I'm knuckles deep into tearing down the turbo on my '81 SD.
It is a AiResearch = Garrett T3.
I have a standard rebuild kit coming for my birthday (next week) ... knowing that the current turbo has likely seen zero service despite more than 200K miles... But now that i have the unit apart, I'm wondering if I need a new impeller, too?

Kent talks in his video about the coke/carbon breaking free and chewing up the impeller. But what is not talked about (or what I can't find) is the amount of damage that constitutes the need for a new impeller.

Attached is a picture my current impeller. I hit it with a wire-wheel and brake cleaner to get rid of the exhaust build-up, and this is what i'm left with. It is simply the most-outboard sections that are damaged.

All other portions of the blades seem fine. There does not seem to be much scoring or other damage to the shaft.

Can someone tell me if I need a new impeller?

My guess is that the bad blades translate to worse performance ... but I'm certain that any work I'm doing will only improve the performance! Just curious if the extra $120-ish is worth it.


If so, what type/size should I order ... and from where? Kent is out of stock, and there seem to be plenty of other places, I'm just not sure what I should be asking for.

Many thanks!
Geoff

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If the Turbine Wheel or the Compressor Wheel lost any Metal they would need to be rebalanced before they can be reused.

In the Fuel Injection Shop where I used to work something line 30 years ago We did a lot of T and VT50 Cummins Turbo Chargers and a lot of T18A40s that the Detroit Diesel used.

We did do some grinding and re-balancing (we sent them out to be balanced) on damaged Turbine and Compressor Wheels and re-used them. So that is possible. But, I had My Boss to tell Me if something was marginal strength wise or not.
One of the things that was looked at is if the damage went into the web on the Back of the Wheel; yours has a chip out of that area on one Fin.

You also need to check the Groove on the Turbine Wheel that the Piston Ring Seal rides in. If there is a step worn into the Groove considering the other damage the Turbine wheel is up for replacement.
If you take that Wheel to a Balancer He will likely be able to tell you if it is re-usable.

I would think that were the chip came off you need to round off that square edge or it will also crack off later.

If both Wheels are damaged you are better of finding used Turbo in better condition to rebuild.

The cost of a new Turbine Wheel may be close to or exceed the cost of a Cartridge Assembly.
There are places that repair the Damage to Turbine Wheels; tip damage as you show and also the Shaft and Seal Ring area but I know of none that are Retail; they sell to the re-builders who supply them with a bunch of Cores (not all Cores are rebuildable).

Unlike a Truck that spends most if the time pulling a heavy load and stressing all of the parts on the Truck your Turbo does not pull that type of load so you might get away with reusing the Turbine Wheel if it was rebalanced.

The Guy that does the Balancing will know better if it can be reused. However, that place where the chunk cam off; the squared edge needs to be rounded off a little or it might crack off later.

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84 300D, 82 Volvo 244Gl Diesel

i just bought a low mileage turbo off ebay... the turbine was clean and no chips... total cost was 130 bucks. If you need a new turbine maybe i can help with my old one. I broke the housing for the oil supply tube so that peice is no good but the turbine is still good...

Thanks ibenz.
that may be a great solution.
i'll email or im based on your signature?!

back to the above from 911 ...
what is the true penalty for out-of-balance turbo?
does that simply make your bushing wear out faster (more wobble?)
i can only the thing has been out-of-balance for 10's or 100's of thousands of miles already ...

once i get this questions solved, here is my next:
as any one used 'staggered' seals? i've seen them applied to other turbos ... but haven't seen them offered for the T3s ... at least explicitly for the MB.

thanks.
geoff

it depends what level "out-of-balance"

low(er) power,oil consumption,clouds of smoke.....and finally turbo and engine destruction



cheers
.

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w126 500SEC gen II euro, powered by OM617 turbo stolen from 84 300SD 2.88 diff,EGR blinded
next wish/project: w114 coupe OM603 powered

I blew a turbo one time on a dump truck hauling a load of hot asphault up a steep road. you ain`t seen smoke till you blow a turbo, it burried the highway in white smoke.

It must have sucked oil past the seal into the exhaust side, then burned hotter and hotter till it melted a hole in the cast iron housing. the turbo was gowing red as well as the down pipe, along with flames shooting out when I flipped the hood open.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

Okay ... I get the potential failure modes ... for sure.
It seems like cleaning up the turbo would help ...even if i just put every piece back in as-is.

That said, I think think ibenz is going to help me out with some lightly-used parts.

Back to my other question: does anyone know if staggered rings will help prevent oil blow-by ... which would lead to carbon/coke on either side of the turbo?

thanks
geoff

I actually think you know the Answer to that. Your Turbo has not spent the whole 2K+ miles out of balance.
I don't think there are very many Members who would re-use the Trubine Wheel as is.

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84 300D, 82 Volvo 244Gl Diesel

I saw one at the pick n pull for $40. It didn't have play in the shaft or apparent chips in the wheel. There are many 617s around here.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

@D911: that is exactly the answer I was lookig for. Thanks.
@Junkman: I don't know of any good scrap yards here in Bend Oregon. If I did, I'd definitely take it as an opportunity to show my 5 year old girl how to get the best goods.

Thanks for all the help on the turbo.

I'll try this question once more: thoughts on stepped dynamic rings??


Next on my list: the massive oil leak on the front/left/American-passenger/non-injector-pump side of the engine.