Sport w/Max Tow - What not to change to maintain payload capacity?

[jms245]

Is it possible to put bigger tires and maybe a <=2" lift on a Gladiator Sport w/Max Tow without significantly decreasing its payload or towing capacities? I would like to put on 33" (or maybe 35") tires without compromising its capabilities. Only do light off-roading. Primary use of the vehicle is to haul stuff and to be comfortable on the highway.

If it is possible to increase the tire size, would appreciate any recommendations on specific tires that will have the necessary load and top speed ratings, decent off-road / snow traction, but comfortable and not too loud when driving with the doors and top off. Would also appreciate specific recommendations on what if any changes would need to be made to the suspension that wouldn't cause any decrease in payload or towing capacity, or highway comfort.

Thank you.

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[saintpauljeff]

+1 for responses on this topic as well

 

[ShadowsPapa]

ANYTHING you put in or on the Jeep that increases the weight carried by the springs will DECREASE payload. Period. Put a 50 pound dog in the back seat you just lost 50 pounds of payload for other stuff. Put a winch on it, you lost whatever that winch weighs from your payload. If the payload sticker on the door jamb says 1200 pounds payload, and your winch and plate and cables and all add up to 100 pounds, you now have 1100 pounds for payload.
Tires decrease towing but it's more complex to figure. Larger tires equate to changing the weight of the vehicle so it has to work harder to move the tires, wheels, whatever - plus is changes the final gear ratio - the engine has to work harder, generates more heat, that heat has to be removed. In the JT you may not get up into 8th gear so in the end it would settle out, but taking off you lose the power to get the load moving as you have increased the ratio of first gear with larger tires.
There are youtube videos, some have been posted in this forum, that explain when you lift and put on bigger tires, you decrease the towing capacity. How much depends on the total of what you do. It's not a simple calculation like payload which is weight-based.

If you are only going to do "mild off-roading" why even lift at all? It's not necessary - again, as explained in another thread where someone asked what they needed to do...... you really don't need to do anything to take these off-road even in some pretty rough areas.
Almost anything people do with these is for looks. Bigger is more macho. Lift - the higher, the more macho. Doesn't make the Jeep better other than looks, and personal feelings about it.
Lift and large tires are only for extremes. The rest is looks. Unnecessary. I bet with only better tires for traction, even if the same SIZE, I could take my overland where a lot of others here go. Unlifted.

 

[Proximo]

You are wanting a unicorn. Any and every change made to suspension and/or tires will change your payload and towing. I don't know the specifics, but you are in the correct place. This forum has an abundance of knowledge (sometimes overwhelming). Make good choices for what your primary need of the truck is

 

[Bobzdar]

Jeep chose the specific tire size to maximize towing - larger tires will probably reduce effective towing capacity by moving the engine out of the ideal rpm range and by increasing unsprung weight. As to how much, it's purely a guess, but the Rubicon with the exact same axles, cooling system etc. but 1" larger tires and front skid plate loses an effective 200lbs in towing capacity (it weighs ~400lbs more but has 600lbs lower towing capacity). Some of that is the tire size, some the tiny loss of cooling air from the addition of the skid plate. If I had to guess at the loss in towing capacity from moving to 34" tires and a 2" lift on a max tow, I'd guess around 300lbs - 250lbs for the change in effective gear ratio and increased wind resistance and 50lbs for the added weight of the tires.

 

[jms245]

Lift and bigger tires is for increased ground clearance to lessen the opportunities for high centering on a muddy trail. Never had that happen with my YJ, but did with my JKU Rubicon. The longer wheel base of the Gladiator is another step of vulnerability for that.

It's all about figuring out the right balance between competing requirements.

I think a good starting point would be to figure out with knowing the specific tire make, model, and size of the tire that comes stock with the max tow Sport, looking at its load rating, and then looking for 33" options that are similar. But I then don't know what to do, if anything, with the suspension so as not to significantly decrease the payload and towing capabilities.

Additionally, with my JKU Rubicon, I put 33" Duratracs and a Teraflex leveling kit on it, but didn't change the shocks. I dealt with some chopping in the wear of those tires that increased the tire noise. Want to be sure to put a good combo together of tire and suspension.

For towing, I'm okay with losing a few hundred pounds of capacity, but losing 1000 lbs would be too much. For payload, minimal loss is best, with a maximum in the 200-300 lbs range.

 

[PyrPatriot]

ANYTHING you put in or on the Jeep that increases the weight carried by the springs will DECREASE payload. Period. Put a 50 pound dog in the back seat you just lost 50 pounds of payload for other stuff. Put a winch on it, you lost whatever that winch weighs from your payload. If the payload sticker on the door jamb says 1200 pounds payload, and your winch and plate and cables and all add up to 100 pounds, you now have 1100 pounds for payload.
Tires decrease towing but it's more complex to figure. Larger tires equate to changing the weight of the vehicle so it has to work harder to move the tires, wheels, whatever - plus is changes the final gear ratio - the engine has to work harder, generates more heat, that heat has to be removed. In the JT you may not get up into 8th gear so in the end it would settle out, but taking off you lose the power to get the load moving as you have increased the ratio of first gear with larger tires.
There are youtube videos, some have been posted in this forum, that explain when you lift and put on bigger tires, you decrease the towing capacity. How much depends on the total of what you do. It's not a simple calculation like payload which is weight-based.

