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4l80e and the differences between years

Yeah, $1600 for the stock rebuild that will last you another 200K miles, or $600 (or free) for an unknown used transmission that may last you for 200 blocks.
 
Ok, here goes...
I own a 1993 K2500 with the 6.5 TD. I want to swap that engine with a 2004 built 6.0. I am adding power. I want to keep my tranny, case, etc just not sure what upgrades I can do to that tranny to make it hold. I am not going for race, but I will be using the truck to pull my 5000 lb. RV. Also need recommendations for a 2000 rom stall.
Thanks for the help
 
Should make a nice high revving truck engine.

First thing is make sure your dmv allows it. Some places don’t- ive seen some rigs get decent time and money put in only to sell for cheap because they won’t let it be registered.

Include new sae30r9 fuel hose everywhere when you swap. Drop and inspect that fuel tank also- the inside coating peels off and creates issues of plugging the diesel filter of 5 microns- but you will probably remove and sell yours- gas needs a 10 micron and paper style is not recommended. Holley makes some nice cleanable ones.
Do sell or donate the old diesel, even if not running. Someone out there might need some parts of it and they aren’t always easy to find as you might have experienced.

I will leave the trans recommendations to those way better knowledge than I have.

Please do a thread here later when finished or as you go on the conversion. We enjoy it and others might learn something from it. Your engine choice is exactly my favorite gas option btw.
 
Will L. said:
Should make a nice high revving truck engine.

First thing is make sure your dmv allows it. Some places don’t- ive seen some rigs get decent time and money put in only to sell for cheap because they won’t let it be registered.

Include new sae30r9 fuel hose everywhere when you swap. Drop and inspect that fuel tank also- the inside coating peels off and creates issues of plugging the diesel filter of 5 microns- but you will probably remove and sell yours- gas needs a 10 micron and paper style is not recommended. Holley makes some nice cleanable ones.
Do sell or donate the old diesel, even if not running. Someone out there might need some parts of it and they aren’t always easy to find as you might have experienced.

I will leave the trans recommendations to those way better knowledge than I have.

Please do a thread here later when finished or as you go on the conversion. We enjoy it and others might learn something from it. Your engine choice is exactly my favorite gas option btw.
Click to expand...
Thanks for the reply. I will certainly check with the DMV. Here, in Florida, it shouldn't be an issue, hopefully.
The fuel tank will be replaced. The engine will be sold along with all the upgrade parts I bought for it. It only has 180K and well cared for so I'm thinking it will sell pretty fast.
 
Lonncarr said:
Thanks for the reply. I will certainly check with the DMV. Here, in Florida, it shouldn't be an issue, hopefully.
The fuel tank will be replaced. The engine will be sold along with all the upgrade parts I bought for it. It only has 180K and well cared for so I'm thinking it will sell pretty fast.
Click to expand...
After an XX amount of posts You can advertise the components in the classifieds portion of the forum here.
Might just be some members interested in some, or all if You dont want to break it down.
 
@Lonncarr the nice thing about the 4L80E is that it is essentially a TH400 with an Overdrive section and locking torque converter added to it. The bad news, is its weakest links are the Overdrive section and lock up torque converter. All the tricks to beef up a TH400 - Koleen steels, Red Alto clutches, increasing the number of steels/clutch discs, using the heavy duty 34 sprag, forged steel drums, etc, will definitely help 1-3 gears, using a Kevlar Reverse band, upgrading the OD actuating piston in the valve body, upgrading the Torque Converter to a billet high friction single clutch or full-out triple clutch.

The 4L80E is NOT designed for engine braking and there's really no way to beef it up/modify it to be used that way.
 
Yes sir. I have every upgrade available for it and totally understand they come with no guarantees...I appreciate your words.
 
Lonncarr said:
Ok, here goes...
I own a 1993 K2500 with the 6.5 TD. I want to swap that engine with a 2004 built 6.0. I am adding power. I want to keep my tranny, case, etc just not sure what upgrades I can do to that tranny to make it hold. I am not going for race, but I will be using the truck to pull my 5000 lb. RV. Also need recommendations for a 2000 rom stall.
Thanks for the help
Click to expand...
If it was mine, I would not run a 91-93 trans. I know others do it, but there is quite a few mods that should be done to make a 91-93 trans work properly being controlled by an LS PCM or an aftermarket tcm. The 91-93 trans uses a different epc solenoid as well as a slightly different pressure control circuit. It needs to be upgraded to a 94+ style epc circuit to be controlled by an LS controller or aftermarket controllers.
 
