I've got a ST 3500 and getting a ST 4000 soon. What exactly is the ST series and how does it differ from the other series? Also, why did they stop making it? I had heard somewhere that there were problems with the ST series but I'm not sure what they were supposed to be. Anyone help me with this?

I'm looking forward to putting in the 4000 after I get it cut and cleaned. Wondering how much of a difference it will make for daily driving. Both are 2.5 STR's. Unfortunately, I won't be getting track time with the 3500 so I can't compare the differences at the track. Thanks is advance.

 

they discontinued the ST line because they started using larger clutches. pretty much the SS line replaced the ST line

 

Right. It wasn't so much that there were big problems with the ST line, they just went to a different combination of pieces (clutches, stators) and the SS line was born. The ST line has the reputation of a good quality, reliable converter, and the difference between your 3500 and the 4000 will be like converters in any other series - SS, TCI, whatever - higher stall speed, a little looser, etc.

 

So when I send it in to be refreshed will they basically make it an SS series?

 

pretty much. they do not use the clutch or parts of the ST line anymore. at least thats what they told me when my ST3800 broke a converter foot. so i opted to buy a new SS4000

 

They quit making ST converters for F bodies because of chatter problems.
Kevlar clutches were replaced with carbon to fix them.
I know because I have a ST3000 that started chattering at 2k sitting out in my garage that I replaced with a SS3600.

 

I have had my ST3500 for a few years and has been in different cars with no problems at all . best 60' i got with it was 1.60 and went 11.62. Now going to send it in and get something bigger as I'm running a SS4400 and going 11.39 with a 1.52 60' thanks to my friend for letting borrowing it .