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Donor trans is a 2000 4L80E from a 3500 Quad cab Chevy. It's installed in a 2002 Silverado RCSB with a 4.8 that originally ran a 4L60E.
Some background:
When I bought the trans used, the fluid came out nice and red and clean, minimal amount of sludge on the magnets. I installed a Transgo HD2 kit per the sloppy video and have it behind a Jake's 3200 street converter. When installing the converter I dumped a couple quarts of fluid in it. I made sure to seat the converter all the way in, but had to pull it forward to reach the stock 4.8 flexplate. I also had to elongate the holes on the stock flexplate to get it to match up to the converter.
Obviously I had to segment swap the tune, so I grabbed a 5.3/80E tune and used that to do the segment swap. The tune seemed to take it fine as it shows up as a 4L80E and reflects the 80E gear ratios. Also moved the pins around in the round connector and wired in a new pigtail to connect to the forward speed sensor (input).
I just fired the truck up for the first time today and it doesn't move in any gear. I dumped in 8 additional quarts before starting the truck and the fluid level doesn't move whether the truck is running or off. As a sanity check I pulled the pressure side of the cooler line at the cooler and have no fluid flow. I suppose I could pull that line at the trans to make sure it's not blocked, but it's a new ACDelco line so I can't imagine it's clogged.
Another hint may be that HPT Scanner shows it's always in 2nd gear regardless of where the selector is. The PRNDL indicator on the dash shows it going from Park down to 2nd just fine.
Pic just to have a laugh since I am pretty pissed at this thing right now
In terms of troubleshooting I am thinking the following:
Pump is not turning because converter isn't seated all the way? Despite being bolted up to the flexplate?
Should I unbolt the converter from the flexplate and seat it all the way in to measure converter pad to bellhousing flange distance?
Would incorrect wiring and or bad segment swap cause HPT Scanner to show trans being in 2nd all the time?
I am really hoping I don't have to pull the trans again as it was a bitch to get it in alone.
In case in matters the tune is attached. Thanks in advance as always .
Thanks for your reply. I think what I'm going to do in the morning is unbolt the converter from the flexplate and seat it all the way into the trans, then spin it and see if fluid comes out the cooler line. If that's the case then I need a spacer (which from reading now it looks like I do since I'm using a Pre-LS trans on an LS).
Still doesn't explain the Scanner saying it's in 2nd gear when it's actually in Park though...unless it's doing that because it sees no fluid and is freaking out
Probably also worth mentioning that I ordered the converter from Jake's and mentioned that it was for a 2000 4L80E bolting up to a 2002 4.8 with a stock flexplate, they said it would work just fine. I did have to elongate the flexplate mounting holes with a die grinder as the flexplate bolt pattern was the "small" one and didn't fit the "larger" (11.5"?) pattern of the converter
So I removed the converter bolts and made sure it was spinning freely - it was. Seating the converter all the way into the trans gives me just over .250" clearance between the converter pad and the dished flexplate, which from what I read is too much. I'm going to use some precision ground washers to space the converter back until there's 1/16"-1/8" gap.
Also, oddly enough, I had 10+ quarts in the trans and the dipstick was reading over full with engine running. Went to drain the trans to see if there was anything floating in the pan, and only 6 quarts came out....
Probably into the converter. Maybe it was just low on fluid, but I don't get why the dipstick kept reading very high, engine on or off, no changes. Maybe the aftermarket dipstick/tube is smearing as I remove it to check fluid, I don't know.
Also, I think I need to install a flexplate spacer between the flexplate and the converter. There is a gap between the converter snout and the crank hub with the converter fully seated against the flexplate.
1)Yes you need the spacer. It is possible that the pump gears are damaged already. Without the spacer the hub of the converter cant center in the back of the crankshaft. thus causing a bind in the gears on the crescent of the pump. when you start the motor it pops the inner gear.
2) The last two 4L80E's I Bench built, both customers complained of a no move. I told them they are going to need about 13-14 qts of fluid all together. less if its a small converter. They were only getting about 9 qts in them. the stick will read full or overfull until there has been enough time for the residual fluid from filling to run down the tube. it takes longer than most people think it should.
1)Yes you need the spacer. It is possible that the pump gears are damaged already. Without the spacer the hub of the converter cant center in the back of the crankshaft. thus causing a bind in the gears on the crescent of the pump. when you start the motor it pops the inner gear.
2) The last two 4L80E's I Bench built, both customers complained of a no move. I told them they are going to need about 13-14 qts of fluid all together. less if its a small converter. They were only getting about 9 qts in them. the stick will read full or overfull until there has been enough time for the residual fluid from filling to run down the tube. it takes longer than most people think it should.
I plan on sliding the transmission back from the block to verify the dimension between the bellhousing mounting pad and the converter mounting pad. That's step 1 in determining whether the converter is seated totally, regardless of flexplate/spacer type. I am learning that this is determined before the transmission ever comes near an engine.
Additionally I agree that I need the spacer, I have a new flexplate/spacer that just arrived and need to install it.
