tiresmokinV8

iTrader: (6)

'10 e67 with Colorado base tune and t42 tcm. TCM was tuned by Currentperformance as was the wiring. Problem is reverse just drags the engine down to where I cant hold the brakes while in reverse or it will stall almost like the convertor is locked or something. Same thing happens if Im cruising and runs through the gears then come to a stop in d4. itll drag the engine down to about 400 rpms for a few seconds then itll release and idle like normal. Not sure why its doing this. Fluid seems to be the correct level with engine running in park. Trans is new 4l80e stage 2 full auto from Jakes, convertor is CircleD 3600.

tiresmokinV8

iTrader: (6)

Thinking this might be a convertor issue since at idle the convertor shouldnt be sending power to the transmission anyways and the transmission doesnt have anyway to unlock while in gear only neutral so somehow the convertor is still sending power to the input shaft of the transmission at low rpms.

Jake's Performance

iTrader: (2)

Unhook the main connector to the trans and see if the issue goes away. If so, you have a wiring/tuning issue. If not you have a converter issue.

tiresmokinV8

iTrader: (6)

Thanks Jake, will do. Also thanks for the prompt email replies.
Rick Zisk

Circle-D

iTrader: (21)

Let us know what you find out....

And how does the lock up feel when it applies in high gear?

Chris

tiresmokinV8

iTrader: (6)

Thats another thing, Ive only cruised once at a speed higher then 55mph (have 3rd applied zero'd out and 4th applied at 52mph) and it never locked. Didnt have the scanner on so I couldnt actually see if it was commanding the lockup to activate and couldnt manually activate it. Everything else has been slowing down and accelerating and only up to maybe 45mph. Ive only put maybe 3 miles on it since I dont want to hurt anything. Ill unplug it and try it out. What does unplugging it still allow to function? reverse and 2nd?

Circle-D

iTrader: (21)

It probably is not warm enough yet to lock up. I don't think you will cause any damage to put some miles on it and test it.

One more idea is converter clearance. What was your converter spacing? We have seen to little space possibly cause cooler flow issues, which would cause the clutch to drag at idle.

Chris

Jake's Performance

iTrader: (2)

As Chris said,
It isn't going to hurt it to drive it without lockup for test driving, diagnosis purposes.

We have also seen the same deal with converter spacing causing lockup dragging.

tiresmokinV8

iTrader: (6)

Too little spacing between convertor and flexplate? I added washers to take up the gap between convertor and flexplate. Brought it down to 1/8" gap. So would having the convertor in the trans too much cause possible lockup issue or too far out??

Jake's Performance

iTrader: (2)

In the trans too deep.

Circle-D

iTrader: (21)

Correct, in the trans to deep. It can restrict the return flow coming out of the converter back to transmission pump. And no flow through the converter can cause the clutches to drag. I suggest pulling the shims and see what happens.

Chris

tiresmokinV8

iTrader: (6)

Thanks you guys! Ill try that tomorrow and report my findings.

10droped

iTrader: (1)

This great customer service right here!!

91sonomast

Props to good companies. Please, don't become ******** in the future like some companies do.

tiresmokinV8

iTrader: (6)

Took the spacers out and pushed the convertor all the way into the transmission with spacers a 1/8" bit is very snug without spacers the 1/8" fits no problem and a 3/16" bit wont fit so it should be good without spacers. Bolted it all back up without spacers and took it for a spin. At first it backed out of the drive no problem stopped in reverse at the end of the drive no problem when around the block stopping 3 times and it idled fine. came to my drive put it in reverse and it lugs down the engine and stalls it out. start it up throw it in reverse real quick and give it gas to get it rolling backwards and drive in reverse up my drive come to a stop and it stalls out the engine again. Start it and try out drive and it idles in drive fine but really slams into drive try reverse and it slams into reverse and lugs down the engine again. So convertor was indeed in just a smidge too much but it still lugs at idle. Didn't seem to take as much effort though to get up to speed and maintain speed.

Circle-D

iTrader: (21)

Hmmm.... So it worked fine for a while, but then problem came back. Have you tried to disconnect the trans plug to see what happens? Also put some miles on it and see if you can get it to lock up, it will need to be plugged in for this. What flexplate are you running?

Chris

tiresmokinV8

iTrader: (6)

Im running a factory replacement with spacer.

Circle-D

iTrader: (21)

You have the 6 Lug 4L80, so that is correct. Try putting some miles on it and see what happens.

Chris

tiresmokinV8

iTrader: (6)

Unplugged it and drove it around. Once again ok for the first 5 mins then locks up in reverse. Plugged it back in and went for a drive. Convertor will lock up on its own but the fluid temp rises fast and keeps going up. I have a tru-cool 40k right in front of the radiator. got back to my garage and the trans temp was reading 220 through my hptuner scanner yet the cooler felt luke warm. Kept lugging at idle in drive once I drove a few miles.

Jake's Performance

iTrader: (2)

Check your grounds, the high fluid temp reading and not actually being hot indicates a possible electrical problem.
Do you have an IR temp gun to check temps?