tt9714

While the KKK turbo is out of my '86 951, I tried to determine the condition of the bearing.

According to the factory manuals, the specifications are:
Maximum end (axial) play: 0.16 mm
Maximum radial play: 0.42 mm

I took hold of the "cold" side shaft to get a feeling for the bearing play. I don't have a dial indicator, so I cannot provide a quantitative analysis. However, I do hear a clicking sound when I check for radial play. The shaft and entire turbine visibly moves about 0.6-0.8 mm in the housing. I don't believe that it touches the housing around the outer circumference, but there really isn't much clearance here. As for axial play, not too much here so maybe within the 0.16 mm spec.

My engine was consuming a lot of oil (~1 quart in 1500 miles) and I'm thinking that most of it was going through the turbo. My intake manifold & throttle body were pretty well covered with oil.

I'm not in a position to upgrade the turbo at this point. Would it be cost effective to have the stock turbo rebuilt, or just save my $$ for a new & larger unit?

Any issues with reinstalling the unit in my car? I'm assuming that the unit will continue to wear with age. Is there a definite failure mechanism, or will it just continue to leak more oil?

Also, when I try to spin the turbine by hand, it barely makes one complete revolution before stopping. Should this be much more freely spinning, or does the oil supply need to be flowing to get the resistance down on the bearing?

Luke

I compared the play in my new SFR turbo to my 70k mile k26/6. They honestly feel about the same. I wonder if it has to wear in? I hear a clicking noice on the "hot" side of the SFR. I beleive the pics in the fact. ws man show them testing bearing play at the hot side. <img src="confused.gif" border="0">

tt9714

Lukesilver95186,
When you say:

[quote]I compared the play in my new SFR turbo to my 70k mile k26/6. They honestly feel about the same. <hr></blockquote>

What exactly do you mean? In other words, did you feel the radial play in both units like mine? BTW, my turbo has 142,000 miles on it!!

Also, I noted the same thing about the factory manuals where it says:

[quote]Radial play is measured only on the turbine [exhaust] side.<hr></blockquote>

Why can't the radial bearing play be measured on the cold side?

951and944S

tt9714,

Do you know the history of the car..?
Does the Blue and silver tag say '86.?
Possible the turbo was replaced somewhere along the life of the car.
Oil consumption of 1 quart isn't that uncommon.

There are not really bearings in the KKK. They call them bearings, but they are actually bronze or brass bushings. A constant supply of oil to them keeps them healthy.
The sealing area, wher the locking rings make a seal on the inside diameter of the hot and cold side is probably full of coked oil.
These rings have a step in them to allow them to lock, they work by expansion, because they have a pretension so to speak. When the turbo is new, these locks are about half deep in their travel, then through time and mileage, coke (burnt oil) fills the gap and as the ring or inside diameter wears, they can't adjust for size as intended, because the designed, lock is frozen with coke.

I know this is confusing, but I'm doing my best, its one of those things you have to see to understand.
One more note, there are no real seals in these turbo's or any for that matter. They have sealing rings, but basicly pressure from either side keeps the oil in..

If you need a pic to explain above, email me,
944t@bellsouth.net

951and944S

Get a dial gauge, if your this concerned.

[quote] Any issues with reinstalling the unit in my car? I'm assuming that the unit will continue to wear with age. Is there a definite failure mechanism, or will it just continue to leak more oil? <hr></blockquote>

If, it fails you'll know it, it will not remarkably quit leaking, more than likely a noise will be heard when the rotor begins to contact the inlet housing, at which time, you'll have to upgrade, since rebuilding will require a good core, but upgrading will need the whole turbo for core deposit, but only requires reusing of the hotside.

If you feel safe reinstalling it, change all exhaust sealing ring while you have the oportunity, to avoid an exhaust leak, and by all means DO clean out the intercooler. You can regain some lost performance, since it has oil in it also..

tt9714

951and944S,
Thanks for your quick and informative replies. I checked the mfg. plate on the turbo and it looks original:
[quote]K26; 86 914 0205; 5326 970 6720<hr></blockquote>

I did find this parts diagram for the KKK turbos (courtesy of Majestic TurboChargers <a href="http://www.majesticturbo.com" target="_blank">www.majesticturbo.com</a>)



Can you tell me which numbers on the diagram correspond to the "sealing rings" that you describe?

Any recommendations out there on who can do a good job rebuilding the KKK turbos? I checked out Majestic Turbo's website, and I would consider them. What's a reasonable fee to charge for this service?

One other thing, what's the best way to clean out the intercooler? Can this be done while it is still in the car?

Thanks,
-MDW

951and944S

tt, Do you see the darkened groove on the stator..? That's where the ring for the exhaust side goes, so I assume # 14 would be the rings, I'm kinda fuzzy on it, but I have several, in disassemble condition but unhurt in any way, if any parts will helpyou out.
BTW, try Turbo City, i think they have a site, I have their catalog and # at my shop, could get it for you tomorrow, if i remember.
They sell a center section that's renewed. The secret to turbo longevity is balance, VSR, is the type really required to do a good job. You'll notice some circular grind marks on the underside of the inlet rotor, if you pull the cold side off, which BTW can be done along with the hotside, without harming anything..
Do you understand my exp. on the rings locking type..?

Cheers

951and944S

BTW turbo city also has a DIY rebuild kit, but you have to develope a real accurate way to realign the cold rotor for balance sake....
#'s 1 are the bushings, after further thought, I guess if a rod bearing can be called a bearing these can too...!

One last thought, check the classified section, there are constant ugraders, that sell little used turbos at resonable priced. I'd say you could get a K27#8 or K26#8 for around $300.00 with few miles..
Whatever you do, don't go the non water cooled type. I just can't see how they last as long.
Re: cleaning intercooler. Uh, tough one on the car, I'd say no, you'll understand, when you have it off for cleaning. The design does not drain well, even off the car, if tipped on end. Sort of like draining a torque converter if you have any experience with those.
Mineral spirits, Varsol, works good, then a cleaner like Super Clean to follow, flush with water very thoroughly and allow to air dry.
You can find the removal procedure at SFR's site.

Luke

I would imagine you meausure radial play only at the hot side for two reasons.

1. heat cycling is much more pronounced there.
2. the majority of the force happens on that end. If a rod is connected at two points and the first flexes to an angle. the further point will only flex to a fraction of that angle (depending on the length of the shaft.)

This is just my Idea of it though?


btw. Actually I just wanted to say "length of shaft" in a post.