Heavy diesel mechanic based in Toowoomba since 2005
Toowoomba Heavy Diesel is a locally owned and operated heavy vehicle and machinery workshop located in Harristown. Our goal is to keep your vehicles running and at their full, operational capacity. We cater to clients in the mining, earthmoving, automotive, transport, industrial and agricultural sectors.
Established in 2005 by director Ross Martyr, we offer onsite heavy mechanical diagnostics, maintenance, repair, servicing & maintenance monitoring. Additionally, we can come to your worksite with a mobile service truck and offer these services. Our team has the experience to facilitate large vehicles and heavy machinery. Based in Harristown, we have clients across the Darling Downs and beyond.
Flexibility is our strong point. We tailor our mechanical solutions to deliver a competitive customer service experience. When your machinery and equipment is broken or malfunctioning, we strive to get you back into service in a reasonable & efficient manner. We integrate our maintenance solutions to best suit your workloads, schedules, shifts and seasons.
Get in touch with the Toowoomba Heavy Diesel team today and chat to our diesel mechanics about maintenance services for your equipment today.
Our Staff
Ross Martyr
Ross is the sole director of the business with more than 31 years’ experience in the heavy automotive, transport, mining, agricultural and industrial sectors. Completing his trade in Roma, Ross was exposed to a broad range of machinery given the surrounding industries. He gained a solid foundation on which to build his mechanical career. During his 31 years, Ross has worked for a range of heavy equipment repair companies, honing his skills and knowledge.
Jerome Head
Jerome completed his apprenticeship with us, he comes from the Chinchilla farming community. With him he brings a strong understanding of the requirements to maintain, service & repair vehicles & equipment. He completed high school at Grammar in Toowoomba, has been with the company 7 years and is a strong member of our team.
Sam Elmes
Sam was an Augathella local, but his family have moved into the Darling Downs region. Sam graduated year 12 at Toowoomba Grammar school and we congratulate him on completing his HCV apprenticeship and look forward to his ongoing commitment & effort. Sam brings a positive & hard-working package to the team & business, and we look forward to him continuing to grow and learn in the heavy equipment field.
Drew Brewer
Drew is our newest apprentice, Drew is energetic, positive, keen to learn. He has come from the Dalby region, his family own and operate a busy metal working company, so Drew has plenty of welding experience which compliments his skill set. We look forward to seeing him grow and develop as a mechanic.
Jack Wild
Jack has moved in from Inglewood, is an ex builder and is looking to expand his skill set. Originating from a farming family in the Dalby region Jack offers a positive attitude, a view to learn the trade & broaden his mechanical skills. Prior to commencing work with THD Jack was employed by West Haulage & Harvesting Pty Ltd in Inglewood in their workshop as mechanic & operator.
Blake Coleman
Blake has come from Toowoomba Grammar School, has moved to full time employment at the end of 2025 after completing 1 year school based 1 day a week. Blake has some rural exposure. We are excited to see Blake learn, achieve, grow, and develop both as an apprentice and an employee, gaining valuable experience and becoming a key member of our workshop team.
Martin Van Bergen
A qualified tradesman from Victoria, Martin brings extensive experience in heavy automotive work, including trucks, trailers, and equipment. He has previously worked with Broadbent’s and at a Mercedes-Benz dealership, further strengthening his industry knowledge.
We are pleased to welcome him to the team and look forward to him expanding his expertise across a wider range of makes, models, and equipment. We are confident he will be a reliable and valued member of our team.
Katrina Nothdurft
Joining us in mid-2025, Katrina brings strong expertise in parts procurement, inventory management, and quoting. She has extensive knowledge of Kenworth/PACCAR components, as well as truck & equipment parts more broadly.
Katrina is a reliable and valued member of our team, ensuring day-to-day operations run smoothly and supporting an efficient workflow for our fitters. We look forward to seeing her continue to develop her skills, master our systems, and enjoy her time at THD.
Stephanie Brennan
With a background in trucks, automotive, and machinery across both service and parts, Stephanie joined us at the beginning of 2026. We are pleased to welcome her to the team.
Steph has taken on the administrative role of Service Coordinator, where she oversees workflow bookings, manages job-related administration, and supports our fitters to ensure efficient operations and timely job turnaround. Her experience strongly complements the role, and together, Katrina and Stephanie play an integral part in maintaining a smooth and efficient workflow within our workshop.