I had a 4L60E built by a Carolina Performance Transmission. It is there Level 4 that has all the goodies...Upgraded Servos, 4L65 upgrades, etc... When I installed it, I went with a PY3600 at the same time. After less than 1500miles and 3 passes at track on Nittos, it has filled the pan with fibers. I have changed the filter about 300 miles ago and it worked good for a few weeks (200+/- miles and now is showing the same signs. Anytime I do a hard pull with it, it will not shift out of 2nd and when I let off the throttle and get back in it, it just slips. I have to pull over for about 5 mins and turn it off. After that it will pull enough to get home but slips. What could be the deal? The shop that built it went out of business, so that is not an option. Thanks!

 

I know this is not what you wanted to here but it sounds like the transmission is going bad .
does it do this when its cold ?? or only when the its hot? if the transmission slips only when hot
you may need to add a trans cooler
something else that you might want to try is have a shop pump out all the transmission fluid not just what is in the pan. something might be stuck in the valve body

 

Something is definitely coming apart in the transmission.

Frank

 

Who do you reccomend I send it to, to verify problem? I just spent several $$$$ on this and really do not want to double it.

 

Look at franks signature . pro race 4L60E $1400 " it ain't braggin if you can back it up "
you can have a local transmission shop check it out and if they tell you that it needs a rebuild
I would get in touch with frank...... I feel your pain I had this happen to me before and it sucks !!!!