hey all I am stumped. I am doing a 4l80 swap and it wont work so I need some help diagnosing. I have found a second tune with my same os and am going to try the segment swap again in case the first one didnt go correctly. I am also looking to find what else I can diagnose. on the wiring I swapped the wire on the U into the S position and have ISS in my scans.
what seems to be happening is the transmission starts out in first then immediatly shifts to second then even third according to my log even when I command it to stay in first. The transmission seems very "loose" like it is in second. The converter is a 2500 stall. This is a Bowler trans but has sit covered and filled with fluid for a little while but is basically new.
what should I check? I have not checked for power or anything at the trans.

included is my tune if that helps.
thanks
Dave

 

Log calculated gear based off VSS signal. The truck can ask the trans to shift but it won't happen if you're having problems.

Low pressure kept me in 2nd, so maybe a pressure test will provide a clue.

 

I will log that tonight, here is a short one I did pulling back into my garage. I dont have the calculated gear but shows the "gear" it is in. It shows starting in first then quickly going to second.

 

I don't like the way the shift properties or the TCC setup look. It looks awful.

The quick shifting is the shift properties. It's shifting out of 1st at 10mph in one table, 5mph in another and 7mph in another.

The full throttle shift mph is also wrong. Just bad wrong. Other parameters (shift pressure, TCC duty cycle) need some work but I think your main problems are in the shifting tables.

 

Thanks Madmann26, I will work on those. I thought they were stock values so for now I left them to get it to work. I do see they should be higher. I wasnt concerned yet in the "performance" setting as far as I know mine will only be in normal mode I have not researched on allowing to go from one to the other.
I will pull a tune with better settings to compare. It just seemed like it was shifting even before these speeds however if my speedo is incorrect just a little it would make a difference. I think looking at the log above my speed is off as I was just in my driveway.
again thanks I will do some changes, anybody else have any thoughts?
Dave

 

It's common practice Dave to use the same values in all the part-throttle tables to alleviate the differences that could be seen.

If you want some help, let me know what the rear-end gear is and what size tire you are running and I will put something together in a spreadsheet for you and all you have to do is copy/paste.

 

See the attachment for an example of what it should look like.

 

I would love some help and can send you different files if you need. Obviously this truck is my toy, it has had a 4l60e that I think I wiped out the converter. A t56 that I spun the clutch. Now this one. But that has been over 11 years so not a bad record. This trans is completly built, the spec was for 1000 hp/tq, now I am no where near that but it was speced for my bosses car and he decided to use a manual so I got a chance at this one.
my tire size is 27.5 inches tall and currently have 4.11:1 rear gears. That was from the double overdrive in the T56.
I am thrashing to get this ready for cruisin the coast. So I am down to a week...
thanks a ton
Dave

 

got that.
do you have any input on the pressures or TCC tables you mentioned. This is a 2500 stall

 

Let's get it shifting right first.

See the attached file. Copy/paste the data and report back. It's setup to lock the converter clutch in 2-4 gears. If you only want it to lock-up in 4th, let me know.