My Garrett t4 had a bad turbine seal causing a leak into the DP. I ordered a CX Racing t3/t4 repair kit that includes new o-rings, bushings, thrust bearing, snap rings, feed and return gaskets and 6 bolts. I really only needed the piston ring turbine seal, but I figured if I had the turbo apart I might as well replace the basics for only $35. I figured since the kit wasn't a full rebuild that was why it was cheaper than others.... WRONG!

The kit shipped quickly. I ordered it on a wed afternoon and it arrived fri afternoon (cal to az). Fri night I installed the new bushings, turbine piston ring seal and black compressor o-ring seal. Everything else I just left for spares. Well, upon reassembly I noticed that the shaft now had quite a bit more radial play than before. Somewhere in the neighborhood of .060" is my guess. I tore it back down to compare the old bushings with the new. The old bushing's O.D. measured .633". The new bushings measured .619". WTF? Thats almost .015" difference! I don't have a method of measuring the I.D., but just sliding the bushings over the shaft reveals that the old ones are also much tighter then the new. Since the old bushings didn't show severe wear I simply reinstalled them and all is well with the radial play.

Lesson learned. Cheapo rebuild kits don't cut it. Now all thats in the turbo from that kit is the piston ring seal and the o-ring. Maybe those will shit the bed too.

PS. Those bolts that came with don't go to the turbo. They are fine thread. Both the compressor and turbine bolts on my turbo are coarse.

 

Thought I would bring up this old thread to say beware of this. The old turbo was obvoiusly rebuilt once before and had a oversize bore and bearings. It probably had a shaft grind to. The bolts were from a T03 which are metric and most of the cheep kits are from the aisian coutries use metric,TO4'S are imperial.

 

Incorrect. I know the previous owner of the car and know for a fact that the turbo was purchased brand new, from Limit Engineering. Anything else you'd like to tell me about my car?

But good point on the bolt threads. Didn't know that

 

How am I suppose to know that ,you didn't state it in your thread.
When you say the old bearing o/d is .633 that tells me the bore size is .635 which is a standard .015 oversize bearing. Also the old bearings being much tighter on the shaft say the old ones are also oversize to compensate for a shaft grind. If that turbo was a job I needed to rebuild then the turbo bore and shaft size a more than likely been bore and ground. The bearing size from the kit (.619" o/d ) is the correct size for a standard bore garrett housing.

 

Well, it looks like your right. I did some of my own searching around and that OD should be around .620" . Looks like I've been owned. Need to have a talk with the prev owner. Thank you for setting me straight. Maybe I can have this thread removed so as not to tarnish CX Racing's name