THEFERMANATOR said:
If it was mine, I would not run a 91-93 trans. I know others do it, but there is quite a few mods that should be done to make a 91-93 trans work properly being controlled by an LS PCM or an aftermarket tcm. The 91-93 trans uses a different epc solenoid as well as a slightly different pressure control circuit. It needs to be upgraded to a 94+ style epc circuit to be controlled by an LS controller or aftermarket controllers.
Click to expand...
You are exactly correct. My son is the LS guy and I'm more old school. He told me to use the 4L80E that came out of the donor truck with the engine and that is what we are going to do. I will, very soon, be selling the 6.5, transmission and parts that I was going to bulletproof it with as a package deal. The truck only has 180,000 original miles.
I am also considering taking the front diff as well. The donor truck o ly had 83,000 miles on it. I will be going threw the transmission as well as buying an aftermarket converter.. like they say, go big or go home...
 
Husker6.5 said:
@Lonncarr the nice thing about the 4L80E is that it is essentially a TH400 with an Overdrive section and locking torque converter added to it. The bad news, is its weakest links are the Overdrive section and lock up torque converter. All the tricks to beef up a TH400 - Koleen steels, Red Alto clutches, increasing the number of steels/clutch discs, using the heavy duty 34 sprag, forged steel drums, etc, will definitely help 1-3 gears, using a Kevlar Reverse band, upgrading the OD actuating piston in the valve body, upgrading the Torque Converter to a billet high friction single clutch or full-out triple clutch.

The 4L80E is NOT designed for engine braking and there's really no way to beef it up/modify it to be used that way.
Click to expand...
Not entirely true. I found this available from sonnax. It applies the overrun clutch at all times except OD in order to strengthen the overdrive roller clutch. Also makes it so gears 1-3 have engine braking while in D. I put it in the transmission of my Suburban.
www.sonnax.com

Smart-Tech® Overrun Clutch Valve Kit - 34200-40K

Extend the life of workhorse 4L80-E transmissions while preventing warranty claims and comebacks. Patented, easy-to-install kit #34200-40K.
www.sonnax.com www.sonnax.com
 
Tombrewster421 said:
Not entirely true. I found this available from sonnax. It applies the overrun clutch at all times except OD in order to strengthen the overdrive roller clutch. Also makes it so gears 1-3 have engine braking while in D. I put it in the transmission of my Suburban.
www.sonnax.com

Smart-Tech® Overrun Clutch Valve Kit - 34200-40K

Extend the life of workhorse 4L80-E transmissions while preventing warranty claims and comebacks. Patented, easy-to-install kit #34200-40K.
www.sonnax.com www.sonnax.com
Click to expand...
While it allows engine braking in 3-2-1, which the core TH400 clutches/steels are capable of handling, that kit still does not address the 4L80E's basic shortcommings, that being you can not engine brake in OD, with or without a heavy load/towing, without eventually tearing/burning out the OD section as the design just does not allow for enough steels and frictions to handle the load, nor does the OEM-design torque converter, either, with its wimpy lock-up clutch and easily warped housing that can only be adequately addressed by going with a billet converter and a double or triple disc, high friction clutches.

If you notice in Sonnax's own literature, it states that this kit prevents warranty claims and comebacks - that is it will (hopefully) let the tranny last beyond the warranty period offered by that shop, be it a 1/12K, 2/24K or 3/36K warranty or whatever.

There really is no permanent "fix" for the weak TCC or wimpy OD clutch design that prevents being able to engine brake (using some sort of exhaust braking device) with a 6.5TD/4L80E combo in OD, as you can with an Allison or the Aisin or newer Ford transmissions behind those diesels, only the way Sonnax devised to delay the inevitable mechanical failure of the TCC and/or OD clutch section to save shops having to eat the labor/parts to repair and replace either during their warranty period. Believe me, if there was an actual, permanent "fix" to the crappy TCC/OD issue that would allow engine braking in OD with the TCC locked - it would have already been invented and somebody very, very wealthy from it 20 years ago.

