Reviewed by Andrew, 4WD Suspension fitment team
Tough Dog raised rear coil springs for the Isuzu MU-X (August 2014 - July 2021), approximately 40mm of lift, sold per pair. Choose 0-300kg (TDC272) for general touring or Constant 300kg (TDC272H) for permanently loaded wagons, and add the optional Tough Dog coil-insert airbag kit for adjustable load support.
Tough Dog coils are designed and made in Australia from micro-alloyed spring steel – shot-peened, scragged and load-tested, and hot-formed on precision mandrels so the spring keeps its height and rate after years of heavy loading.
Pick the rate for the weight the vehicle actually carries, not the weight you'd like it to carry – and count only permanent accessories and loads (bar, winch, drawers, long-range tank) when choosing. A spring that's too firm for an unloaded vehicle rides worse than the factory item; one that's too soft sags the moment you load up.
Fit springs in pairs per axle, and book a wheel alignment after any change in ride height. It's also worth checking brake-line slack and bump-stop condition while the suspension is apart.
Doing the whole vehicle at once? We also stock the matching assembled Front Struts and front Struts for the Isuzu MU-X 2014-2021.
Matching rear shocks complete the rear end.
Count only constant load (drawers, fridge, camping gear carried daily): general use → TDC272; permanent 300kg → TDC272H. Towing does not count. Contact us if unsure.
| Make | Model | Years | Position |
|---|---|---|---|
| Isuzu | MU-X | August 2014 - July 2021 | Rear |
Choose the load rating for the weight the vehicle carries most of the time, counting only permanent fitments such as a bar, winch, canopy or drawers. A heavier rating than you need rides firm when unloaded; a lighter one sags once the gear goes in.
| Part number | Lift | Load rating | Suits / notes |
|---|---|---|---|
| TDC272 | 40 mm | 0-300 kg | - |
| TDC272H | 40 mm | Constant 300 kg | - |
Rear coil springs are changed with the axle supported and the lower shock mount unbolted so the axle can drop far enough to slip the old spring out. Check brake hoses, ABS leads and the breather have enough slack at full droop, especially with raised springs, and fit both sides together. Raised springs need shock absorbers with the correct extended length for the new ride height. In most states a suspension lift of up to 50 mm is allowed without certification under VSB14; larger lifts can require engineering approval, so check the rules for your state.
Last updated: 10 September 2026
Genuine Tough Dog suspension from an authorised Australian dealer.
New to D-MAX and MU-X suspension? Read our D-MAX and MU-X suspension problems guide.
| Specification | Detail |
|---|---|
| Brand | Tough Dog |
| Type | Rear coil springs |
| Position | Rear axle |
| Sold as | Pair (both sides) |
| Vehicle | Isuzu MU-X 2014-2021 |
| Lift options | 40 mm |
| Load ratings | 0-300 kg, Constant 300 kg |
| Part numbers | TDC272, TDC272H |
| Construction | Designed and made in Australia from micro-alloyed spring steel; shot-peened, scragged and load-tested |
Load ratings refer to permanent extra weight over the axle. Springs do not change the vehicle's GVM or towing capacity.
Both springs in this listing are approximately 40mm raised, so the matching Tough Dog coil-insert kit is the 40mm Lift version (TDAA-005) - the OEM-height kit does not suit these springs.
These suit the following applications: Isuzu MU-X August 2014 - July 2021 Rear. Check your build date and variant against the fitment table on this page – if you're not certain, contact us with your rego or VIN details and we'll confirm fitment before you order.
Match the rating to the weight the vehicle carries all the time – count only permanent additions (bar, winch, canopy, drawers, long-range tank), not luggage or towball weight. The options on this page cover 0-300kg, Constant 300kg, 300kg. If the vehicle is mostly unloaded, stay at the lighter end; going too firm hurts the unladen ride. Still unsure? Send us your setup and we'll confirm the right spring.
The listed price covers both sides – always replace left and right together so the axle is evenly damped and sprung. It's a bolt-in job for a competent home mechanic or any workshop; check bushes, mounts and brake-line slack while everything is apart.
The options on this listing are: 40 mm. Lift is measured at ride height with the vehicle's normal load. Raised springs need matching shock absorbers with the correct extended length.
Yes. The price covers both Tough Dog springs, one for each side.
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