How To: Rebuild Your Own Turbo

On the lower right, you can see the Garrett turbo rebuild kit from BECS Pacific (GTP38 Kit), which included a new thrust bearing assembly, back plate seal, brass journal bearings, and piston ring seals. The compressor wheel was also replaced with a stock replacement (Schwitzer PN 170293, which is known to enthusiasts as a Wicked Wheel). Xtreme Diesel Performance also sells this compressor wheel for just $75.50.

On the lower right, you can see the Garrett turbo rebuild kit from BECS Pacific (GTP38 Kit

Turbochargers are expensive. There's no denying that. Even an OE replacement can cost you up to $1,000. But, if your diesel engine needed new piston rings and a simple rebuild, you wouldn't swap in a whole new motor, would you? Much like aging diesel engines, the turbochargers equipped on them don't have to be thrown away when they need a little freshening up, they can be rebuilt easily, and on the cheap.

Maximum Diesels in San Jacinto, California, was in the process of rebuilding a stock Garrett TP38 journal bearing turbo from a '97 7.3L Power Stroke and let us take a look to see for ourselves how easy it is to do. This is no massive undertaking, as the overhaul can be performed by anyone, takes less than an hour to complete, involves working with very simple mechanical components, and costs less than $200 in parts.

The rebuild candidate hadn't failed, or even really been abused (judging by the wear on its components). The turbo's compressor housing was secured to the back plate by four bolts, which required a 12-point, 8mm socket to remove them (it's important to use the right tool here, because if you don't use a 12-point socket, you could round off the bolts).

The rebuild candidate hadn't failed, or even really been abused (judging by the wear on it

The only tools required are: a 5/8-inch socket, 12-point 8mm socket, 18mm socket, rubber mallet, torque wrench, silicone, snap-ring pliers, and a vise. Follow along, as we've outlined step-by-step instructions for any do it yourselfer willing to tackle this simple task.

Diy Turbo Rebuild Exhaust Backpressure Valve

EBV Delete:
While the turbo was off, the guys at Maximum Diesels also removed the exhaust backpressure valve (EBV). The EBV acts as a choke in cold weather and is actuated by oil pressure and according to oil temperature. On cold days, the butterfly will stay closed until operating temperature is reached.

To remove it, the two tabs that attach the butterfly valve to the shaft are simply cut off (yellow arrow). You remove the butterfly (red arrow), and then pull the shaft out (blue arrow). A 3/4-inch freeze plug (green arrow) can be pressed in on the other side and used to plug the shaft hole. The pedestal has to be modified as well but is also relatively simple. First, the snap ring is removed, the EBV actuator (rod and spring assembly) is pulled, and then the oil inlet for the EBV actuator can be tapped to accept a 1/4-inch pipe plug. This stops oil flow to the area.

By deleting the EBV you lose the factory cold warm-up option, but with custom tuning (which many 7.3L trucks have) a high-idle option is warm-up enough in cold weather. Plus, gutting the EBV is thought to lower EGT, improve exhaust flow, and provide one less failure point on '941/2 to '03 7.3L Power Stroke engines.

Once the compressor housing was pulled, we confirmed that no excessive shaft play was present, the compressor wheel blades looked decent, and the back plate still had a smooth, uncorrupted surface (the back plate can become scarred when shaft play allows the wheel to make contact with the compressor housing).
Once the compressor housing was pulled, we confirmed that no excessive shaft play was pres
The compressor wheel nut was loosened using a 5/8-inch socket and an 18mm socket on the turbine wheel nut. It's important to note that '991/2 to '03 turbos on Super Duty 7.3Ls have an S nut on the turbine wheel, which requires a special socket or wedging something in the turbine wheel to stop it from spinning during disassembly. Also notice that the exhaust backpressure valve chamber has been removed from the turbine housing (see the EBV Delete sidebar).
The compressor wheel nut was loosened using a 5/8-inch socket and an 18mm socket on the tu
With the compressor wheel off the shaft, a 12-point, 8mm socket was used to remove the four bolts (arrows) that secure the back plate to the center cartridge.
With the compressor wheel off the shaft, a 12-point, 8mm socket was used to remove the fou

Next, the thrust bearing assembly was inspected and removed. This is where the turbo's mainshaft support lies. The thrust collar and thrust washer reside in this area, and the shaft rides on a thin coat of oil between the two. The result of thrust assembly failure is excessive shaft play, scarring on the shaft, and eventually the compressor wheel making contact with the compressor housing.
Next, the thrust bearing assembly was inspected and removed. This is where the turbo's mai
When removing the four 12-point bolts that hold the center cartridge to the turbine housing, we made sure to first soak them with PB Blaster. Be prepared to fight at least one of the bolts, as they've no doubt seen thousands of heat cycles in their lifetime. Once all four bolts were out, we gently pried the turbine housing away from the center cartridge, and then subtly tapped the compressor wheel end of the shaft with a rubber mallet to remove it.
When removing the four 12-point bolts that hold the center cartridge to the turbine housin
The circular back plate seal in the center cartridge was removed and replaced. As a side note: The later-model (Super Duty) turbo back plates are different, and the seal is cross-shaped instead of circular. Our rebuild kit, which works for either turbo, came with both seals.
The circular back plate seal in the center cartridge was removed and replaced. As a side n

Next, the large piston seal ring on the turbine side of the shaft was removed (the other goes on the compressor side) and the area was cleaned with brake cleaner and a wire brush and replaced with the one supplied in the rebuild kit (shown).
Next, the large piston seal ring on the turbine side of the shaft was removed (the other g
With one of two provided brass journal bearings in the turbine side of the center cartridge, a thin coat of oil was applied to the shaft as well as inside of the center cartridge before reinstallation. When reinstalling the shaft, we worked the wheel back and forth to ensure no damage was done to the new piston seal ring.
With one of two provided brass journal bearings in the turbine side of the center cartridg
Then, the center cartridge spacer was installed on the compressor side (shown), followed by the second supplied brass journal bearing, and then the second (and smaller) piston seal ring, which goes on the thrust collar. Then the turbine wheel and shaft assembly-as well as the center cartridge-were reinstalled in the turbine housing.
Then, the center cartridge spacer was installed on the compressor side (shown), followed b

From there, the new thrust washer was installed in the back plate, followed by the new thrust collar. After that, the back plate was fastened to the center cartridge (it can only be installed one way). The four 12-point bolts were torqued to 12 ft-lb.
From there, the new thrust washer was installed in the back plate, followed by the new thr
Next, the new compressor wheel was threaded onto the shaft and torqued to 10 ft-lb. Then a bead of silicone was applied around the outer edge of the back plate.
Next, the new compressor wheel was threaded onto the shaft and torqued to 10 ft-lb. Then a
Once the compressor housing was reinstalled, its four 12-point bolts were torqued to the recommended 12 ft-lb specification.
Once the compressor housing was reinstalled, its four 12-point bolts were torqued to the r

SOURCES
BECS Pacific 2825 Pellissier Place San Bernardino CA 90601 888-359-3999 www.becspacific.com	Xtreme Diesel Performance 1758 State Route 34 North Wall Township NJ 07727 888-343-7354 www.xtremediesel.com
Maximum Diesels N/A AK 951-634-9595