Turbo balance

Hello all, I think I screwed myself....

So I bought an old Air Research T3 turbo a while back, it was advertised as having been re-built recently. There is a bolt missing on the exhaust housing and today I decided to take it apart so I could replace the bolt.

Missing bolt:

However, being an idiot I just started taking things apart without marking where they came from, so now I've taken off the compressor wheel, and I have no way of knowing which way it was originally put on. Now I'm pretty sure I just ruined my chance of having the turbo put back together balanced like it was factory, but maybe not because the compressor wheel looks like it has some material taken away from it already, so maybe it has been balanced seperately and not together as a unit? The pencil mark I put on there because there was a previous pencil mark some one else had marked on there (It was faint so I re-drew it), but I can't find any other pencil markings on the rest of the turbo as to where it might line up with.

Here's a shot of the turbine side where there are more balancing cuts on the nut:

And to top things off I found out why there was a missing bolt:

The turbo also has the compressor cover swapped at some time in it's life, and this has caused issues with the wastegate mounting bracket:

So should I

-just use it for parts

-put it together again as is and see what happens when I use it

-fix it

If I fix anything

-should I bother with the bolt how, how important is it to have equal torque holding on the exhaust housing...I imagine it expands and contracts ALOT

-do I need to rebalance the turbo or is it already balanced individually and not the whole rotating assembly...and again how important is the balance

It does have minimal shaft play otherwise.

I value your opinions!

Send it to a rebuilder that can blance it unless you know how/have tools for it is my vote...

T3's are dirt common and dirt cheap. Find another one.

Run_Away wrote: -should I bother with the bolt how, how important is it to have equal torque holding on the exhaust housing...I imagine it expands and contracts ALOT

Pretty important to get all the same torque.. just get it pretty close and you should be ok..

-do I need to rebalance the turbo or is it already balanced individually and not the whole rotating assembly...and again how important is the balance

yes.. The company will balance each component seperately and then use a core balancer to phase the compoenets to each other. What they are effectively trying to do do is have the imbalances in each part try to negate the other. Yes.. You need to balance the parts. You might get lucky putting it back together, however, you could really screw it up.

I would bolt it back together and run it - and I wouldn't suggest it unless I've done it myself, more than once, with the same turbo.

I can't think of a more popular turbo, and I think their popularity stems from the fact that they're stout, reliable little units - able to live in common production cars for tons and tons of miles. Between Ford, Volvo, SAAB and Chrysler, there has to be millions of those thing out there.

The first time I ever took the housings off I was all freaked out about how tough they were to get off (the turbine side, anyway), and how they seemed to jam against the wheel until you'd tighted it down and square it up. I was pretty paranoid about it until I'd done it a couple times. Now? I know that they do hit a little when you put them together, but it doesn't cause an issue (you'll get a feel for it). They square up when you tighten them down.

As for that bolt hole, you could try a heli-coil if you can get one that small, or weld it up and re-drill and tap it (which would be trickier, I think). If you tighten down the turbine housing with the three that you DO have, and the wheel won't hit anywhere even if you try to make it hit, you'll probably be OK.

If you decide to just get a replacement, finding one should be simple if you want a .48 housing - they're dirt cheap on turboford, since all those guys want the .63 housing.

T3s are like the small-block Chevy of turbos.

Yup, my Pontiacs use a BIG T3 and they're pretty bulletproof.

I've put a couple back together with no trouble. Usually I mark the wheel and shaft but I have forgotten before.

Shawn