I am having a bit of trouble with the trans in my 02 1500HD
Per the previous owner - Its a new 4L80 with a shift kit a REVMAX 2600 stall converter, Tru-Cool 40k cooler

When the truck has sat overnight if I start the truck and shift to drive or reverse without waiting it will not move.
If I give it throttle it might move slowly but not much.

If I let it idle approx 30-60 seconds - then shift to drive or reverse - everything seems normal.

Fluid appears to be at the proper level - is there anything else I should check?

There are light fluid leaks front and rear

One last thing I might mention - My engine is heavily modded but still won't spin the tires. If I stand on it from a stop the rpm's go to approx 2600 and stay there until the truck gets moving. I'm just not currently impressed with the way it acts and I'm wondering if transmission troubles can be causing this.

 

its probably the converter, id change it out with a circle D/

 

Thanks for your input.
I just have to know what it is that tells you that?

I've never driven any vehicle with anything other than a stock converter so I am trying to figure out how to diagnose this.

 

I dout its the converter itself but the trans is letting the oil in the converter bleed back into the pan. Check the oil 30min after you shut it off then check it again the next morning (not running) and see if the oil level raises from setting overnight. Both my 80e did this sometimes, if it dont bother you I wouldn't worry about it. Also try reving it up to 4k once before dropping it into gear, should engage quickly then.

 

Yes, I agree the delayed engagement sounds like converter drainback. Which should not be the converters fault. Sonnax has a valve that is suppose to address it.

http://www.sonnax.com/system/announcement/34200-14K.pdf

The no tire spin just sounds like the stall is to tight.

Chris