About 3 months ago I had to disassemble and clean the turbo due to the unison ring sticking. After about 2000 miles it's stuck again.

I need your opinion, should I just clean it again, replace the unison ring and canes or replace the turbo?

Obviously I don't want to drop the money for a new turbo but if the $150 for the unison ring and vanes aren't going to be along term fix it would be worth it.

Who has replaced the vanes and ring and did it fix it in the long run?

TIA

 

I would take it out and check what is the problem.
Pictures help also. No need to replace part if it's good. Check the rings holes, are they wider than should be?
Check everything for sign of corrosion, out of round. Is it caked up? Is the cast iron surface heavily pitted? That will answer what to do next.
Do you run your truck short distance alot?

 

I agree.
Also check the actuator pin to see it it has groves worn into it. Not sure if you can get the O-rings to refresh the piston and
cap seals of the hydraulic part of the turbo or not without having to buy a major kit, Might check with Garrett Turbochargers.
Also did you use any anti-seize compound during assembly and if so what type?

 

The actuator pin being the rotating pin that moves the unison ring?

I did. I used Loctite LB 771 Nickel Anti Seize. Rated for 2400 F.

I think maybe I didn't clean the seating surface very good where the inner part of the ring rides against the housing. I was watching video and a guy took a scraper and cleaned that up. I didn't I just cleaned up the surface of the ring and the vanes with a Scotch brite pad.

 

The center of the unison ring where it rides on the the turbo is a place that can be a sticking point.
That along with the face needs to be cleaned with the pads. Only put on a little anti-size. Most of the
oil componet will burn off anyway and it the nickel that is left behind that really does the work. Some
have go as far as to wipe the surface off and what stays behind is all they use. I just use a light
amount and not gob it on. So it looks like you have two places to go back and re-clean. You may as
well do a full cleaning again and see if you have any more pitting or wear.

 

I had used a ceramic paste that became hard over time. I had disassembled the turbo months later again and then used copper paste. >no more problems

 

I'd replace the unison ring first and then go from there before buying a new turbo charger. I replaced mine a few years ago and it has worked well for me so far.

 

+1 on the copper paste. Been going strong for 3.5 years. It also helps to exercise the turbo if you know what I mean; good for the EGR valve too, if you have one.

Also, you should look-up Benchwrench's turbo rebuild thread in the tech folder if you haven't already.

 

So it turns out the unison ring wasnt stuck. The issue was the EBP sensor I replaced a few months ago went bad. Before I bought anything I spent some time watching the gauges on my tuner and realized the EBP values were way off causing the VGT duty cycle to be off.
I cleaned up the old one and put it back in and it works great now.
lesson learned by Motorcraft sensors not what's cheapest...

 

Good to hear you found the cause of the
issue before spending a boat load of cash.