picked up a 4l60e and threw in a 2500 stall/servo. stock 5.3/4l60e been driving it to work and have about 100 highway miles on it lockup functions fine. when driving around 40-45mph at crusing speed (around 10% tps and around 1300-1500 rpms) it will constantly lock/unlock every 3-5 secs and fluctuate about 100 rpms . any more tps over 12% or speed (over 45) it will lockup and act fine. I can touch my brakes (tcc switch) it will remain unlocked fine. is possibly a tuning issue?

I read the stickeys but didnt see any with this particular issue since this works fine except for the speeds i listed

 

never has been tuned with stall just stock computer stock tune..thanks in advance guys!

 

I'm going to GUESS that it might require a tune.
"Maybe" the computer is "seeing" the new converter as slip vs the old stock (tighter) converter or something else and making it do that?
Like I said, it's a guess.

 

Yea I had seen that somewhere as long as you stayed under 3k you should be fine. But then the only complaints from people that have gone bigger without a tune is it going to limp mode or hitting the limiter before it shifts. Which mine does neither of those

 

Guess I'll drop it off with frost for a mail order tune... link dosent work for me but most of the people I see saying this say it's doing it all the time over 40mph. I log my on a edge insight and it's only during those %tps and speed. Didn't wanna spend money on the tune just yet since I wanted to pull the motor back out and do cam/springs etc. I just slapped it all togeather to make sure my donor motor,trans,cooling all worked but the trans didn't come with a converter so i stuck the acc 2500 in there