If you are only going to do "mild off-roading" why even lift at all? It's not necessary - again, as explained in another thread where someone asked what they needed to do...... you really don't need to do anything to take these off-road even in some pretty rough areas.
Almost anything people do with these is for looks. Bigger is more macho. Lift - the higher, the more macho. Doesn't make the Jeep better other than looks, and personal feelings about it.
Lift and large tires are only for extremes. The rest is looks. Unnecessary. I bet with only better tires for traction, even if the same SIZE, I could take my overland where a lot of others here go. Unlifted.

Could not have said it better myself. Jeep engineers were VERY specific in pushing the abilities of the JT. If they could have gotten the Rubicon to match the Max Tow in payload they would have. You can't have 2 bites at the apple - Rubicon offroad performance with Max Tow capability.

In reality, given the impressive (claimed) feats folks have done with their JTs, you COULD lift your JT, put on 35s, and carry 1500lbs or tow 7500lbs for a bit. HOWEVER, it will cause an indeterminable (but significant) amount of increased wear and permanent damage to your vehicle. The geometry change will cause strain on the driveshaft. The strain on the cooling system from the extra weight + towing will wear out components much faster.

Here is my personal experience with working outside of the mfg specs. I have a 2006 Honda Element EX-P, AWD. As a younger man I thought there was NO way the 675lb payload was legit. I thought it MUST mean 675lbs + 4 150lbs occupants. That my beloved toaster could haul 1275lbs and be ok. And it did. I frequently put in 1000lbs in it. It didn't have lots of weight in in constantly for a decade, but there were several heavy hauls and periods of days/weeks scattered throughout where it was loaded beyond posted capacity. I would help friends move. I would help my mother with gardening. When I moved for grad school my E had 800lbs in it for WEEKS. I would later keep hundreds of pounds of gear, fluids, jack, etc. in the bed because I was always having to fix it and didn't have a garage. What was the result after 10yrs of living this way? After the 100k mile mark I have probably spent thousands of dollars each year on repairs that should have been premature. Every 2 years I had to replace the brakes, calipers, and lines. My brake and power steering fluid were often low for no reason I could see. I started keeping bottles in the car. Despite all the money put into fixing/upkeep one day I came to find a giant pool of 4 vehicle fluids under my car. The transmission fluid reservoir was empty. My power steering and brake fluid were low. The 4th was gear oil. I managed to top off enough fluid to drive it to a Honda dealer who at that point wanted $2k just to figure out what was wrong with it. A mechanic my family recommended (low key, worked in a tiny shop and was more junkyard than mechanic) ended up replacing brakes, calipers, brake line, rack and pinion, axle rods, joints, bearings, etc. I still need to replace all 4 engine mounts, the transmission side mount is torn. The alternator was also recently replaced and now the starter has finally died (normal for the mileage). So, I had a great run in abusing my small SUV. But it cost me. And I didn't know any better. Now, I love that little toaster. It has significant sentimental value to me so I'm looking at another $3k to keep it running for a few more years. But all the thousands I spent on brakes, steering, suspension, etc each year could have been avoided if I had not exceeded the specifications. By how much? Hard to tell. The JT is build of sturdier stuff, but then again Hondas are known for great quality and durability as well.

I won't be changing ANYTHING on my JT until it's warranty is over. For now if I need to offroad I have a dedicated set of wheels and M/T tires in the same size as OEM. It's worked out just fine using those for my outings on the muddy rutted abandoned coal roads in the mountains of Eastern KY. After the warranty expires I'll be doing daily driving on OEM sized tires and since folks are reporting favorable results with 35s without modifications I'll save those for offroading trips, as even 100mi here and there with the changed geometry and weight, even offroading, isn't going to strain the mechanics as much as 20k mi of daily driving on the larger tires.

 

[PyrPatriot]

Lift and bigger tires is for increased ground clearance to lessen the opportunities for high centering on a muddy trail. Never had that happen with my YJ, but did with my JKU Rubicon. The longer wheel base of the Gladiator is another step of vulnerability for that.

If you have any experience with the Appalacian mountains of Western VA, such as Pine Mountain or Black Mountain, I went up and down that area on 255/75/17 Falken MTs (which are almost the same size as OEM, maybe 1/2" bigger diameter) with no problems. No issues on the rutted coal roads after a rain this past Christmas.

It's all about figuring out the right balance between competing requirements.

I think a good starting point would be to figure out with knowing the specific tire make, model, and size of the tire that comes stock with the max tow Sport, looking at its load rating, and then looking for 33" options that are similar. But I then don't know what to do, if anything, with the suspension so as not to significantly decrease the payload and towing capabilities.

