[2018ZL1]

Got to a TNT on Saturday and ran a new PB but not without damaging the motor I am thinking!!! The MPH is way off so whatever happened it happened during the run! After I went thru the traps the car shutoff... I put it in neutral and was able to steer it off of the track. Tried to crank it over and it barely turned over once than nothing! got it home and removed the plugs and removed all of the belts... cant turn the motor over with a breaker bar on the crank! Next I am gonna drain the oil and cut open the filter and see what i can find! Been told by a few folks that over 900WHP some of these LT4's have crankshaft walk issues! Has anyone heard of this? I just had the transmission rebuilt and a new circle D converter installed so i was hoping something happened with that but it doesn't look like it so far!

[2018ZL1]

Worst case confirmed!!!

[laynlo15]

Did it bend the rod or bearing seized up on the crank. Man I have been there and know exactly how you feel. I broke the crank in a forged motor, it broke internally and the Lt1 broke 2 ring lands. Its just a bad feeling and I know your feeling the burn right now. Sorry for the damage it incurred. But it was a great pass.

[2018ZL1]

Originally Posted by laynlo15

Did it bend the rod or bearing seized up on the crank. Man I have been there and know exactly how you feel. I broke the crank in a forged motor, it broke internally and the Lt1 broke 2 ring lands. Its just a bad feeling and I know your feeling the burn right now. Sorry for the damage it incurred. But it was a great pass.

It really is a bad feeling! I was really hoping it wasnt something internal but that filter doesnt lie! Not sure exactly what happened yet... I will post when I do. Thanks! New PB was most def bitter sweet! I am addicted to making this car go faster so who knows what will come out the other end after this!

[KingLT1]

Solid pass!! My guess is Thrust bearing failure. That is the weak link in the LT4.

[2018ZL1]

Originally Posted by KingLT1

Solid pass!! My guess is Thrust bearing failure. That is the weak link in the LT4.

Thanks! It didnt hurt quite as much when i saw the slip! Thats what I am hearing as well about the crank walking.. that would certainly do it!

[Duramacr1]

Wow that’s moving . Sorry to hear about the motor .

[2018ZL1]

Originally Posted by Duramacr1

Wow that’s moving . Sorry to hear about the motor .

Thanks! Most def biter sweet!

[Joshinator99]

Originally Posted by KingLT1

Solid pass!! My guess is Thrust bearing failure. That is the weak link in the LT4.

I suspect this could have happened due to the torque converter installation. If they didn’t double check crank end play and the TC mounting tabs were a hair thicker than stock, you’re done.

[2018ZL1]

Originally Posted by Joshinator99

I suspect this could have happened due to the torque converter installation. If they didn’t double check crank end play and the TC mounting tabs were a hair thicker than stock, you’re done.

This is a possibility! I am probably going to take this thing apart myself so I can see for myself if it was dues to the converter! I did drive it quite a bit after the converter was installed and it didnt have any issues...

[laynlo15]

Those are well know for Oil Pump failure also and as King said fried bearings including the thrust bearing are very possible. Usually when the basically lock up like that its a rod bearing. A buddy of mine had to rod bearings lock up on the dyno. You could not turn it over.

[Joshinator99]

Originally Posted by 2018ZL1

This is a possibility! I am probably going to take this thing apart myself so I can see for myself if it was dues to the converter! I did drive it quite a bit after the converter was installed and it didnt have any issues...

Originally Posted by laynlo15

Those are well know for Oil Pump failure also and as King said fried bearings including the thrust bearing are very possible. Usually when the basically lock up like that its a rod bearing. A buddy of mine had to rod bearings lock up on the dyno. You could not turn it over.

The thrust bearing being fried would be a dead giveaway to the TC install being the issue. If it shoves against the flexplate it takes up your crank end play and pushes the crank against the thrust bearing. Just a matter of time at that point. The fact that a new TC just went in doesn’t seem like coincidence to me.

I’m not a gambling man, but… <pushes pile of chips to the center of the table>

[2018ZL1]

Originally Posted by Joshinator99

The thrust bearing being fried would be a dead giveaway to the TC install being the issue. If it shoves against the flexplate it takes up your crank end play and pushes the crank against the thrust bearing. Just a matter of time at that point. The fact that a new TC just went in doesn’t seem like coincidence to me.

I’m not a gambling man, but… <pushes pile of chips to the center of the table>

I am with ya here! Thats why I want to take a look at this myself! Any idea if you can drop the oil pan on this while its in the car?? I was looking at that last night on the lift and it looks like you can.

[2018ZL1]

Pulled the motor and dropped the pan... as you can see in this pic the Thrust bearing spun and I am guessing it covered the oil hole which in turn burnt the bearing on cylinder #3 and #4! Not sure what will be salvageable here! I am really surprised this thing didnt throw a rod out the side of the block! Had to drop the engine and tranny at the same time because I couldnt turn the motor over to get to the converter bolts...