GT1446V 55565353 Turbocharger for Chevy Cruze Sonic Trax Buick Encore 1.4L
55565353, 781504, 781504-5001S, 781504-5002S, 781504-5004S
GMC Turbocharger
New Replacement Turbochargers for GMC Sierra HD Duramax Diesel and GM EcoTec Engines
GMC Sierra 2500HD and 3500HD trucks run the same Duramax diesel as the Chevy Silverado — and the same turbocharger. The Duramax has used two turbo families across its production life: the IHI RHG6 on the original LB7 from 2001-2004, and the Garrett GT3788VA from the LLY through LMM era (2004.5-2010). Both are VGT (variable geometry) designs that control boost through a movable vane mechanism — and both eventually fail from soot loading, vane sticking and bearing wear at high mileage. We stock brand new replacements for both generations, matched by engine code and part number. We also carry the BorgWarner GT1446V for the GM EcoTec turbocharged platform. Every unit is new-built, balanced, and verified before it ships. Shops, fleets and distributors order from US stock.
- 100% Brand New
- OEM-Spec Quality
- US Stock, Fast Dispatch
- Direct-Fit Replacement
- Exact Part-Number Match
- 1-Year Warranty
- No Core Charge
LB7 Through LMM Duramax — Every Generation In Stock
The Duramax turbo job is bread-and-butter work for GM diesel shops — and it comes in waves as fleet trucks age into the mileage window where VGT mechanisms start failing. The ordering challenge is that the LB7 turbo (IHI) and the LLY/LBZ/LMM turbo (Garrett) are completely different units from different manufacturers, and within the Garrett family there are part number variations by year. We carry both and sort the match before the part ships.
LB7 IHI and LLY/LBZ/LMM Garrett Coverage
Every Duramax turbo we ship is 100% new — new CHRA, new vanes, new housings. No core deposit tying up cash, no old unit to crate and freight back. The Duramax reman market is notorious for poorly rebuilt vane mechanisms that stick within months — a new unit removes that gamble.
Same Turbo Fits Sierra HD and Silverado HD
We stock the IHI RHG6 for the LB7 (2001-2004 Sierra and Silverado HD) and the Garrett GT3788VA for the LLY, LBZ and LMM era (2004.5-2010). Two turbos cover the entire first decade of the Duramax program — the years that are now hitting high-mileage turbo service.
VGT Vane Diagnosis Before Ordering
The GMC Sierra HD and Chevy Silverado HD use the same Duramax engine and the same turbocharger. We cross-reference both GM part number catalogs and match by VIN or engine code — same turbo regardless of badge.
Engine Code Verification on Every Order
The Duramax VGT fails in a predictable pattern: exhaust soot loads the vanes, the unison ring starts to drag, the vane position sensor throws codes (P003A, P2563), and eventually the vanes lock open or closed. Before ordering a full turbo, pull the intake pipe and inspect the vane mechanism — if the vanes move freely, the actuator or sensor may be the only failure. We walk through this with shops on every call.
Ships New and Complete, No Core
Duramax turbo replacement is volume work for GM diesel shops — pricing is structured for that reality. Consistent wholesale cost from single units to fleet restocks, all from US inventory. See the wholesale program.
Volume Pricing for GM Diesel Shops
One-year warranty on every turbo, handled by our US team. On the Duramax, we check the kill chain before shipping — oil quality, drain-back line condition, and EGR soot load. A new turbo on a truck with a clogged drain line or failed EGR cooler is a guaranteed comeback. See the warranty page.
LB7 IHI and LLY/LBZ/LMM Garrett Coverage
Every Duramax turbo we ship is 100% new — new CHRA, new vanes, new housings. No core deposit tying up cash, no old unit to crate and freight back. The Duramax reman market is notorious for poorly rebuilt vane mechanisms that stick within months — a new unit removes that gamble.
Same Turbo Fits Sierra HD and Silverado HD
We stock the IHI RHG6 for the LB7 (2001-2004 Sierra and Silverado HD) and the Garrett GT3788VA for the LLY, LBZ and LMM era (2004.5-2010). Two turbos cover the entire first decade of the Duramax program — the years that are now hitting high-mileage turbo service.
VGT Vane Diagnosis Before Ordering
The GMC Sierra HD and Chevy Silverado HD use the same Duramax engine and the same turbocharger. We cross-reference both GM part number catalogs and match by VIN or engine code — same turbo regardless of badge.
Engine Code Verification on Every Order
The Duramax VGT fails in a predictable pattern: exhaust soot loads the vanes, the unison ring starts to drag, the vane position sensor throws codes (P003A, P2563), and eventually the vanes lock open or closed. Before ordering a full turbo, pull the intake pipe and inspect the vane mechanism — if the vanes move freely, the actuator or sensor may be the only failure. We walk through this with shops on every call.
Ships New and Complete, No Core
Duramax turbo replacement is volume work for GM diesel shops — pricing is structured for that reality. Consistent wholesale cost from single units to fleet restocks, all from US inventory. See the wholesale program.
