BuckNasty92

Hey guys. Hoping I can get some opinions, leads or answers on my 4L80e swap. 4L80 mods were an HD2 Kit without pressure relief mod, seal kit and new filter. So the transmission is in and I've been driving and have gone about 200 miles. All is well with gear changes, shifts are very positive feeling and it runs great on the highway.

I'm getting the issue of no lock up which seems to be a common issue. Once in a blue moon it locks up and stays locked up until I let off throttle (which I understand is normal with the 4l80 segment swap and is a part of the factory tune). I've been reading forums and posts about this but haven't turned up any results. So here's the basics of what I know:

-HPTuners shows the PCM is commanding lock up and shows to going through the normal TCC modes

-Could be just me but it seems more able to lock up when trans temps are on the cooler side (Normally runs 114 to 140 depending on outside temps)

-I tried using a switch with a light to manually ground the TCC wire (Pin S) and when on the light illuminates so I know it is getting power but had limited results (Locked up once and held until I turned off the switch when I coming to a stop)

-Converter is the original converter which came with the 4L80e. I was waiting to make sure that the trans runs good before ordering a Circle D 3200 with lock up

-When manually commanding lock up in HPT with truck off, I can audibly here the TCC solenoid operating

-Fluid levels are correct when warmed up

-All gears work well and no code (other than the before mentioned p1870 Trans Component Slippage from converter still unlocked when PCM commands locked)

If anyone has had a previous experience with this, have any suggestions of where I should look from where I am now or has links to threads that I may have missed, I appreciate all input, criticism and praise. Thank you.

madmann26

iTrader: (7)

If the tune is right, it should lockup at the desired mph.

For me, that’s in 4th at 51mph.

BuckNasty92

My tune is showing it's set to lockup at 43 mph in 4th gear. I'm at work currently so I may raise the MPH for my ride home and see if that changes anything.

Thanks for the reply madmann26

BuckNasty92

I think I might be narrowing something down here. I took a datalog on my way home last night and something that caught my eye was the top line of my charts. I have the drivetrain RPM's listed from engine to output so I could visualize where RPM's are changing.



The first thing I noticed is the constant converter slip (lack of lock up that I expected) but the engine RPM is lower than the Trans Input Speed. I'm assuming this is the torque multiplication coming from the converter but would like someone to confirm this for me as this is my first time actually seeing this in a data log.

The second and what has me a little more concerned is that the input and output speeds are the same which is indicative of being in 3rd gear BUT the computer has commanded 4th, I swear I can feel the truck shift into 4th and shows the correct shift time in the Latest 3-4 shift time. It also shows a 3-4 Shift Time Error of 6.2 which I believe is the maximum number shown but that's just something I read. Not confirmed with anyone else. I have read before that the 3-4 clutches are somehow tied in with the converter but, again, I haven't confirmed this either but I'm not sure if I'm missing something here or not.

I'm starting to wonder if I removed or left a check ball that didn't need to be when I did my HD-2 kit so I'll probably be revisiting my transgo instructions and ATSG.

I appeciate any input and thanks for reading!

madmann26

iTrader: (7)

I’m pretty certain that torque multiplication only happens in 1st on the initial takeoff for a short period.

BuckNasty92

That’s what I thought but I didn’t know since the truck is running through the fluid coupling instead of the lock up clutch.

Any ideas on the the trans input and output rpms being matched in 4th?

BuckNasty92

Attaching current tune and data log

madmann26

iTrader: (7)

TCC Duty Cycle

Set the max to 100, min to 90.

Report back.

BuckNasty92

Adjusted to the above parameters with no luck

Computer is still commanding the lock up so I’m starting to think this is a mechanical issue and not a tune issue. Given that it’s locked up once before, I can hear the solenoid activating and it’s not even showing a slight drop in RPM like it’s attempting to atleast, I’m leaning towards the PWM or maybe a worn converter clutch.

BuckNasty92

So I took my multimeter and checked out the manually grounded switch that attaches to Pin S. The light I was running in the circuit was causing it to drop 2 volts. Ditched the light and went directly through the switch and now I’m getting full voltage grounded out. Before, the wires wouldn’t even spark when touched together and now they do. I can now hear the solenoid activating when using the switch.

With that being said I took it for a drive and still no lock up even with the manual switch in the on position. So I’m thinking what I’ll probably do is go ahead and drop the pan, get a new harness, TCC solenoid, order my converter and a new a new o-ring for the new input shaft. I would think that would cover all the bases and keep me from dropping the pan multiple times and wasting a lot of money on trans fluid in the long run