The problem with the 4L80E from the start is that it was a stop-gap, light-duty transmission - behind a light-duty diesel engine - that was modified with an add-on OD section and a locking TC for one purpose only - to get the maximum fuel mileage possible out of GM's pickup truck line, not to be used in the unforseen ways that the engineers never envisioned and that have been attempted since its introduction. Those people who intended the 6.5 for Medium Duty-type use went with a manual transmission behind it for good reason - the same reason why the military had the TH400, not the 4L80, in the HMMMV - because of its issues.
 
Husker6.5 said:
While it allows engine braking in 3-2-1, which the core TH400 clutches/steels are capable of handling, that kit still does not address the 4L80E's basic shortcommings, that being you can not engine brake in OD, with or without a heavy load/towing, without eventually tearing/burning out the OD section as the design just does not allow for enough steels and frictions to handle the load, nor does the OEM-design torque converter, either, with its wimpy lock-up clutch and easily warped housing that can only be adequately addressed by going with a billet converter and a double or triple disc, high friction clutches.

If you notice in Sonnax's own literature, it states that this kit prevents warranty claims and comebacks - that is it will (hopefully) let the tranny last beyond the warranty period offered by that shop, be it a 1/12K, 2/24K or 3/36K warranty or whatever.

There really is no permanent "fix" for the weak TCC or wimpy OD clutch design that prevents being able to engine brake (using some sort of exhaust braking device) with a 6.5TD/4L80E combo in OD, as you can with an Allison or the Aisin or newer Ford transmissions behind those diesels, only the way Sonnax devised to delay the inevitable mechanical failure of the TCC and/or OD clutch section to save shops having to eat the labor/parts to repair and replace either during their warranty period. Believe me, if there was an actual, permanent "fix" to the crappy TCC/OD issue that would allow engine braking in OD with the TCC locked - it would have already been invented and somebody very, very wealthy from it 20 years ago.

The problem with the 4L80E from the start is that it was a stop-gap, light-duty transmission - behind a light-duty diesel engine - that was modified with an add-on OD section and a locking TC for one purpose only - to get the maximum fuel mileage possible out of GM's pickup truck line, not to be used in the unforseen ways that the engineers never envisioned and that have been attempted since its introduction. Those people who intended the 6.5 for Medium Duty-type use went with a manual transmission behind it for good reason - the same reason why the military had the TH400, not the 4L80, in the HMMMV - because of its issues.
Click to expand...
Ahh, I see, you were talking about exhaust/engine braking. I was simply saying there was something available to prolong the life of the OD components while providing normal off throttle engine braking. I wasn’t even thinking of exhaust brake because they are extremely uncommon on 6.5TDs.

not sure why you say military didn’t use the 4l80 though.
 
There is no "off throttle engine braking" in a diesel, as it lacks a throttle butterfly and thus there is a continuous, unobstructed flow of air into the engine and not engine braking effect like you would het letting off the throttle in a gas engine. The only way to get off throttle engine braking with a diesel is with an exhaust brake device that causes exhaust back pressure into the cylinder when the exhaust valve is open.

As for that update you posted the link to, that was published 10 years after I got out, but when I was in all of our 6.2/6.5 powered HMMMVs were 100% mechanical for both injection and automatic transmission, a TH400. I am totally astounded that DARPA would allow the failure-prone by design 4L80E in grossly overweight upfitted HMMMV variants, especially when the lives of the crew depends on the transmission not failing under high stress loads such as full throttle acceleration upgrade with an additional 6-7000 pounds of field expedient up armoring/blast hardening.

And that Sonnax kit doesn't extend the life of anything in the OD section that was under engineered physically to start with. The only thing it does is increase the apply pressure to the already undersized OD clutch to get it to hold from slipping during the rebuilder's warranty period - thus Sonnax's own statement that it doesn't "fix" or "cure" anything, it just prevents "warranty claims" and "comebacks" - that is a rebuild shop spends the bucks on the kit as insurance against eating $1+K in labor/parts when the OD section fails before the rebuilder's warranty expires or comebacks because the customer complains that the tranny is dropping out of, or slipping, in OD.

