did you disconnect the battery ground before welding?

 

I didn't use command to lock tcc. it never lost lockup during that drive. I parked it soon after it started slipping. previously the order of events are: trans works as it should, gets warmed up, first slip occurs on a down shift acceleration event, repeatable, eventually leads to lockup slipping.

this was only one drive. I haven't drove it far enough to start slipping tcc again as I don't want to get stranded or do more damage.

terravast4

I did not disconnect battery. I've debated it in my mind plenty of times but muffler shops also don't do it. I did it the first few times I've welded but not this time.


also, does anyone have a config file that I can use to monitor tcc slip and tcc duty cycle? my config setup skills are very low.

 

Could be your 3/4 clutches slipping. Try turning lock up off in the scanner and see what happens when you beat on it.

How does the fluid look and smell?

Chris

 

ok will do. fluid looks good; transparent red, didn't smell it so i'll do that too.

 

I found out trying to look up the guy I bought it from BMR racing transmissions that it looks like he shut down shop. so much for my 3 year warranty. lesson learned i'll stick with local reputable shops going forward.

 

ok, fluid smelled fine. I drained fluid dropped pan replaced filter added new fluid and test drove.

old fluid had some material in it but not bad and magnet had some material on it but again not bad. I was going to swap in my old epc solenoid from the trans this replaced but I found out this one is newer 03+ electronics.

on the test drive everything seemed better but not great. I searched tune repository and used stock 04 trans tunes to make some adjustments in mine, mostly force motor chart. I received this truck modified so I've never started from a stock tune. again after my adjustments things are getting better.

what I have now after a lot of driving is shifting seems good and I don't really see any slipping except for one scenario. driving 70mph on highway my tcc/or 4th gear isn't holding well at all in normal mode. if I push my tow/haul button its grabbing good.

using on/off controls I unlocked tcc, locked in 3rd, locked in 4th, locked tcc and with me making commands everything seems to hold as it should when I push it.

maybe my line pressure is low or something is telling it to drop out? i'll attach my current tune for anybody to check over. look specifically as to why it will hold while tow/haul(performance) mode is engaged maybe?

 

mods.. move to tuning section if needed please...

ok, I got more logging in today and have narrowed down the event much better. it appears I only get a slip after cruising for a distance at highway speeds. it appears if I have light or 0% throttle for a given distance and coast down to 60mph or lower then reapply throttle I see slip (engine rpm exceeding trans input shaft speed). once this occurs lift the throttle and it grabs or give more throttle and it continues to slip worse or grab if throttle is light enough. if my converter is locked and engine rpm exceeds trans input shaft speed that is slip on lockup clutch correct?

in this log you can see around 36:40 where I held throttle just enough that it kept trying to grab but keeps slipping for a good amount.

there were several other spots I got big slips in the file you can see if you go through it.

I found a new weird issue too that happened a few times while driving around. you can see one at 33:08. going 70mph in this event some how my trans input speed actually dropped to 0rpm when I lifted throttle.

forgot to add my config file its further up in this thread though.

 

update, for quick easy attempt thinking maybe Im bypassing fluid or converter is bad I put a new converter in and replaced transmission input shaft oring. that wasn't the problem. time to get this thing to a shop.