There has always been a consistent demand for true Class 8 models. While these heavy-duty conventional cab trucks are reliable, productive, and versatile, the truth still remains that maintaining day-to-day operations with them can be pretty expensive. 

Fortunately, leading manufacturers like Kenworth released Class 7 models that could be modified into Class 8 trucks. This way, business owners can fulfill weighty hauling needs for less operational cost. 

The most famous of these Class 8 alternatives is the Kenworth T370. In this article, we’ll take a look at its rich history and development to see why it has been one of the most in-demand units in the industry.

History of the Kenworth T370

Like other Kenworth units, the T370 underwent upgrades through time.

Kenworth T300

With the rising demand for medium-duty trucks in urban markets, Kenworth released its T300 model in 1994. The T300 was categorized as a lightweight Class 8 truck, which came with a wide selection of 10-liter engines, such as PACCAR PX8, CAT C7, and CUMMINS ISB, among others.


Kenworth T300, the predecessor of the T370

The T300 line also released Aerocab Sleeper variants, which sported the Aerodyne II sleeper cab design. Despite its popularity among delivery companies, Kenworth ceased production and replaced the unit with the T370, T270, and T170.

Kenworth T370

In 2007, Kenworth released 3 alternatives to the T300. The T370, a Class 7 model that could be modified to Class 8; the T270, a Class 6 truck that came with an electric hybrid variant; and the T170, a Class 5 commercial truck. All the trucks on the new lineup, including the T370, sported PACCAR or PX8 engines and were made available with Allison automatic transmissions or Eaton manual shifts. 


The “Baby 8” Kenworth T370

All 3 units were ultimately discontinued in 2021 to make way for the new T180, T280, and T380. Despite this, there has still been a consistent demand for modified versions of the T370, maintaining an impressive resale value.

Other Upgrades of the Kenworth T370

While the T370 didn’t have several major upgrades compared to other Kenworth models, the company released minor modifications to the unit based on the demands of its customers. Most of the changes made were with the axles, which further improved the use of the T370 as a Class 8 conventional cab.

Here are the following modifications done to the T370 throughout its production:

  • 2012 – Kenworth introduced a new heavy-duty front frame assembly option with durable Austempered ductile iron (ADI) cast front drive brackets, 3/8-inch thick steel front adapters, enhanced radiator cross-member brackets, and C-channel front frame winch bumper. The bumper adapters can be used with standard utility, overhead automobile haulers, and emergency vehicles.
  • 2014 – Factory-installed Bendix® ADB22X™ front and rear air disc brakes were made available for new T370 releases.
  • 2015 – At the NTEA Work Truck show, Kenworth unveiled upgraded T370 units featuring heavier front axles. The 18,000-lb to 20,000-lb range was powered by the PACCAR PX-9 engine, capable of producing up to 350hp and 1150 lb-ft of torque.
  • 2015 – Kenworth offered the 10-speed Eaton UltraShift PLUS VAS transmission for the Kenworth T370, T440, and T470, equipped with an 8.9-liter PACCAR PX-9 engine.
  • 2016 – The T370 was made available with non-drive front steer axles rated from 16,000 to 20,000 lbs. and Meritor’s 44,000 and 46,000 lbs. heavy-duty tandem-drive rear axles.
  • 2016 – Added the Bendix® Wingman® Advanced™ system as an option for both T270 and T370. It prevents rear-end collisions through adaptive cruise control with braking and autonomous emergency braking technology.
  • 2017To improve T370’s versatility, wide base tires were now available for applications requiring up to 20,000-lb front axle ratings. This feature enhanced the truck’s overall performance.
  • 2018 – Kenworth made Dana Spicer S140 single-reduction, single-drive axles standard for both T370 and T270. The T370’s Dana Spicer S21-140 was rated at 21,000 lbs.
  • 2020 – The use of a roll-back flatbed body type with Kenworth AG210L single-axle rear suspension was approved for the T270 and T370 models. The Kenworth AG210L is a 21,000-lb rated highway, two-bag, rear air suspension that features a proven trailing arm design, providing a smooth ride.


Design of the Kenworth T370

The concept of upgrading a Class 7 unit to a Class 8 conventional cab truck wasn’t new to the industry when the T370 was introduced. Basically, the idea is to choose a model with a heavy-duty chassis and place a medium-duty power train to increase its payload capacity.


Dependable Kenworth T370

What made the T370 one of the best Class 7 to Class 8 trucks is that it was designed pretty much like a Class 8 conventional cab. Aside from its exterior, it was equipped with tandem rear axles and wide front tires, boasting a 58,000-lb gross vehicle weight rating. This rating is over 20,000 lbs. higher than the base point of Class 8, which stands at 33,001 pounds. 

Due to its design, business owners and truck drivers called the T370 the “Baby 8.” However, there has been an inside joke among users that there’s nothing “baby” about the T370 since it is equipped with a PACCAR PX-9 diesel engine that delivers power like a big truck when in use.

Upgrading the Kenworth T370

Most T370 units have a long lifespan, thanks to their numerous axles, brake modifications, and the common aluminum-made cab. Because of this, most truck owners only need to upgrade the HVAC box to ensure optimal performance.


Plug-and-play Kenworth T370 HVAC box

When buying a T370, it’s imperative to go through the unit’s following parts: thermostat switch, blower motor, evaporator, and heater actuator module. These parts often need to be replaced after an extended period of use. Furthermore, when looking for a new HVAC box for your T370, go with a Shoreline Box, buitl with 18 gauge 304 stainless steel that is spot welded. These HVAC boxes are considered to be the most durable and efficient when it comes to conventional cab trucks.

Fortunately, some premium truck parts providers offer stainless HVAC units with a plug-and-play assembly. This way, you can enjoy the power and comfort of your T370.

Make the Kenworth T370 Your Best Day-to-Day Urban Workhorse

Despite being out of production since 2021, the Kenworth T370 remains one of the most sought-after med-duty trucks. And even though it was coined as a “Baby 8,” the long history of the T370 model showed how powerful it is when it comes to hauling and other utility uses. 


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