Rebuilding a turbocharger - Part 2

My G-Pop Shop kit arrived fairly quickly, about a week including the time to go through Canadian Customs. This kit includes all replaceable parts, so if you have a good core you can be sure you'll end up with a good turbo. It's a good idea to compare what's in your kit against your turbo to make sure you have all the parts you need, and more importantly that you won't end up with extra parts that you don't know what they're for.

The bearings in my turbo were well worn. Not only could the shaft wiggle in the bearings, but the bearings could wiggle in the center cartridge. In order to get the bearings out, the snap rings that retain the bearings need to be removed. To do this I ground down the tips of a set of snap ring pliers as these snap rings are tiny. Once you remove those you can pull the bearings out. A dental pick works nicely for this as the bearings have several small oil holes through them which you can use for this purpose. There are 2 bearings, each held by 2 snap rings. The inner rings don't really need to come out and besides, they're difficult to get at.

If you want to sandblast and coat your turbo, now is the time to do it. Just make absolutely sure you clean everything well afterward. I just used a wire brush to get most of the rust off and called it a day since I don't have the equipment to sandblast, or to bake a high-heat coating on.

Oil up the new bearings and slide them into place. There was a noticeable difference between how the old and new bearings fit. It is interesting to note that the original bearings look like aluminum and the replacement bearings are bronze. Replace the outer snap rings, set the new thrust bearing in place on the locating pins and replace the center cartridge-to-compressor backing plate o-ring. Set the center cartridge aside and let's work on the compressor backing plate.

That springy thing retains the thrust bearing. It should come out easily with gentle prying. The new one takes a little more effort to install, I used the old thrust bearing to press mine into place. The compressor oil seal is a 4-piece assembly on these turbos. As you remove it keep track of how it fit together, and remember there's a spring behind it all. Once you replace the seal and the thrust bearing retainer, you can bolt the backing plate back on the center cartridge.

Replace the "piston ring" on the turbine end of the shaft. Try not to expand it too much or you might deform it. I used my snap ring pliers for this. After that, it's time to oil the shaft up and install it. Before you get too far ahead of yourself, don't forget the cup-shaped thingy at the turbine end and the thrust spacer behind the compressor wheel.

Since I haven't found a good torque spec for the compressor wheel nut, I tightened it to "about as tight as the original felt". Highly scientific, I know. Don't forget to line up your index marks you made before tightening the nut.

After that, it's a bolt-it-back-up operation. I used copper anti-seize on all bolts, so should I ever have the need to disassemble this turbo again (but hopefully not) it should come apart with relative ease.