How Much Space Do You Need Between Dually Tires?

How much space do you need between dually tires

Are you considering upgrading to a wider tire on your dually? Are you concerned about what the maximum width is you can go on a stock rim? Are you perhaps considering switching to 265/70/17 and want to know what the minimum space is between the rear tires?

The recommended minimum spacer size between the rear dually tires is a 1/2″ (1.27cm). This will be safe at maximum load capacity and will prevent any small debris from getting lodged between the rear tires which could result in premature wear and punctures. Tire sizes like 235/85R16’s are a popular choice on 6.5″ wide factory stock dually wheels.

How Much Space Do You Need Between Dually Tires? SIZE MATTERS!

It’s important to understand the space difference between the rear tires when inflated versus being deflated, or when carrying heavy loads. A 1/4 an inch spacer is not wide enough under full load. If the side walls touch while loaded, it will chaff, overheat the side walls, and possibly causing a blowout.

Therefore, it’s important to ensure the width of the tire is not too wide, and that the side walls never touch under any application that you use your pickup for.

It’s widely agreed by many dually owners that the 1/2″ spacer is sufficient enough, as long as the tires are’nt too wide and they do not make contact on a constant travel, or they are too close to allow debris and rocks to get jammed in-between the tires.

Many Dually owners successfully run a 1/2″ spacers between the duals to give more clearance without any hassles. However, some dually owners frown against spacers since they view it as unsafe.

Are spacers safe for most applications?

How does spacers affect the wheel dynamics on a Dually?

Many believe spacers are unsafe since they alter where the load is distributed on the hub, and add more strain on the studs and bearings. Differences in road surfaces cause variations in loads on a set of duals. This means that it is common for the center of the load on a set of duals to be constantly shifting. Keeping that in mind means that a spacer could potentially have a negative effect on your wheel bearings over the long-term if you often drive on uneven surfaces while carrying heavy loads or towing.

What about the wheel studs?

When wheel studs are not torqued properly, it could result in uneven weight distribution which could cause metal fatigue and premature failure.

If the wheels are not seated correctly or fitted tightly against the hub, it results in the studs carrying more of the load. Therefore its important to fit hub-centric spacers to get the wheel centered properly. The clamping force from 8-9/16″ studs at 60% yield is significant, however it could still result in premature failure if not seated and mounted dead center.

However the opposite is also true, that when the wheel is fitted tightly with hub centric spacers and carrying the load evenly while the studs only clamp to prevent spinning, then there is no pressure or unnecessary load on the studs.

Another factor to remember is the tires load carrying characteristics in dually applications. If the tires are too close they don’t have sufficient heat dissipation, thus making them more vulnerable to blow outs.

Will 35” Tires Fit Stock Dodge Ram 3500 Dually?

In order to fit 35” tires to a Ram Dually, you’ll need a minimum 2” front leveling kit combined with well-engineered hub centric 1/2”steel spacers between the duals, running 35×12.5 tires.

This combination offers sufficient clearance to prevent rub and scrubbing at full lock in front. It also allows enough space between the rear tires for sufficient heat dissipation. Always make sure you opt for high grade quality steel spacers, and not cheap aluminum versions. Make sure you fit a 1/2″ spacer on the rear to prevent the tire chaffing on the rear leaf packs.

Running 35 inch tires on a Ram Dually (Spacers vs Aftermarket rims)

Tire upgrades can be expensive and when doing any big tire upgrade, there’s always the inexpensive method and then there’s the correct method. With that being said, there are many Dually owners who’ve opted for spacers instead of fitting aftermarket rims without any hassles at all. However, if you really want to run 35’s on the dually, if possible, invest in a set of rims that does not require wheel spacers.

It is highly recommended to opt for a wider wheel with the correct offset. This allows you to maintain the carrying capacity of the truck, since they are properly sized and designed for the larger tires you intend to run. Just make sure you find a decent aftermarket set that doesn’t look tacky.

35 inch tires on a Ram Dually (Not all 35’s are created equal)

Certain tire brands have bigger side lugs, with a more aggressive tread pattern, resulting in more rubbing, so your tire choice plays a major role. Toyo tires are known to be a good option since they fit well.

A truck with an empty tub can be very jittery and bumpy, so many owners deflate the tires for a more comfortable ride. However, if your tires are too wide, once you deflate them they have a higher risk of rub. The best option without running spacers is a set of 255/80/17s, as long as you keep the tires inflated. 35×12.5s tires will fit perfectly provided you have spacers in between the duals.

Modifications to prevent Rubbing

I find this tool very useful when determining tire size differences and what effect it has on your truck: https://tiresize.com/comparison/

Next, let’s investigate the biggest tires you can possibly squeeze on a Ram 1500 with a stock suspension.

Biggest Tire Size on Stock Ram 1500

So this is probably one of the most commonly asked questions on all discussion forums and FB groups. Every guy wants to know what the biggest tires are he can get away with on a factory stock suspension and stock wheels.

If you are prepared to live with following:

  1. Rub on the sway bar
  2. Rub on the radius bar fastener
  3. Light trimming inside the wheel well liner
     

Physical Difference between a 33” vs 35” Tire
 

Measurement33-Inch35-inchDifference
Diameter285/75/17305/75/17+7%
Width11.2”12”+7.1”
Sidewall7.9”9”13.9”
Circumference102.7”109.9”+7%
Revs/Mile617576-41

Biggest Tire on 2019 Ram 1500 with Stock Rims

The biggest tire you can fit on a Ram 1500 with stock rims are 37”x12.5 

As mentioned, you will need to do a little bit of trimming on the inside fender liner. This applies to 2500, 3500, and Power Wagon stock wheels. The Power Wagon wheel has a slight advantage since it has a wider offset wheel in stock form, meaning there is a bit more backspace clearance.

Resources

Ram 1500 2” Front leveling kit

Full 2” Lift Kit

Adjustable Shocks

Conclusion

Going bigger tires might look awesome, however you want to limit how big you go, especially if you still want to maintain full functionality of your truck. Bigger isn’t always better since the bigger you go, the more modifications you’ll need to make.

 

Jade C.

4-Wheel drives and off-road driving techniques has been my passion for over 20 years. Here we strive to provide the most accurate, up-to-date, information about the functionality, common faults and latest technology built into most 4 Wheel Drives.

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