How does one inspect the pump for proper operation and/or damage? I assume the trans needs to come out, pump needs to be unbolted from the input shaft area, etc. Never messed with an 80E or even an automatic trans before so any input is much appreciated.
"How does one inspect the pump for proper operation and/or damage? I assume the trans needs to come out, pump needs to be unbolted from the input shaft area, etc. Never messed with an 80E or even an automatic trans before so any input is much appreciated."
Pull the converter out. Inspect the snout for damage at the tip that goes into the pump gears.
Look into the pump and see if the inner gear looks intact. If it is broken, the pump will need to be removed & checked for damage. Even if it doesn't look broken, I would pull the pump and inspect it. But for me I have all the required tools. If it comes to that we can cross that bridge it needed.
The plot thickens. No damage to pump, no scratches that can even catch a finger nail. The converter snout looked fine and I measured the gap between bellhousing flange and converter pads at just over 1".
Scratching my head here. Was it just low on fluid? If so, why did the fluid level not go down on the dipstick with the engine running?
The only other thing I can think of is that I was running a dished flywheel with no spacer, which Jake's Performance told me would work. I will be installing a flat flexplate with spacer.
Great pictures. it all looks good. make an alignment band and tighten pump bolts to 18 lbs ft. torque. I am a bit confused over the flex-plate set up my self on the 4L80E and the LS engines. I'm more of a 4L60E guy myself. I build 2 4L80E's (mostly stockers no swap's) a year and about 50 4L60E's. Looks like you have a very nice skill set, ability and desire to get to the root cause of the issue. I have attached a file sheet I give out to first time customers. It helps alleviate install errors. Not that you need it, but review some times helps me. it's also difficult to help without a hands on approach.
How many qts. of fluid did you get in?
Great pictures. it all looks good. make an alignment band and tighten pump bolts to 18 lbs ft. torque. I am a bit confused over the flex-plate set up my self on the 4L80E and the LS engines. I'm more of a 4L60E guy myself. I build 2 4L80E's (mostly stockers no swap's) a year and about 50 4L60E's. Looks like you have a very nice skill set, ability and desire to get to the root cause of the issue. I have attached a file sheet I give out to first time customers. It helps alleviate install errors. Not that you need it, but review some times helps me. it's also difficult to help without a hands on approach.
How many qts. of fluid did you get in?
Thanks very much for your posts, they've been very helpful. I am an engineer with experience in multiple disciplines (HVAC, medical device manufacturing, most recently working on F-35 fighter jet actuators), so asking the right questions is a key part of my job.
) with the spacer facing out towards the trans. Next step I suppose is reassembling the pump and reinstalling into trans, and throwing it back into the truck. I am wondering if there is a way to verify fluid flow by spinning the converter with the transmission out of the truck. Someone on one of these threads stated he could get fluid flow just by spinning the converter by hand, but I assume that's with the tranny already full to capacity.
I mentioned that I had fluid coming out of the cooler line when turning it over to install the converter bolts.
I wouldn't turn it over with the transmission sitting there with the converter in because there is no support. It won't end the world but it just doesn't seem good for it. I also wouldn't pull and install the pump with the trans sitting on the pan. Thats a gamble on the sealing rings. I'd turn it upright.
Also nice pics. You can see why to not use rags when rebuilding a transmission (or working on one).
The first th400 I built I used rags, it didn't run long before that lint worked it's way into the kickdown solenoid and made it stop shifting. It made cotton ***** in the pan, literally ***** of cotton. It took forever for that damn thing to shift right, even with dropping the pan and cleaning the solenoid every two days.
My suggestion is take the pan off and check the manual linkage. Then put it back in and add enough fluid.
good tip on the rags, it's a combination of sharp machined edges and the sticky oil that gets the fibers everywhere. I'll have to grab a couple cans of brake parts cleaner and a brass brush to clean it up.
Gonna try to slam this thing back in Sunday, wish me luck. Gotta buy more tranny fluid too!
Pump cleaned and reassembled, converter filled with 4 quarts and installed, depth checked at over an inch, fluid dribbling out cooler pressure port, flexplate with spacer installed.
Transmission in, filled up with 4 quarts. Started it up, Continued to add fluid. At no time did any fluid come out the cooler pressure port so I still have no pressure. To make sure I had enough fluid I kept adding oil until it started to dribble out the breather up at the bellhousing, meaning the case was full. I pulled the pan and checked the filter (which was new), nothing unusual, no clogs or debris. At this point I'm stumped.
Is there anything electrical that might cause the pump to bypass internally? Solenoids?
When you bolt the converter to the flex plate how far forward are you pulling the converter out of the pump? What is the space between the converter and flex plate with the converter pushed all of the way back into the pump?
The space between the converter pads and flexplate was just a hair under 1/8" with the converter pushed all the way into the trans. It rotated freely, you can hear the fluid sloshing inside. Pulled it forward by that amount to bolt up to the flexplate.
The space between the converter pads and flexplate was just a hair under 1/8" with the converter pushed all the way into the trans. It rotated freely, you can hear the fluid sloshing inside. Pulled it forward by that amount to bolt up to the flexplate.
2000 4L80E, no movement in any gears 
