4L60e vs 4l80E

I've done some basic research. I know the 80e is much stronger but I'm not sure if I need it. But I might.

The problem is I'm LQ9 swapping my 94 chevy 2500. It has a dying 5.0 and 4l60. I'm getting a deal on a LQ9 from a friend of mine. I was just about to settle for a 5.3 of some version and got offered a lq9 from an 02/03 escalade and ecu. So now I'm looking at a 4L65 or 4l80 to go with it.

I'll be keeping the engine completely stock other than headers/intake at the most. Im just replacing a dying engine so my truck can actually tow things, not making a hot rod truck. I will be towing my racecar and random cars on a 20ft trailer. It probably weighs 1500lbs or so, its built light. Cars will be typically 2500-3000lbs and maybe towing a truck or random heavy things rarely. So average loads will be 3000-4500lbs plus whatever tires/stuff in the truck bed. maybe 6000lbs on the high side.

So GRM what do you reccomend. 4l65e like what came stock behind the lq4 or 4l80e for complete durability.

you need a new trans anyway, right? so 4L80. if it wasn't a bear to swap my avalanche i'd have done that instead of rebuilding the 4l65

True. And I was just thinking....I could eventually upgrade to a two car hauler and maybe a 5th wheel. That would require a 4L80.

The matching transmission from the Escalade would probably help with simplifying the electronics. What would it have had in it?

I went from a 700R4(well, technically 3 of them ) in my C1500 to a 4L80 in my 1-ton van, and there's no comparing the two. The 4L80 is so much more robust. I follow the factor instructions to shift out of O/D for towing, but with this transmission it doesn't feel like you need to.

In reply to petegossett:

Interesting, the manual for my 2000 Silverado 2500 (has 4L80E) states that OD CAN be used for towing. My friend that owns a trans shop says the only trans that he would rather have than a 4L80E is an Allison 1000. They're a good unit for sure.

In reply to doc_speeder:

That's good to know. Mine is a '98 so I wonder if there were updates between those years, or if GM had just gained enough experience to know they'd last?

NV4500 FTW!

I swapped the trashed 4L80E in my K1500 and it's been the best upgrade ever. I can tow in overdrive, the granny gear and 4x4 mode will pull a house of its foundation.

4L80. No question.

Screw off truck? 4L60. Real truck, especially one that tows? 4L80, or go home.

If you're really towing some weight (more than 5000), 4L80E all the way. To build a 4L60E to handle that kind of abuse you could more than pay for the 4L80E.

GM ECMs are pretty easy to hack and can control many transmissions. Your programmer will likely start with a "van file" since the 6.0/4L80E was a pretty common combo in 3/4 ton vans.

Go 4L80E, you're already in there and won't cost much more. What kind of shape is the rest of the truck in?

t25torx wrote: NV4500 FTW! I swapped the trashed 4L80E in my K1500 and it's been the best upgrade ever. I can tow in overdrive, the granny gear and 4x4 mode will pull a house of its foundation.

i'm keeping an eye out for a 5 speed 4x4 rustbucket parts truck for when my 4L65 pukes again.

patgizz wrote:

t25torx wrote: NV4500 FTW! I swapped the trashed 4L80E in my K1500 and it's been the best upgrade ever. I can tow in overdrive, the granny gear and 4x4 mode will pull a house of its foundation.

i'm keeping an eye out for a 5 speed 4x4 rustbucket parts truck for when my 4L65 pukes again.

I found mine on car-part.com. I scoured CL for a long time and came up empty. I got the trans, shifter, pedals and other stuff for around a grand. I had to buy a bracket you have to weld to the firewall at the dealer, and the shift boot there also.

My friend actually has the engine in his 350z drift car and has dyno'd it at 345hp/354 lbs/ft with headers, intake and a tune. I think he means truck intake Im not sure:

Any way Id need headers/manifolds and a wiring harness. Engine is from a 03 escalade and ecu is from a 02 and VATS is removed already. So I need a transmission and harness.

