4L80E Information Thread

[dragstews]

You could keep the NP 203 in play with using a 4L80 ..

Forgot to say, the transfer case shifter will need a fabricated mount made-up due to the stock mounting points are no longer there .. The custom adapter plate uses them ..

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I moved the shifter far forward and centered it to make it appear like it was a transmission floor shifter ..

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Trans shifter is a column shift ..

 

[AuroraGirl]

@NickTransmissions hey. My 4l80e is getting the “transmission component slipping” code and then defaulting to high line pressure(pcs doesn’t appear to be dynamic or change when the code sets and the shifting becomes harsh)

The TCC lockup also appears to no longer occur when the code is set?

Anyway, the only thing I can tell is during live data the “slips” appear to be under coast or moderate throttle in 3-4 gear speeds

Resetting the codes gets the shifts back to normal pressure.

The TCC Lockup at 98% seems to have a slip speed of 50-150rpm under normal conditions but any uphill or coasting it dives into negatives (-400 rpm at worst, but usually -50 to -100) sometimes and then upwards 400rpm, but goes back to 150 or less quickly.

The “slipping” is never actually felt/perceived, I have to keep the live data up in order to know “when it happens”

Any thoughts on diagnosis? The 4l80e is original 2005 model year, towed heavy in its first few years, fluid kept on schedule

I checked the fluid level twice recently and it’s full I think. It’s been -30 so I can’t actually get more than like 100 degrees on the trans even with driving but I’ll check again when it’s like 30 degrees out. Dipstick showed dark red, mileage wise the fluid will be due in like 10k, and where it should be on the dipstick.

Reverse works normally, if that matters. My shifter cable is getting sloppy, should be replaced soon. The lever on the trans makes a loud clunk when shifting out of park sometimes

 

[HotRodPC]

@NickTransmissions hey. My 4l80e is getting the “transmission component slipping” code and then defaulting to high line pressure(pcs doesn’t appear to be dynamic or change when the code sets and the shifting becomes harsh)

The TCC lockup also appears to no longer occur when the code is set?

Anyway, the only thing I can tell is during live data the “slips” appear to be under coast or moderate throttle in 3-4 gear speeds

Resetting the codes gets the shifts back to normal pressure.

The TCC Lockup at 98% seems to have a slip speed of 50-150rpm under normal conditions but any uphill or coasting it dives into negatives (-400 rpm at worst, but usually -50 to -100) sometimes and then upwards 400rpm, but goes back to 150 or less quickly.

The “slipping” is never actually felt/perceived, I have to keep the live data up in order to know “when it happens”

Any thoughts on diagnosis? The 4l80e is original 2005 model year, towed heavy in its first few years, fluid kept on schedule

I checked the fluid level twice recently and it’s full I think. It’s been -30 so I can’t actually get more than like 100 degrees on the trans even with driving but I’ll check again when it’s like 30 degrees out. Dipstick showed dark red, mileage wise the fluid will be due in like 10k, and where it should be on the dipstick.

Reverse works normally, if that matters. My shifter cable is getting sloppy, should be replaced soon. The lever on the trans makes a loud clunk when shifting out of park sometimes

hmmm, you mention sloppy cable, and clunk coming out of park sometimes. That would make me, for the purpose of checking easy things first, wonder if you manual valve and linkage isn't out of adjustment. IF the manual valve isn't lined up properly with passages, it can certainly affect fluid pressures. LIke if the window on the manual valve is only half way open instead of fully open, and if that's possibly letting a bleed happed into another passage that shouldn't be getting any pressure at all, those things can for sure cause some issues. I'm not familiar with 4L80-E, but the manual valve adjustment or position, is Auto Trans 101 and would apply to any and all auto transmissions.

 

[RanchWelder]

Yup. Half way into or out of gear is bad for the system.
If your reverse piston is cracked, due to reverse to drive fast shifting, such as plowing, your reverse piston cup might be cracked and leaking or failing to move accordingly due to a shift in geometry of the reverse 3rd piston actions. This is a common issue, if the reverse piston is cracked. I would tear it down immediately and verify the components are within spec before you ruin the case.

Maybe Nick has a better solution from his advanced technical experience.

In my mind, after what I went through remanufacturing my own unit, it would be ripped out before it ruins the hard parts and causes catastrophic failure.

There's no fix for slipping or converter failure. You have to rip it out and fix it once this starts.
There's a possibility the valve body has contamination and the seals might be torn.
There's no way to know without an autopsy.

The bench test for the valve body is essential for proven system efficiency.

If there's contamination or a ruined solenoid, you might get buy with a test and replacement solenoid.
However once the meal affects the friction plates. there's no easy solution. Metal ruins the 3rd gear contact.
If the reverse servo piston is cracked, you may not have a reverse issue, just a leak in 3rd and slip.

