Build Recommendations!

[Rockcrawlindude]

I don’t see the problem with a 285/75-18 spare for a truck that has 37s. It’ll fit in the stock spare tire area and less than 6% smaller than a 37

 

[hothands089]

I don’t see the problem with a 285/75-18 spare for a truck that has 37s. It’ll fit in the stock spare tire area and less than 6% smaller than a 37

So carrying a 34.8” for a spare would work with 37s? I’m curious what any downsides could be.

 

[Rockcrawlindude]

So carrying a 34.8” for a spare would work with 37s? I’m curious what any downsides could be.

A 37 is more like a 35.5” in most cases. I don’t see any downsides.

 

[NHOverland]

So carrying a 34.8” for a spare would work with 37s? I’m curious what any downsides could be.

Tire wear, as long as the axle is not locked and you only go short distance. If it is locked the issue becomes the circumference difference in the two tires and can cause many more issues.

 

[Rockcrawlindude]

Tire wear, as long as the axle is not locked and you only go short distance. If it is locked the issue becomes the circumference difference in the two tires and can cause many more issues.

It’ll be fine. Won’t hurt anything. Lockers don’t care what size tires are on either side.

 

[NHOverland]

It’ll be fine. Won’t hurt anything. Lockers don’t care what size tires are on either side.

Roger that

 

[hothands089]

Got it. Definitely something to consider then!

 

[Rockcrawlindude]

It’ll be fine. Won’t hurt anything. Lockers don’t care what size tires are on either side.

Roger that

Let me amend this to say because you said locker i assumed it’s a power wagon and it has an e-locker. E locker once locked wouldn’t care one bit. And open it would be totally fine so fine either way. When locked, It may try to push/steer you a little bit to one side, but wouldn’t hurt anything

A limited slip would build up a little heat, but remember we’re talking a 4-5% difference in tire size. I wouldn’t expect significant issues in the ranges you’d expect to drive on a spare. Nothing a fluid change wouldn’t fix later if you had to drive a long way

A ratcheting locker like a Detroit, lunchbox etc would probably be pissed off and let you know.

 

[AH64ID]

Since the specs were east to find…

A Toyo AT/III in 285/75R18 rolls at 33.7”, and in 37x12.5R18 it rolls at 35.4”. That’s only a 5% smaller tire, and would be fine for short term use as a spare tire.

@Rockcrawlerdude isn't the rear e-locker in the PW a helical gear LSD when not locked?

 

[Rockcrawlindude]

Since the specs were east to find…

A Toyo AT/III in 285/75R18 rolls at 33.7”, and in 37x12.5R18 it rolls at 35.4”. That’s only a 5% smaller tire, and would be fine for short term use as a spare tire.

@Rockcrawlerdude isn't the rear e-locker in the PW a helical gear LSD when not locked?

Helical would be totally fine but the normal
2500 have clutch style which could see heat issues if you had to drive more than 50 miles or so I’d guess. But that’s still just a fluid change at most, likely not even an issue.

But you could put the spare in the front.

I’d be surprised if the factory spare is all the way full-size and not around an inch shorter. I have a factory spare on my truck running 285/75-18. I also carry a plug kit and compressor.

 

[Rockcrawlindude]

Or you could fix the tire. Obviously cut sidewalls etc can happen.

But It’s so easy a 4 year old can do it.

 

[el_barto]

Spare tire storage I understand.

I would not worry about gearing with 37s. PW comes standard with 4.10s so with 37s your effectively running 3.73 rear end which IMO is more then sufficient. I have 37s on mine with 3.73 gears and hardly noticed a difference, granted its a diesel but sharing my experience. I also live at 7k feet.

Cummins is a different story than gas. A) the Cummins diesel have so much more torque than the gas Hemi. b) they do not suffer from power loss at altitude that a naturally aspirated engine does. At 5000ft asl it’s approximately 15% loss in power.

My Power Wagon, with 35s, gets up i70 without trouble, but I’m certainly not willing to say it’s fast(I have driven fast, high power turbo cars up it and it’s a different experience). It often needs to be in a lower gear(4th, 5th) to maintain 70mph going up i70.

It’s not just the diameter but also the added rotational weight, that people feel when upsizing

 

[el_barto]

Helical would be totally fine but the normal
2500 have clutch style which could see heat issues if you had to drive more than 50 miles or so I’d guess. But that’s still just a fluid change at most, likely not even an issue.

But you could put the spare in the front.

I’d be surprised if the factory spare is all the way full-size and not around an inch shorter. I have a factory spare on my truck running 285/75-18. I also carry a plug kit and compressor.

Factory spare is a full size 285/70/17 duratrac on power wagons. Wheel is steel but tire is matching.

Personally, I’m pro-matching diameter spare. Can I limp off a trail and get home with an undersized spare? Yes. But if I’m in the middle of BFN hundreds of miles from the nearest city where a replacement tire is in stock (maybe…35s and 37s are sometimes special order, especially if it’s a bit of a less common tire)…i think the full size spare starts to have more value.

