my C6 destroyed my engine

My C6 trans destroyed my engine. Installed rebuilt 351C and rebuilt C6 w/ a shift kit and 10,000 miles later had trouble w / timing chain wear and while removing the timing chain noticed a lot of motion free play in the crank. Thinking something was wrong w/ my thrust bearing I dropped the oil pan and removed the #3 main cap and to my unpleasant surprise there was a deep grove in the flat part of the crank journal which rubs against the thrust bearing at the rear of the bearing . the rear part of the bearing was also severely worn down. I could not just replace the bearing the entire crank was toast. Wtf! One of my worst freaking days. Many conversations later w/ many car guys it became apparent there was abnormal pressure on the back of the crank from the TC causing premature thrust bearing wear. What the hell would cause that. Spoke to an auto trans specialist at the local ford dealership and he said yes if there is a problem in the C6 with the hydraulic pressure it can cause the TC to push constantly on the back of the crank. Apparently , the TC pushes on the back of the crank only w/ hard acceleration and backs off then throttle is released. Don’t know if maybe improper installation of the aftermarket shift kit could cause this . any way I installed a different C6 so hopefully this will not happen again.

Wow that sucks! Good luck with the new trans.

When you install the trans you need to check that there is freeplay between the converter and flexplate. You need about 3/16".

could have also been TC not 100% seated correctly

the C6 is a real pain in getting the TC 100% down into the pump and keyed you have to go left and right installing the TC while pushing it in like a safe combination to get the TC all the way in. i had this issue where my TC was not 100% seated and caused all kinds of issues.

but i'm glad the last rebuild i did on my C6 i opted not to install a shift kit.

When you install the trans you need to check that there is freeplay between the converter and flexplate. You need about 3/16".

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+1

Seen the results of that mistake and it is very similar to yours....

could have also been TC not 100% seated correctly

the C6 is a real pain in getting the TC 100% down into the pump and keyed you have to go left and right installing the TC while pushing it in like a safe combination to get the TC all the way in. i had this issue where my TC was not 100% seated and caused all kinds of issues.

but i'm glad the last rebuild i did on my C6 i opted not to install a shift kit.

Click to expand...

Did the same thing my first trans swap. Luckily as soon as I started the car the toque converter pretty much blew the front seal of the trans pump and marred up the collar on the torque converter. Ended up having to pull the trans and have the local trans shop weld a new collar on the converter.

I always spin the converter and number of times until it drops in the rear pump. You can feel it lock in.

I'm not familiar with 'Free play" between flex plate and torque converter. The converter gets bolted directly to the flex plate.

I'm not familiar with 'Free play" between flex plate and torque converter. The converter gets bolted directly to the flex plate.

They are saying after the bell is married to the engine block there should be a bit of play between the TC and the plate so the TC IS NOT pushing on the crank.

Paul

I'm not familiar with 'Free play" between flex plate and torque converter. The converter gets bolted directly to the flex plate.

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They are saying after the bell is married to the engine block there should be a bit of play between the TC and the plate so the TC IS NOT pushing on the crank.

Paul

Before you put the torque converter nuts on, you should be able to move the torque converter back and forth about 3/16" between the flexplate and the pump face. In other words when you tighten the nuts you should be drawing up the converter to meet the flexplate. If there is no free play or end play or whatever you want to call it, you are either going to damage the transmission pump, or be putting pressure on the crank which leads to this type of thrust bearing failure.

When I was running an FMX behind my 460, I had to use two block plates to obtain any amount of free play. I didn't have 3/16" but I had enough that after 5 years of use there was no thrust bearing or trans pump issues.

I'm not familiar with 'Free play" between flex plate and torque converter. The converter gets bolted directly to the flex plate.

Click to expand...

They are saying after the bell is married to the engine block there should be a bit of play between the TC and the plate so the TC IS NOT pushing on the crank.

Paul

Click to expand...

Before you put the torque converter nuts on, you should be able to move the torque converter back and forth about 3/16" between the flexplate and the pump face. In other words when you tighten the nuts you should be drawing up the converter to meet the flexplate. If there is no free play or end play or whatever you want to call it, you are either going to damage the transmission pump, or be putting pressure on the crank which leads to this type of thrust bearing failure.

When I was running an FMX behind my 460, I had to use two block plates to obtain any amount of free play. I didn't have 3/16" but I had enough that after 5 years of use there was no thrust bearing or trans pump issues.

Yes this is correct I misunderstood.