The OD section will fail on these sooner or later - sooner with heavy towing/abuse and later if it's babied - as it's a physical design flaw of a serious lack of friction and steel contact surface area that just can not be prevented by just increasing pressures and then expect some miraculous increase in the transmission's life. Especially without addressing the other weak link that is usually the trigger to the 4L80E failure avalanche - the TCC. Which fails and then takes out the OD section which then takes out the rest of the transmission. No, that Sonnax kit does not make the OD section live longer, it is just insurance to make sure the OD section outlives the rebuilder's warranty.
 
Just fyi- the 4l80e has a shorter life in hmmwv and civy Hummers than in an equally weighted pickup.

I think this is because there is poor slow speed airflow over the transmission cooler. It is a stand alone of descent size, no in radiator cooling loop. So average operation temp is higher that in pickups. When the fan is engaged the temperature recovers better due to the larger cooler. In the fleets behind 6.5 we saw over 300,000 miles from most transmission in moderate weight use.

Talking to family in USMC (wrench turners) the hmmwvs that are under 10,000 lbs last into refurbishment which is always under 100,000 miles. The up armoured units tend to eat a trans more often but didn’t have any numbers they could throw estimates at.
Common practice it basic filter & fluid, then r&r on those units if the new fluid didn’t ease it up because repair rate is low and the down time is bad. So they will r&r it and rebuild the trans as another standby for the lighter rigs. They don’t bother with rebuilds in the heavy units.
 
Husker6.5 said:
There is no "off throttle engine braking" in a diesel, as it lacks a throttle butterfly and thus there is a continuous, unobstructed flow of air into the engine and not engine braking effect like you would het letting off the throttle in a gas engine. The only way to get off throttle engine braking with a diesel is with an exhaust brake device that causes exhaust back pressure into the cylinder when the exhaust valve is open.

As for that update you posted the link to, that was published 10 years after I got out, but when I was in all of our 6.2/6.5 powered HMMMVs were 100% mechanical for both injection and automatic transmission, a TH400. I am totally astounded that DARPA would allow the failure-prone by design 4L80E in grossly overweight upfitted HMMMV variants, especially when the lives of the crew depends on the transmission not failing under high stress loads such as full throttle acceleration upgrade with an additional 6-7000 pounds of field expedient up armoring/blast hardening.

And that Sonnax kit doesn't extend the life of anything in the OD section that was under engineered physically to start with. The only thing it does is increase the apply pressure to the already undersized OD clutch to get it to hold from slipping during the rebuilder's warranty period - thus Sonnax's own statement that it doesn't "fix" or "cure" anything, it just prevents "warranty claims" and "comebacks" - that is a rebuild shop spends the bucks on the kit as insurance against eating $1+K in labor/parts when the OD section fails before the rebuilder's warranty expires or comebacks because the customer complains that the tranny is dropping out of, or slipping, in OD.

The OD section will fail on these sooner or later - sooner with heavy towing/abuse and later if it's babied - as it's a physical design flaw of a serious lack of friction and steel contact surface area that just can not be prevented by just increasing pressures and then expect some miraculous increase in the transmission's life. Especially without addressing the other weak link that is usually the trigger to the 4L80E failure avalanche - the TCC. Which fails and then takes out the OD section which then takes out the rest of the transmission. No, that Sonnax kit does not make the OD section live longer, it is just insurance to make sure the OD section outlives the rebuilder's warranty.
Click to expand...
I think you’re slightly misunderstanding what it does. During normal drive operation, in gears 1-3 the OD section is only relying on the roller clutch. That is what’s prone to failure, and what causes the catastrophic failures. When you shift to 3,2,or 1 manually it uses the overrun clutch as well. This kit makes it so in normal drive operation the overrun clutch complements the roller clutch to reduce the stress on it, thereby preventing the roller clutch from being over stressed.

I’m sure you’re right about the needing an exhaust brake for any meaningful sort of engine braking though. And I wasn’t aware that the military ended up dropping this trans in favor of all mechanical (smart move).
 
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