The reprogram solution can remediate the issues going forward. I would strongly advise you to reprogram with Nick, so your rebuild is correct and from a single reprogram engineering source.

Or I'll build you one if you want and Nick is too busy.

The core costs are out of this world.

The aluminum industry got caught sneaking ingots from Russia to Canada via Israel.

Everything is about to double in commodities market.

Save your case before you need a new one.

The price of silver just dropped after a screaming climb, however aluminum may never drop.
Not in your lifetime.

The first US smelter for aluminum since 1994 just got proposed this week.
It will also process Rare Earth's and Gold/Silver in MT.
It's also associated with Military production. So we will get nothing at the consumer level from this, YET.
It will take 2 years to complete if it actually happens.
We should build five more within the same timeframe for NATSEC.

I'm tooled up with a home shop for at least another year or two.
My cadaver bench is ready for another 4L80-E.

If you want me to rebuild it, I can do it for you on the cheap.
I'll document it and buy the same parts from the same suppliers I used to rebuild my HD unit, good for 750HP.

I relocated to another home in MT with a shop and heated garage.

Let me know if I can assist.

In any event, good luck with your issue AG.

 

[NickTransmissions]

@NickTransmissions hey. My 4l80e is getting the “transmission component slipping” code and then defaulting to high line pressure(pcs doesn’t appear to be dynamic or change when the code sets and the shifting becomes harsh)

The TCC lockup also appears to no longer occur when the code is set?

Anyway, the only thing I can tell is during live data the “slips” appear to be under coast or moderate throttle in 3-4 gear speeds

Resetting the codes gets the shifts back to normal pressure.

The TCC Lockup at 98% seems to have a slip speed of 50-150rpm under normal conditions but any uphill or coasting it dives into negatives (-400 rpm at worst, but usually -50 to -100) sometimes and then upwards 400rpm, but goes back to 150 or less quickly.

The “slipping” is never actually felt/perceived, I have to keep the live data up in order to know “when it happens”

Any thoughts on diagnosis? The 4l80e is original 2005 model year, towed heavy in its first few years, fluid kept on schedule

I checked the fluid level twice recently and it’s full I think. It’s been -30 so I can’t actually get more than like 100 degrees on the trans even with driving but I’ll check again when it’s like 30 degrees out. Dipstick showed dark red, mileage wise the fluid will be due in like 10k, and where it should be on the dipstick.

Reverse works normally, if that matters. My shifter cable is getting sloppy, should be replaced soon. The lever on the trans makes a loud clunk when shifting out of park sometimes

Component Slipping codes are almost always torque converter-related in 4L80Es which, given your lack of noticable drivability symptoms points to valves in the valve body and/or pump:
1. TCC regulator valve (valve body) - output spool-bore is often worn and if yours is pulling single digit Hg readings under vacuum testing, it needs to be replaced with a Sonnax TCC reg valve
2. TCC control valve (pump) - bore plug/balance spool is worn, likely only holding low double digits or single digits.

Since you haven't mentioned any drivability issues, I'd start with vacuum testing the valve body or simply replacing the TCC regulator valve and PWM solenoid with a Sonnax TCC regulator valve and Rostra 4L80E PWM solenoid.

Note - Any time a transmission-related DTC sets/stores, you will have a default high line pressure strategy applied by the ECM to protect the trans from slipping. As a result, all upshifts, esp 1-2, will be firmer. Reverse and the shift cable are non-factors.

hmmm, you mention sloppy cable, and clunk coming out of park sometimes. That would make me, for the purpose of checking easy things first, wonder if you manual valve and linkage isn't out of adjustment. IF the manual valve isn't lined up properly with passages, it can certainly affect fluid pressures. LIke if the window on the manual valve is only half way open instead of fully open, and if that's possibly letting a bleed happed into another passage that shouldn't be getting any pressure at all, those things can for sure cause some issues. I'm not familiar with 4L80-E, but the manual valve adjustment or position, is Auto Trans 101 and would apply to any and all auto transmissions.

There's no adjustment on the 4L80E manual valve so if the shifter is able to move the rooster comb in the transmission along the detents at all, it will place the manual valve in the proper range position each time. A loose/worn cable will eventually present as no range position shifting symptom and the cable may actually snap/separate at the junctions between it's mount location on the steering column and the mount on the side of the transmission/selector shaft linkage bracket arm

 

[AuroraGirl]

Component Slipping codes are almost always torque converter-related in 4L80Es which, given your lack of noticable drivability symptoms points to valves in the valve body and/or pump:
1. TCC regulator valve (valve body) - output spool-bore is often worn and if yours is pulling single digit Hg readings under vacuum testing, it needs to be replaced with a Sonnax TCC reg valve
2. TCC control valve (pump) - bore plug/balance spool is worn, likely only holding low double digits or single digits.

Since you haven't mentioned any drivability issues, I'd start with vacuum testing the valve body or simply replacing the TCC regulator valve and PWM solenoid with a Sonnax TCC regulator valve and Rostra 4L80E PWM solenoid.