I disagree, helical lsd want matching diameters. AWD with Torsen center diff come with full diameter spare tires. It’s probably ok to have mismatch for short distances, but I wouldn’t want to put more than 50 miles on mismatched diameter.

 

[AH64ID]

Or you could fix the tire. Obviously cut sidewalls etc can happen.

But It’s so easy a 4 year old can do it.

View attachment 48766View attachment 48767

Fixed many a tire with a safety seal, most of which weren’t mine

 

[Rockcrawlindude]

Factory spare is a full size 285/70/17 duratrac on power wagons. Wheel is steel but tire is matching.

Personally, I’m pro-matching diameter spare. Can I limp off a trail and get home with an undersized spare? Yes. But if I’m in the middle of BFN hundreds of miles from the nearest city where a replacement tire is in stock (maybe…35s and 37s are sometimes special order, especially if it’s a bit of a less common tire)…i think the full size spare starts to have more value.

I disagree, helical lsd want matching diameters. AWD with Torsen center diff come with full diameter spare tires. It’s probably ok to have mismatch for short distances, but I wouldn’t want to put more than 50 miles on mismatched diameter.

Fair to disagree. it’s not an exact science and being on a spare tire for me is not OK as I’m sure it is the same with you. Something to fix immediately asap.

50/50 is the spare rule anyway. 50 miles max / 50 mph max

 

[UglyViking]

Ah, the conversation of the full size spare. Always a fun discussion. End of the day, there is no perfect solution, just trade offs. For me personally, I carry a full size spare, and a tire repair kit. It's not worth the risk for me getting stuck somewhere trying to find a matching replacement tire. My time is more valuable than the hassle and cost of carrying a 37" spare. Even for highway only travel, if I'm doing a large multi-day drive, the spare is good insurance.

 

[tchur1]

Cummins is a different story than gas. A) the Cummins diesel have so much more torque than the gas Hemi. b) they do not suffer from power loss at altitude that a naturally aspirated engine does. At 5000ft asl it’s approximately 15% loss in power.

My Power Wagon, with 35s, gets up i70 without trouble, but I’m certainly not willing to say it’s fast(I have driven fast, high power turbo cars up it and it’s a different experience). It often needs to be in a lower gear(4th, 5th) to maintain 70mph going up i70.

It’s not just the diameter but also the added rotational weight, that people feel when upsizing

Yup totally agree it’s an apples to oranges comp but figured anecdotal feedback can’t hurt. FWIW my brother has a 22 PW on 37s and lives right down the street here in Tahoe. Truck has no issues moving along efficiently. It’s not a sports car but none of these trucks are. Gearing isn’t the reason I wouldnt move to a 37.

 

[jadmt]

Welcome. Look forward to seeing your truck adventure.

Thanks for the mention @tchur1

My recommendations:
Caps : are extremely useful.

Compressors : are extremely useful.

Wheels : as long as they’re a reputable brand and in the correct size/offset/weight rating they’re good. Only a few actual places making wheels many of them come from the same place i bet. Aev wheels have a “proprietary offset” they actually fit really well. But, cjc sells methods with the perfect offset too. Plenty of wheel choices but those two allow the most tire with the least trimming.

Suspension : enjoy the truck as-is for a while. Figure out what you like and don’t like before you go jacking with it. It may be fine as it is.

Airbags : pull the trailer first and see what your squat is looking like. You may want to look into an airbag and cradle set up so you keep all your articulation and have some extra load capacity when needed

AEV publishes their offset and backspacing.
Saltas

TECH SPECS:​

Size: 17" x 8.5"
Weight: 33 lbs
Bolt Pattern: 8x6.5
Offset: +27mm
Approximate Backspacing: 5.8"
Coatings: Paint, Primer

Katla

TECH SPECS:​

Application: 2003+ Ram 2500/3500
Weight: 36 lbs
Bolt Pattern: 8x6.5
Offset: -15.6 mm (17x10), +27 mm (17x8.5)
Backspacing: 4.8" (17x10), 5.8" (17x8.5)
Coatings: Clear Coat, Paint, Primer
Load Rating: 4100 lbs.

 

[Rockcrawlindude]

AEV publishes their offset and backspacing.
Saltas

TECH SPECS:​

Size: 17" x 8.5"
Weight: 33 lbs
Bolt Pattern: 8x6.5
Offset: +27mm
Approximate Backspacing: 5.8"
Coatings: Paint, Primer

Katla

TECH SPECS:​

Application: 2003+ Ram 2500/3500
Weight: 36 lbs
Bolt Pattern: 8x6.5
Offset: -15.6 mm (17x10), +27 mm (17x8.5)
Backspacing: 4.8" (17x10), 5.8" (17x8.5)
Coatings: Clear Coat, Paint, Primer
Load Rating: 4100 lbs.

Yes. I believe every wheel manufacturer publishes their wheel specs.

I’m not familiar with another wheel that has the exact same offset as the AEV wheels.

 

[UglyViking]

I didn't realize that the Salta wheels are 3lbs lighter per wheel than the Katla. That's a pretty serious weight difference all things considered.