I was also looking at the 6L80 but thats probably more money then I care to spend. I kinda want to dump the 6L in with the stock trans to blow it up. It already sucks, but I shouldn't waste time like that.

Towing in overdrive sounds awesome well at least some of the time. I'll put a better transcooler on it...

Towing in overdrive is fine, it's the shifting in and out that kills things. A clutch pack doesn't give a E36 M3 about the load across it right up until it actually starts slipping, and once that happens the problem isn't that you're towing, it's that the transmission is failing, because the overdrive components should NOT slip with the factory input torque no matter what is happening at the output.

So basically, dont shift in and out of overdrive under load over and over and over.

In reply to Vigo:

So only shift from drive to overdrive once you're on the highway & up to speed?

My opinion is just don't shift under power. Let off for upshifts, let off a little less for (manually forced) downshifts (engine power helps keep the trans from having to accelerate the engine with a slipping clutch pack).

Once a clutch pack is locked up, it takes no additional wear and creates no additional heat from varying loads (unless it actually slips). Any additional heat in the trans at that point would be coming from a torque converter staying unlocked because of throttle angle, which isn't always an issue.

If you go out of your way to protect your overdrive gear by shifting consciously under light/no power and never let it 'hunt', it will be completely fine.

patgizz wrote:

t25torx wrote: NV4500 FTW! I swapped the trashed 4L80E in my K1500 and it's been the best upgrade ever. I can tow in overdrive, the granny gear and 4x4 mode will pull a house of its foundation.

i'm keeping an eye out for a 5 speed 4x4 rustbucket parts truck for when my 4L65 pukes again.

Pat, I found this today and thought about you.

BoostedBrandon wrote:

patgizz wrote:

t25torx wrote: NV4500 FTW! I swapped the trashed 4L80E in my K1500 and it's been the best upgrade ever. I can tow in overdrive, the granny gear and 4x4 mode will pull a house of its foundation.

i'm keeping an eye out for a 5 speed 4x4 rustbucket parts truck for when my 4L65 pukes again.

Pat, I found this today and thought about you.

mine is 05 so i need a 99+

already have a 90 5 speed truck.

I thought the main advantage of the 4L80 over the 4L60, besides being beefy, was that you COULD tow in overdrive, since the 700R4/4L60 doesn't send fluid through the cooler in OD while the 4L80 does.

Which is also, incidentally, why all 700-R4s (except Corvette) would not allow shifting past 3rd gear at WOT...

Knurled, the 4L60 does send fluid through the cooler in OD, but between the lower engine rpms and the TCC being engaged, the fluid flow is reduced quite a bit. Which of course can lead to higher temps, still a good idea not to tow in OD.

I had a stock, low mileage 86 IROC that shifted into OD at WOT. Good thing it did as it barely cleared the century mark in drive. Not that I would condone doing anything like that.

I would choose a 4L80 for towing, just for the reliability factor. There is the 4L85 if you want a little more strength, they are usually found behind 8.1L BBCs.

In reply to Knurled:

My truck came with a 4L80E behind the 6.5L TD. There's a sticker on the door that specifically says not to tow in OD with it.

Uh now I just want to get started on this swap. This 305 needed to be gone 20k miles ago.

Rustspecs13 wrote: Towing in overdrive sounds awesome well at least some of the time. I'll put a better transcooler on it...

In reality my 6.0 tows fine in OD as long as the aero of the trailer is decent, like an open car hauler. With my 5th wheel RV I just tow in D unless there is a tail wind. The gassers just don't have the low-down grunt to tow much in OD without constant shifting up and down. My 6.0 3.73 geared truck runs 1950 rpm at 60mph in OD and 2500 rpm in D. The combination of being up higher in the torque band and just the 25% greater mechanical advantage of the lower gear makes a huge difference. So don't get too hung up on pulling in OD as realistically it may not happen that often.