About 1200 miles ago I put in an aftermarket torque converter and shift kit (both are good name brands, not listed to keep this from becoming a product bashing session) and life was good. Today the truck started acting funny. When down shifting in to second (anything above 40mph) the truck will buck a couple of times then downshift. Also when stepping down on it at 60-80, the truck is sluggish then something engages and off we go. I highly suspect the torque converter is at fault. The reason I say this is because a hard launch and run up through the gears shows no issue. The problem only seems to surface when the converter is locked. Any ideas?

quote:

I highly suspect the torque converter is at fault.

Yer probably right.

Not so sure now. I decided to take it out this morning and give it a proper whipping and see if something wanted to break and speed up the daignostic process, no joy. (Somebody wants a big boy tranny.)Instead, I started to suspect a pressure problem. Went to the shop and removed the shift kit resistor and still had the same result. After driving a good deal it became obvious that the only time there is not an issue is at WOT from a standing start. Under normal/spirited acceleration the truck will buck/surge once on the up shift to second also. Not sure which direction to go. Never was a tranny man.

No codes? or TPS light?, and what year truck, what sized stall and stall speed, and im almost pretty sure you put in the TransGo, they are the only ones that make aftermarket shift kits for the 45/545RFE, if you just RECENTLY put in the kit, it is naturally going to do this because it has to learn the new shift schedules, especially if you put the stall along with this, you would definately notice if it was the Actual TC itself, but you could also have problems in the valvebody, Switch valve could be sticking, dirty oil, did you pull the battery cables to reset the TCM and PCM after the shift kit? It took my shift kit about 200miles to settle down completely now its just firm, but in the mournings whie the oil was cold was the worst and most harsh symptoms, it would buck, and bang through 2-3 lol

let me know and ill whip out the books

Converter and shift kit went in at the same time. The truck did fine for about 1200 miles after the install. This problem just popped up yesterday. The truck is an 05 and I have reset the computer and also tried retuning with Superchips. The result is the same no matter the tune. You are right, the shift kit is a TransGo and the converter is an Edge billet Hemiverter, 2400 stall. Went ahead and dropped the valve body today and checked all of the accumulators. Everything appears fine. I also changed the filters again while I was in there. Still had the same problem on the test drive.

you could even have an engine problem as well, is the converter stalling up like it should?, I mean it could be the converter, maybe a turbine shaft got hurt during the install, o-ring, do you have a pressure gauge? Thats the best bet to diagnose a converter problem, or maybe its the TCC switch valve.

Engine is good to go. The converter stalls just like it should. The truck launches great. I do not have a pressure gauge and honestly would not know where to start. The problem only shows up when shifting or when the converter clutch is kicked out.

sounds like what happens when the TCC switch valve is sticking! i dont know of any immediate problem, i know there is problems with 2nd prime crapping out on the RFEs, but yours does sometimes upshifting too, so i would diagnose for a TCC or switch valve problem.

Well, it may very well be electronic. On the way home from work today it decided to behave.

sounds exactly like a switch valve problem, might otta try getting the oil nice and warm, and just doing a fluid change, you can clean the valvebody, but you have to take it apart and remove the valves, if you are up for it, its not that hard if you torque everything back together when you are done.

I would have to come up with some sort of a maunal before I would think about doing that. The last time I had a valve body apart was in the late 80's and a TH350. Isn't the TCC switch valve in the front pump?

yes the TCC switch valve is on the oil pump, but i didnt figure you would want to take down the transmission so i figured clean everything the best you can, including the solenoid switch valve inside the valvebody.

Well, it's still going. I played a bit with it today and found that if you mash on it and manually pull in to second that it sticks in third and surges. If you still think it is a switch valve problem, I may change it out. Won a new one for next to nothing. I was going to save it and use it with a Stage 2 VB in the near future.

quote:

I played a bit with it today

What a coincidence.