Note - Any time a transmission-related DTC sets/stores, you will have a default high line pressure strategy applied by the ECM to protect the trans from slipping. As a result, all upshifts, esp 1-2, will be firmer. Reverse and the shift cable are non-factors.


There's no adjustment on the 4L80E manual valve so if the shifter is able to move the rooster comb in the transmission along the detents at all, it will place the manual valve in the proper range position each time. A loose/worn cable will eventually present as no range position shifting symptom and the cable may actually snap/separate at the junctions between it's mount location on the steering column and the mount on the side of the transmission/selector shaft linkage bracket arm

How hard is it to vacuum test the valve body? as soon as its not winter, and i fix my starter in my f150, and have some paychecks stacked up ill plan to pull the pan and valve body and go over the components and maybe do some sonnax fixes you recommend and testing

 

[NickTransmissions]

How hard is it to vacuum test the valve body? as soon as its not winter, and i fix my starter in my f150, and have some paychecks stacked up ill plan to pull the pan and valve body and go over the components and maybe do some sonnax fixes you recommend and testing

Easy if you have the equipment to do it:
4L80E Valve Body Vacuum Testing - Smoked Jasper Unit Follow Up

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[AuroraGirl]

Easy if you have the equipment to do it:
4L80E Valve Body Vacuum Testing - Smoked Jasper Unit Follow Up

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I have plexiglas stock (thank you early covid working at a factory, when they switched from using dividers to using individual desks for the cafeteria, I got SHEETS of thick plexiglass for free, hundreds of dollars worth they were just throwing away. So wasteful.

Anyway, I have an HVAC vacuum pump would that work for this?
If it would, then i just need the block and plugs and those pad things

 

[HotRodPC]

How hard is it to vacuum test the valve body? as soon as its not winter, and i fix my starter in my f150, and have some paychecks stacked up ill plan to pull the pan and valve body and go over the components and maybe do some sonnax fixes you recommend and testing

I was going to say but he did now, IF YOU HAVE THE EQUIPMENT.... I'd probably just take his word for it, and replace the parts he's suggesting. Also, another thing I've learned, if Sonnax makes an aftermarket part for a correction or make it better, it's likely due to a common problem so if they've engineered a fix for it, then I do the Sonnax fix. So there's 2 things, Nick and Sonnax, that tells me, you're not wasting your money to do it. If it doesn't correct your problem, it's not money wasted and would have needed it eventually anyway.

 

[RanchWelder]

The A/C pump will work. You'll still need a test manifold.

You can't beat this price for the standard test unit:



His price is $25 less than Jeg's sale price?
They have it for $280.00. Sum is $283.99.

$370 to $407 everywhere else.

The Manufacturer Sonnax Industries has them on Back-order until next month.
If you reach out to Summit or Jeg's, they will Price-Natch this eBay seller and beat it by $1.00/
Your card will be charged only when it drop-ships from Sonnax.

Either way, the price is only low like this once a year.

My bench test unit was stolen Nov 2024. One rebuild on it.

My order tonight, (thanks to you AuroraGirl), was $254.22.
Supposed to ship by February 22, however it may not charge the card or ship until March when Sonnax has them back in stock


Gotta love Price Match!


My Jasper unit was smoked.

Thanks for your excellent tech video's Nick.

 

[NickTransmissions]

I have plexiglas stock (thank you early covid working at a factory, when they switched from using dividers to using individual desks for the cafeteria, I got SHEETS of thick plexiglass for free, hundreds of dollars worth they were just throwing away. So wasteful.

Anyway, I have an HVAC vacuum pump would that work for this?
If it would, then i just need the block and plugs and those pad things

Regular HVAC pump should work fine for the vac testing. You can make any number of test plates as long as you have the plexiglass and Sonnax vac test instructions.

There's one location, the forward abuse valve balance spool, for testing 4L60E valve bodies that Sonnax doesn't specify so if you're planning on making a test plate for those units, let me know and I'll show you where to make the test hole location.

 

[RanchWelder]

Cool.
Make 2?
Make one for me, AuroraGirl... ?

The small plate comes with the kit. So I have that one.
The bigger ones are way too expensive for my budget.
They make VB testing much easier.
I'm out of plexi.

The eBay seller offering the great price had the account blocked for some strange reason, after Summit Racing approved the price match?

Best bet is the deal from Jegs or price match with either one after locating the deal that they will match?

So much nonsense and pitfalls when buying these days.

Love the large vacuum plate for the 4L80-E, 4L85-E if you will scarf and drill me one?

There's so many specialty parts to own before you can remanufacture a quality transmission.

Would be grateful to learn and rebuild a select few, so as to keep it simple. (As much as any transmission rebuild could be simple... LOL.)

Love taking apart complex systems and re-designing them for efficiency.