The OEM tires for the Max Tow are Bridgestone Dueler A/T HS-3. They don't have a load rating like C or E. They have a work rating of 112T, which means about 2500lbs per tire. That was about the same as the Load C Falkens I had on. Even not airing down I did fine on the muddy mountain trails. The Max Tow rear springs are very specific to that option. Their part numbers are different from the Rubicon and Sport. They are the reason the Rubicon only has an 1100-1200lb payload whereas the Max Tows have 1500-1700. Change out those springs, well I asked the folks/engineers at Jeep and they said they couldn't test out the ratings of swapping spring parts and have no answer as to just how MUCH payload/towing is decreased if using anything other than the oem parts in the Max Tow.

Additionally, with my JKU Rubicon, I put 33" Duratracs and a Teraflex leveling kit on it, but didn't change the shocks. I dealt with some chopping in the wear of those tires that increased the tire noise. Want to be sure to put a good combo together of tire and suspension.

For towing, I'm okay with losing a few hundred pounds of capacity, but losing 1000 lbs would be too much. For payload, minimal loss is best, with a maximum in the 200-300 lbs range.

Based on my research into the subject (sources provided in the thread I made on the subject) you'll lose 20% towing for every 1" in lift and tire combination, at least 1500-2000lbs with 2" bigger tires and a Mopar 2" lift. Now, folks who have done said changes reported their rigs towed/carried just fine, albeit feeling sluggish sometimes. Again, CAN something be done and what is the cost you pay long-term is the thing you gamble on. The JT is a new vehicle, only real-world experience will show. The guy saying he drove through CA and over am mountain at max tow capacity and 800lbs over max payload the whole several thousand mile trip, with no noticeable wear (based on some fluid eyeball test) may be right, or he may not be knowing what he's talking about. The amount of $ you want to risk on the benefit you seek is the ultimate decider. For me, I have to reason that FCA could have sold WAY more of these and under a 1ton truck label if they could safely and reliably long-term perform like that. But FCA didnt.

Regarding payload, you'll probably go down to Rubicon payload numbers and towing if you put Rubicon parts on your Sport. The towing may be a little more than the JTR because of the lighter weight from missing the lockers and other off-roading features.

So yes, I chose not to pursue the same idea you are having because I concluded I'd lose 350lbs of payload and 1500lbs of towing if I did that, and I didn't pay for a Max Tow or even get a truck in the first place to lose that capacity for offroading. If offroad performance was more important to me than payload or towing, I would have gotten a JLU

 

[TheSolarWizard]

Different tires won’t change payload

 

[PyrPatriot]

Different tires won’t change payload

Oh but they can. If you go big enough, you change the geometry. The control arms are raised, the springs are not in their native/intended state of being under load. The changes will probably be subtle given any tire size increase that doesn't warrant a lift is fairly small, but it does lower the payload because larger tires lift the vehicle, which means the springs are now stretched instead of being compressed, and the change in how they compress under load changes how they handle the load, thus payload will be affected.

Of course if someone like @ShadowsPapa wants to correct me I won't argue.

 

[TheSolarWizard]

Oh but they can. If you go big enough, you change the geometry. The control arms are raised, the springs are not in their native/intended state of being under load. The changes will probably be subtle given any tire size increase that doesn't warrant a lift is fairly small, but it does lower the payload because larger tires lift the vehicle, which means the springs are now stretched instead of being compressed, and the change in how they compress under load changes how they handle the load, thus payload will be affected.

Of course if someone like @ShadowsPapa wants to correct me I won't argue.

Springs are stretched?! WOW now I’ve heard everything

 

[PyrPatriot]

Springs are stretched?! WOW now I’ve heard everything

Springs, as a concept, CAN be stretched.

Would uncompressed be a better term? Less compressed than with OEM height?

 

[ShadowsPapa]

Different tires won’t change payload

There's a youtube video out there where a truck guy is explaining all of that -

Of course - how many here swap tires and don't do a lift? So for most Jeep people swapping tires will change a lot because it means they also lifted.

 

[ShadowsPapa]

Springs are stretched?! WOW now I’ve heard everything

You should see what some AMC people do to drop their cars down - cut coils, heat the spring and compress it, And Eagle people do stupid things to get a bit of lift.
But that's a different concept, different topic.

 

[JRobes]

Oh but they can. If you go big enough, you change the geometry. The control arms are raised, the springs are not in their native/intended state of being under load. The changes will probably be subtle given any tire size increase that doesn't warrant a lift is fairly small, but it does lower the payload because larger tires lift the vehicle, which means the springs are now stretched instead of being compressed, and the change in how they compress under load changes how they handle the load, thus payload will be affected

Putting larger tires on the vehicle does NOT change anything with the geometry/angles of the suspension (unless you consider the spare's increased weight decreasing the payload). Wheels/tires are not supported by the vehicle suspension, and thus changing their height/weight doesn't cause the vehicle to sag any more or less.

I do agree that larger/heavier tires does reduce your towing capacity though as they need extra oomph/stopping power to get moving or stopped.

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