I would appreciate any ideas or thoughts on what could be going on here?
I installed a new torque converter (Hemi) and now I am getting harsh shifting, slippage, and intermittent loss of lockup.
The harsh shifting seems to be only when it is cold after initial startup. (I am in Ontario Canada) I had a big AHA and jump out of bed moment on that one. I broke one of the cooler line connections at the factory cooler, so no big deal I wanted to put in a big aftermarket one anyway. So I no longer have fluid running alongside the coolant,,which I think helps to warm it up as the engine temp rises? So that might explain my harsh shifts when it is cold? However I am also getting intermittent loss of lockup that isn't temperature related. I suppose it's possible that I got a bad TC, but obviously I want to make sue I am not missing or overlooking something here. the loss of lockup is usually overcome with a shutdown and restart. but not always. It also throws a CEL, which makes sense. With a new TC does it have to be reflashed at the dealer? Below is what I am getting for codes.
P0700 - Transmission Control System (MIL Request)
P0734 - Gear 4 Incorrect Ratio
Is there a ground strap at one of the upper bellhousing bolts that I possibly missed and is making an intermittent connection. I dont remember seeing one, but I have on other transmissions.
I have never had to get a flash done from just replacing a TC before?

Thanks guys.

Check the fluid level with the engine idling in N.
Is it at the full hot mark? If not, add more fluid until its above the full hot mark.

Did you replace the transmission pump along with the TC?
What you describe sounds like the common fluid drainback problem. Easy solution is to let the engine idle in N for a minute before putting into R or D.

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No I didn't replace the pump, only the TC due to complete loss of engagement.

Hmm,, I have been checking the fluid level with it in Park, the stick says to check in Park. I did think that odd,, but Everything is different on todays cars. Heck I am just glad here even is a stick to check it, right?

I will let it idle in Neutral for a while before heading out in the morning. Also check the fluid level once warmed up.

Any thoughts on the lockup cutting out?

And thank you!