karmadhi

Hi guys wanted to share our experience and maybe get a few opinions.

6766 journal bearing precision T4 divided housing 1.15.

Around 500 miles in total on the turbo and during inspection we found comp wheel was touching the cover. Took the turbo appart and the thrust bearing is toast resulting in loads of side play. Turbine wheel has not made any contact.

All in all we made about 30 dyno pulls and around 10 runs at the strip. Car made 750whp on a 3 liter motor, tubular manifold, 4 inch exhaust.

Now spoke to Precision, they inspect the turbo and come up with the reason for this failure being high backpressure??? Previous turbo we ran on this car was a 66mm borg warner, no issues at all, same setup T4 divided large AR.

I know these precision turbos are in the lower price range in the market but hell man this is just shocking, car never lost oil pressure, turbo filter in place, adequate 4an lines so there was absolutely no reason for any other causes of failure.

I have read multiple thrust bearing failure stories, some say the reason is the steel thrust bearings they use overheat, the brass ones are meant to be better at heat dissipation?

I hope they will fix this for us as its a few weeks out of warranty now but I am seriously re-considering ever purchasing a precision product or recommending them to anyone.

$MIKE$

iTrader: (13)

Well first off sorry you choose a Pte.
My turbo sat there for 3 months untill they found time to tell me it would be like $650 to rebuild. This coupled with a epic failure rate makes its easy to see why to not choose Pte.
Lots of high dollar race teams run Pte's so us little guys will buy there shitty units. I can only conclude they have a pallet of bnib Pte turbos to change out every event!! 💵💵💩

So I think what we have here is another case of a less than dependable unit crapping and Pte once again trying to pass the buck off to contaminated oil or some other bull **** reason they come up with. I sure they have tons of laughs everyday in the office.

Now you are in the position that's its gonna be cheaper to just take the gamble on another Pte rebuild than fork over 2000 for a good ball bearing unit. Tough choice man
You might wanna give STC a pm and see what type of unit he can get you into.
Just my .02 good luck I've been though a couple diff turbos and its never fun.

karmadhi

Oh and during tear up we found that the thrust plate did not have any bolts holding it down just the 2 guiding clips. Found this strange, PTE tech said the new cea turbos dont have bolts holding this thrust bearing down hmmmmmm

NotARaCist

iTrader: (1)

Precision. There's your problem.

mar778c

iTrader: (1)

OP,

What is the maximum boost pressure this turbo has seen?

karmadhi

25psi

wantboost

iTrader: (2)

There's no way you'd have high backpressure with a turbine wheel and housing that big on a small displacement motor. Sounds like typical precision not wanting to admit a fault in design.

I don't know why precision still uses a steel thrust bearing retainer. It was proven years ago that the steel collars retain high levels of heat causing the thrust bearing to overheat and fail.

There's a reason every other company uses brass collars. They conduct heat easier. Notice you rarely see a Garrett unit with a 500 mile thrust bearing failure?

It's also odd they don't positively retain the collar. There's a reason everyone else uses bolts and why the collar has bolt holes in it.

Do the collar and bearing show any signs of excess heat?

I know turbolab offers a brass thrust collar for precision turbos. They also use bolts instead of clips.

wantboost

iTrader: (2)

Also a lot of people have had the billet wheels flex and deform around the hub and ends of the blades on precision turbos at high boost levels. It causes the wheel to touch the housing and can result in breaking the thrust bearing.

mar778c

iTrader: (1)

That pressure is fine.

One thing I noticed, where it the retaining clip for the compressor side journal bearing? Maybe, it is the angle of the pic not showning?

karmadhi

the clip was there but I removed it when taking it appart.
I have a couple of other precision turbos and looks like Im gonna tear them down and install a brass thrust bearing.

karmadhi

Anyone know what side play journal bearings should have when cold?

wantboost

iTrader: (2)

Only a few thousandths