending on circumstances. Gasoline expands in heat. If you fill it and top off and get 22 in it and the outside temperature is upper 80s or better, when the fuel expands it will have to go somewhere.
We aren't talking "spills" - we're talking flooded equipment.

I appreciate the insight and will research deeper into the ills of topping off. I've done this in the middle of long trips, assuming my jeep would drink the 1st gallon in the next 20 miles or < 20 min of the trip and have 2 gallons gone in about 1/2 hr @ 70 mph. Expansion shouldn't be a concern in that short of time and while she's drinking it down. I am concerned if topping overfills/overflows something I can't see.

 

[Mr._Bill]

Topping off fills up the Evap Canister once the tank is full. Eventually, it will fail. If you are cutting it that close between filling stops, you should probably be carrying a five gallon can in back instead of trying to stuff extra in the tank. I fill using the slowest setting, and only squeeze in about a third of a gallon more. Around town, I fill when I get down to a half tank. When traveling, I try to avoid going below a quarter tank.

 

[Hootbro]

Next time you fill-up, pull the nozzle part way out and keep filling, as slow as possible. Wait a couple seconds each time the pump kicks off and resume filling. Sounds crazy, but if you are slow and very careful to not overfill, I bet you can get at least 2 addtional gallons in your tank. I've tested my theory at dozens of fill-ups at different gas stations in 6 different states, removing all blame on the gas or the pump. I'm able to add 2 to 3+ gallons of gas after the pump kicks off the 1st time. I've topped 22 gal after the burble has kicked the pump off under 20 gallons and range below 20 miles. I hear that this practice is bad for the evaporator or something so I've done it only in the middle of a long trek, knowing I'm stopping again for gas. Can anyone confirm if there's a legit risk to my baby or is it an environmentalists' story for preventing spillage?

Your EVAP cannister will suffer premature failure. Just because the damage is not immediately evident, does not make it a good practice. When it does fail, a good shop will know it and deny you warranty as they should.

 

[Marlinvx]

All y'all waiting until empty to fill up aren't preppers and must not remember 9/11. I fill up at halfway mark in town, 1/4 tank when travelling. I have trained my kids and wife to do the same. I remember waiting in line to get gas on 9/11.

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