Holset HY35W Turbocharger Parts
Genuine Holset/Cummins Parts vs Cheap Aftermarket
The market is flooded with cheap, low quality turbocharger rebuild kits. While they are significantly less expensive than the genuine Holset products available through your local Cummins parts dealer, their quality is extremely questionable. These cheap imitation are often marketed as "Genuine" Cummins/Holset products at various online marketplaces. The simplest way to spot an imitation is to look at the journal bearings.
Note the ring machined into the Holset bearing for proper lubrication.
The OEM replacement bearings manufactured by Holset and sold through Cummins dealers feature a machined groove traveling the entire circumference of the bearing at its center. Note that this groove, which is important for proper lubrication, is absent from the imitation being sold as a genuine Holset product.
The Holset washer is machined to a higher degree of precision than its cheap counterpart.
As with the Holset journal bearings, the OEM thrust washer is machined to a greater degree of precision and has minute features that are absent from the imitation. We highly recommend rebuilding your turbocharger with genuine replacement parts and avoiding the cheap, foreign made alternatives on the market.
HY35W Turbocharger Rebuild Parts List
| Part Description | Part Number(s) | Remarks/Notes |
| HY35W service kit | Holset 4031484 | [1] |
| Compressor wheel | Various | [2] |
| Turbine shaft/wheel assembly | Holset 3519336 | [3] |
| Turbine housing to bearing housing Marman clamp | Holset 4036551 | --- |
| Oil supply tube fitting | Cummins 4940183 | [4] |
| Oil supply tube | MOPAR 68002982AA Cummins 4935577 |
[5] |
| Oil drain tube gasket | Cummins 5264568 | [6] |
| Oil drain tube/hose | MOPAR 5086950AA | [7] |
| Up-pipe flange gasket | Cummins 3755843 | [8] |
| Downpipe Marman clamp | MOPAR 52103596AC | --- |
| High temperature anti-seize lubricant | Loctite LB 8009 Permatex 77124 Motorcraft XL-2 |
[9] |
[1] Service kit includes journal bearings, oil seals, thrust washers, etc.
[2] Various aftermarket billet compressors available.
[3] Replace as necessary if turbine wheel is damaged or oil seal lands are scarred; generally reused.
[4] Includes seals; recommend replacing during turbo service.
[5] Replace as necessary; does not include fittings or seals.
[6] Required for reinstallation of the turbocharger; do not attempt to reuse.
[7] Replace as necessary; includes oil drain tube, gasket, and seal.
[8] Required for reinstallation of turbocharger; inadvisable to reuse.
[9]
All listed products have a max temperature rating of 2,400 ° F and are therefore suitable for use on turbochargers.
How to Rebuild a Holset HY35W Turbocharger
The turbocharger should be assembled on a clean workbench free of dust, debris, and contaminants. Turbos operate at incredibly high speeds, thus they should repaired with care. All o-rings, bearings, and related components should be coated (or soaked) in clean engine oil prior to installation to ensure proper sealing, fitment, and operation.
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• Compressor wheels are entirely reusable so long as they are not damaged and/or excessively worn. Thoroughly inspect the compressor for shape and form before making the decision to reuse.
• The edge of the blades on the compressor wheel inducer pictured at left have small wear marks indicating poor filtration; it will not be reused.
• Soak the thrust bearing and small oil ring seal in clean engine oil, then install the oil ring onto the appropriate land on the thrust bearing. Be cautious not to mar the sealing surfaces of the thrust bearing.
• Soak the large oil ring in clean engine oil, then install onto the appropriate land on the turbine wheel shaft. Be cautious not to mar the sealing surfaces of the turbine shaft assembly.
• Soak the journal bearings and snap rings in clean engine oil. Install the lower snap ring on the compressor side of the center section.
• Install the journal bearing, followed by the upper snap ring that secures the bearing in place.
• Coat the thrust collar in clean engine oil, then install atop the journal bearing with the wider portion sitting above the bearing.
• Coat the thrust washer in clean engine oil, then install atop the thrust collar. Ensure the alignment pins engage the appropriate holes in the washer; orientation should match that pictured, i.e. do not install upside down, the position is vital to proper lubrication.
• Install the thrust bearing into the oil cap. The oil ring should snap into place securely if installed correctly.
• Coat the oil cap o-ring in clean engine oil, then install on the oil cap.
• Install the oil baffle inside the oil cap.
• Thoroughly coat the entire assembly with clean engine oil.
• Install the oil seal assembly (with baffle, o-ring, and thrust bearing) into the center section. Secure with the appropriate snap ring, ensuring that the snap ring seats properly.
• From the turbine side, install the lower journal bearing snap ring, followed by the journal bearing, and finally the upper journal bearing snap ring (all components should have been soaked in clean engine oil).
• Set the center cartridge on the workbench with the oil inlet facing upwards (small threaded hole, not the two bolt flange). Coat the entire turbine shaft, particularly around the oil seal, with clean engine oil and install the turbine wheel heat shield over the shaft.
• Insert the shaft into the center section with the oil ring gap facing upwards. The oil ring gap must align with the oil inlet location or a leak may develop. The oil ring will snap into place once properly seated; excessive force should not be required.
• Install the compressor wheel and torque to 133 in-lbs if shaft uses 6 point nut, 124 in-lbs if shaft uses a 12 point nut. Note - inch pounds, NOT foot pounds. If reusing a compressor wheel, ensure to line up index marks on tip of compressor wheel and shaft made during disassembly.
• Coat the sealing surface of the turbine housing with a high temperature anti-seize lubricant.
• Line up and install the turbine housing to the center section. Install the Marman clamp and torque to 75 in-lbs. Tap turbine housing with a dead blow hammer several times and re-torque.
• Coat the compressor housing o-ring with clean engine oil (if applicable), then install on the appropriate flange of the center section.
• Line up and install the compressor housing; secure in place with large snap ring. Ensure that the snap ring is fully seated.
• Reinstall wastegate actuator and wastegate actuator linkage.
• Reinstall silencer ring at compressor housing inlet.
• IMPORTANT - Turbocharger bearings must be pre-lubed before operating; after installing turbocharger onto exhaust manifold, install turbo oil drain tube. Pre-lube the turbocharger bearings by pouring a small quantity of clean engine oil through the turbo oil inlet while rotating the shaft via the compressor wheel. Finally, install the oil feed line.