Volume Pricing for GM Diesel Shops
One-year warranty on every turbo, handled by our US team. On the Duramax, we check the kill chain before shipping — oil quality, drain-back line condition, and EGR soot load. A new turbo on a truck with a clogged drain line or failed EGR cooler is a guaranteed comeback. See the warranty page.
WHY CHOOSE US
Duramax turbo supply, matched by engine code every time
We verify the Duramax engine code (LB7, LLY, LBZ, LMM) and cross-reference the GM part number before dispatch. US stock, same-day shipping on most orders, and real support after the sale. More about our company and quality process.
FAQ
By engine code: the LB7 (2001-2004) uses the IHI RHG6 turbocharger. The LLY (2004.5-2005), LBZ (2006-2007) and LMM (2007.5-2010) all use the Garrett GT3788VA, though part numbers vary between years. Match by the engine code on the emissions label or by the part number on the old turbo.
Yes. The GMC Sierra HD and Chevrolet Silverado HD share the same Duramax diesel engine and the same turbocharger. The turbo part numbers are identical across both badges for the same engine code and model year.
The Duramax turbo is a variable geometry design that controls boost through a set of movable vanes inside the turbine housing. Over time, exhaust soot coats the vanes and the unison ring that synchronizes them. The ring starts to drag, the vanes respond sluggishly, and eventually they stick open or closed. High idle time, short trips and marginal oil change intervals accelerate the process. The second most common failure is bearing wear from oil drain-back restriction — sludge in the drain line holds oil in the bearing housing and cokes on hot shutdown.
No. The LB7 uses an IHI turbo (RHG6) and the LBZ uses a Garrett turbo (GT3788VA). They are completely different units from different manufacturers with different mounting, plumbing and electronic connections. They are not interchangeable.
All units are 100% brand new. No rebuilt cores, no core charge, nothing to return. New CHRA, new vane mechanism, new housings. Balanced and OEM-spec. One-year warranty.
Yes. GM diesel shops and fleet maintenance operations order Duramax turbos as regular volume parts. Consistent wholesale pricing from US stock. See the wholesale page.
GMC Duramax Turbocharger Guide
The Duramax diesel has powered the GMC Sierra HD and Chevy Silverado HD since 2001, and its turbocharger system has gone through several distinct generations. Knowing which generation your truck runs determines the turbo you need and the failure patterns you should expect.
Duramax Turbo Generations
| Engine code | Years | Turbo | Manufacturer |
|---|---|---|---|
| LB7 | 2001-2004 | RHG6 | IHI |
| LLY | 2004.5-2005 | GT3788VA | Garrett |
| LBZ | 2006-2007 | GT3788VA | Garrett |
| LMM | 2007.5-2010 | GT3788VA | Garrett |
The LML (2011-2016) and L5P (2017+) Duramax engines use updated turbo configurations not currently in our catalog. We cover the LB7 through LMM — the generations now reaching the mileage range where turbo replacement is common.
LB7 RHG6: The First-Generation Duramax Turbo
The original Duramax LB7 used an IHI-manufactured RHG6 turbo — the same manufacturer behind Isuzu commercial truck turbos. The LB7 is known more for injector problems than turbo problems, but at 200,000+ miles the turbo shows bearing wear, shaft play and VGT mechanism fatigue. The RHG6 is a different physical turbo than the Garrett units used on later Duramax engines — they are not interchangeable.
LLY/LBZ/LMM GT3788VA: The Garrett Era
Starting in 2004.5, GM switched to the Garrett GT3788VA across the LLY, LBZ and LMM engine codes. This turbo uses a unison ring to synchronize the vane assembly — a mechanism that Duramax owners know well because soot eventually jams it. The LLY was particularly prone to overheating issues (restricted intake tract from the factory air box), which loaded the turbo with higher EGTs and accelerated vane sticking. The LBZ and LMM improved airflow management but still use the same basic turbo design.
Duramax VGT Failure Diagnosis
- Vane position codes — P003A (turbo boost position not learned) and P2563 (turbo boost position sensor performance) indicate the vane mechanism is not responding correctly to ECM commands.
- Slow spool — If the truck feels sluggish under load and EGTs run high, the vanes may be stuck partially open, reducing exhaust backpressure on the turbine wheel.
- Over-boost or surging — Vanes stuck partially closed create excessive backpressure and boost spikes. The truck may feel strong initially then surge or hunt for steady boost.
- Manual vane check — With the intake pipe removed, the vane mechanism can be inspected and moved by hand. Smooth, free movement across the full range means the mechanism is healthy. Any binding, grit or dead spots indicates replacement.
Replacing a Duramax Turbo: Key Steps
Flush or replace the oil drain-back line before installing the new turbo — carbon buildup in the drain line is the leading cause of Duramax turbo bearing failure. Check the turbo oil feed line for restriction. Inspect the charge-air cooler for oil contamination (a sign the old turbo was leaking oil into the intake). On LLY trucks, confirm the intake tract has been addressed — the factory air box restriction that causes LLY overheating will load the new turbo with the same excessive heat. Prime the new turbo with oil through the feed port, hand-spin the shaft, and idle for several minutes before loading the engine.
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