There has been a lot of buzz going around about upgraded thrust bearing so Im going to explain what its all about. Garrett and Borg warner turbos we the only turbo charger companies that used 270 degree thrust bearings. Im not certain why they used the 270 degree thrust bearings, but I do know that their 270 degree thrust bearings were “good enough” for the application that they were used on.
For more durability the 360 degree thrust bearing was needed. The rebuild kits are the same cost however, so its always good to throw in the 360 degree thrust bearing if possible. It is even more neccessary for high boost and performance applications.
Often I have been asked, “can you put a 360 degree thrust bearing in my MHI turbo?” Some people dont realize that the MHI, IHI, ko3/ko4/ko6, and holset turbo chargers (hx35, hx40, h1c, hx52, etc) all have 360 degree thrust bearings from the factory.
This Holset HX35/40 and garret 360 degree thrust bearing have 2 oil fee holes in the thrust bearing for more oil flow which is also very important. The H1c and H1E both can have thrust bearing issues with used around 28 psi, because they only have a single oil feed hole in the thrust bearing it does not get the proper lubrication for higher boost levels. The H1E and H1C have 16cm, 22cm, and 26cm turbine housing which limited the boost level of those turbochargers and the shaft speeds. When those holsets were on a diesel, the turbo never operates at high speeds because the diesel trucks dont turn very many rpms. When the h1c or h1e is put on a gas motor and the car is revved much higher then the turbos thrust bearing will fail. I have a few ideas to fix this problem but never got to test it yet.
The MHI tdo5h/tdo6 turbos do have an aftermarket upgraded thrust bearing system which includes a thicker thrust colar and spacer, and a thrust bearing with two oil journals. Its is a must to have the upgrade thrust bearing in the tdo5h/tdo6 turbo chargers that have heavier rotating assembles such as: tdo6/tdo6h turbines and compressor wheels bigger than 55 mm. The bottom left picture demonstrates where thrust bearing sits which is a on the compressor wheel side of the turbo charger.
The last thing I want to mention about thrust bearings is brass vs steel and why we do not use any steel thrust bearings in out turbochargers. The reason why we don’t use steel thrust bearings in our turbo chargers is because the steel does not dissipate heat well and it doesn’t make for a good “bearing material.” Steel conducts a lot of heat quickly, and when you have a metal shaft with a metal thrust collar and spacer that presses against a metal thrust bearing, then disaster can occur. For turbochargers running steel thrust bearings a special oil is necessary to keep the bearings from fusing together and causing the turbocharger to need a turbine shaft and a full rebuild as a result.
I have even taken new PTE turbochargers apart to throw away the steel thrust bearing and to replace it with a brass bearing because these turbo chargers are having a hard time not needing a rebuild before the first oil change!!