BV39 turbo rebuild questions

I started rebuilding my BV39 turbo after it started huffing smoke out the exhaust pipe about 30 min of run time after just putting it back on after a head rebuild and 2.5 inch exhaust install.

I can't seem to find how the VNT vane assembly comes out of the hot side. There are a few videos of the KP39 out there but none for the BV39. There are a few generic pictures from Asian sourcing companies that shoe the assembly for sale and it looks like th screws are in from the back side and its dropped in screw head side first.

Here is a broken link to the Asian sourcing site.
https://m.alibaba.com/product/ [BROKEN] 60526315388/54399700054-VNT-Nozzle-Ring-Turbocharger-Assembly.html?spm=a2706.7843667.1998817009.176.SNfo4r

Also, I may have bent the shaft on disassembly and the compressor wheel doesn't want to budge, even with heat from a mapp has torch so am looking at a replacement cartridge from xsboostturbochargers for $360. It says it's OEM, does that sound legit?

Thanks

They are actually a "non repair" construction, as the VTG mechanics are fixed in the housing with a thin fine thread ring which bakes into the housing like crazy. It is almost impossible to remove the VTG mechanics without destroing the retaining ring, even when using the BorgWarner special tool for it, which clicks into the 3 notches in the retaining ring.
In general I personally even (or especially) as a professional turbo workshop do not repair those bv39 units anymore since a few years.
The basic construction is weak, and prone to fail.
You also need to calibrate the VTG mechanics after repair on a flowbench to ensure proper operation.
If you dismantled the center core completely you need to VSR balance the CHRA after the repair before re-using it. Otherwise it will fail early by big chance.

majesty78 said:

They are actually a "non repair" construction, as the VTG mechanics are fixed in the housing with a thin fine thread ring which bakes into the housing like crazy. It is almost impossible to remove the VTG mechanics without destroing the retaining ring, even when using the BorgWarner special tool for it, which clicks into the 3 notches in the retaining ring.
In general I personally even (or especially) as a professional turbo workshop do not repair those bv39 units anymore since a few years.
The basic construction is weak, and prone to fail.
You also need to calibrate the VTG mechanics after repair on a flowbench to ensure proper operation.
If you dismantled the center core completely you need to VSR balance the CHRA after the repair before re-using it. Otherwise it will fail early by big chance.

Click to expand...

Thanks for the info.
I got a similar answer on the VNT rebuild when I called xsboostturbochargers to ask about their new cartridges. They have a special tool for disassembling them for rebuilds and they end up damaging them on a regular basis and need to reassemble with a new threaded retaining ring. I got as much of the crud build up off of what I could reach and disassemble with the vane assembly still in the housing and left it with a bunch of ATF to help loosen the rest until I can get back to reassemble it.
Will I have to adjust or re-learn the VNT actuator positions when installing a new cartridge? I ditched the rebuild idea since this is going to be a daily driver and will be returning the rebuild kit.
-Alex

If you buy a genuine BorgWarner replacement CHRA, the min flow SHOULD be setup correctly. If you dont have a machine for setting up the actuator, it might be some fiddling around until you got it 100%.

It's a Melett (UK) cartridge so I guess I'll have to look up how to check the actuator with vagcom and adjust the actuator.

Not only the actuator, way more critical is the small so called "minimum flow" worm screw which correct setting lies inbetween 1/4 turn sometimes...correct setting up this screw is only possible with a VNT flow bench.

As example:

https://youtu.be/iYTN8ix9SOM

Well dang...
Thanks again for the info but this is looking more and more like I should have just gone straight to a new or properly rebuilt turbocharger seeing that more special equipment is used. How much of an impact on on performance does that screw adjustment make on end performance.

Do you work at a turbo rebuild/performance shop? I was thinking of a cylinder head and intake manifold flowbench at first before I saw the video since I have accesses to a SF600 but the video cleared that right up.