The mythical CUCV 4L80E swap

[True Knight]

This is a great thread--- thanks to ALL you guys!!! Was considering 4L80E swap sometime ago but instead went with the Gear Vendors install to my 1008, finally, and it's a wee-bit disappointing that with the TH400/GVunit, you really only gain about 8-10 mph speed increase in overdrive. So now instead of screaming along with high RPM's to do 50-55 mph, I now can cruise an easy at 60-65 turning 2350-2500rpm, not bad for the slow truck lanes, but still not fast enough and more RPM's than I want to maintain engine's longevity.

Am currently driving the truck daily, 100 mile round trips.

This result makes now me ready for next logical step--- 4L80E swap, which will boost my final output to something like 2:62 to 1, as per GV's trans/gearing chart. So my next step is finding the trans locally, then a reputable builder, and with this and a few other good write-ups, plus the obligatory 2-3K OR MORE in $$$, BINGO--- I'll finally have a low-geared off-road capable, highway cruising, fuel pinching truck to expedition with... BTW; the GV unit helped truck gain in fuel milage with a combined city/highway of 17MPG, using GPS for accuracy. Looking forward to better!

P.S. Anyone's thoughts on an NA 6.2L/NV5400 swap instead?

Ciao~!

Thanks. As an update I drive the thing all the time and still going strong. The truck has just over 60k miles now, so about 20k on this trans. My round trips to work are about 60 miles. I usually run it at 70-75 mph (traffic permitting) and at that speed the rpm is around 2000-2300. I'm sure if I could cruise at 65 my mpg would be much higher as well. Ha ha.

 

[Dave Kay]

Thanks. As an update I drive the thing all the time and still going strong. The truck has just over 60k miles now, so about 20k on this trans. My round trips to work are about 60 miles. I usually run it at 70-75 mph (traffic permitting) and at that speed the rpm is around 2000-2300. I'm sure if I could cruise at 65 my mpg would be much higher as well. Ha ha.

Thanks again Knight, that's about what I'm aiming for; 2000-2300 rpm max, and the reason is mainly fuel mileage. But I like that I will still have the ability to gear-split it down for long grades, keeping the R's nice-n-easy, and ALSO keeping the big rigs off my tail! Uh-Huh!

Read a publication from The Diesel Page where they claim that dyno-testing numbers show an average loaded, N/A 6.2 gets best efficiency/mpg at around 1800-2300, with the lower R's getting better mileage than higher, like maybe a 4-5 mpg difference. These stats also claim that at these rpm's you still maintain peak torque so you won't lug your engine while trying to pass busloads of blue-haired grandmas' on the I-40 on their way to Laughlin... YUP!

Next step after 4L80e? Very likely--- banks Turbo!

Regards

 

[wayne pick]

Dave, adding a turbo will really make your truck come alive with the OD trans. I have a 700-R4 with the Banks turbo, and it pulls real nice in 3rd and 4th gear. BTW, Are you IUOE? I figured as much by your avatar.

 

[Dave Kay]

Dave, adding a turbo will really make your truck come alive with the OD trans. I have a 700-R4 with the Banks turbo, and it pulls real nice in 3rd and 4th gear. BTW, Are you IUOE? I figured as much by your avatar.

Hey Wayne--- yup--- IUOE Local 12 Los Angeles--- 25 years and counting... and even when work was fairly bad here, past 5 years, was still keeping head above water and minimal truck projects going. Meanwhile... are you also Operating Engineers too? Let's hear about it bro!

Regards

 

[wayne pick]

Hea Dave, Im a lowly dirt pusher with Local 137 in Briarcliff Manor NY. I run Excavators, Dozers, ETC. No Tower Cranes for me, I get nauseous just looking at them. LOL! Work has been pretty bad here also. We will be building a new $3.1B bridge across the Hudson starting this year to replace the old TZ bridge. The same company that built the bridge in San Fran.

 

[True Knight]

Good plan Dave. I am going to be installing a turbo. I've gathered most of the parts I need so far. Hopefully I'll make some time to get it all done in the near future...

 

[Dave Kay]

Thanks Knight, looking forward to your plans/ideas on turbo project. Myself, I haven't even begun to collect any hardware yet but the Banks system seems to be the easiest and most economical for now. Only wonder about performance, like will it will actually deliver compared to the 6.5L stock turbo, etc,. Recently though, I have read that some people did testing/comparison and there's little difference between the two mentioned systems performance-wise, but BIG difference in the install-ability, if there is such a word! Hopefully, other members may post a bit more on this as you have with your previous upgrades and let's see what's what!

Wishing a great weekend to all!

 

[Dave Kay]

Hey Wayne, glad to hear the news on the Hudson bridge project, hope all you guys can get out there and get-er-done! YUP!

Myself, I did some dirt pushing myself as an apprentice, actually 'scraped' a few dirt-jobs, for a couple of years. But I knew it was a path to bigger things and looking back now, I was always proud of whatever seemingly low grade job I did at the time, because I realized that all of that was a basic training and knowledge experience which pushed me forward and up the experience ladder, to which I am gratefully better positioned at this time in life... anyway--- all the best and wishing a Happy Paddy's Day to all the NY brothers!

 

[wayne pick]

Hea Dave, my truck seems to have a little more giddy up compared to my friends 98 6.5. It might just be the 4.56 gearing though.

 

[wayne pick]

Thanks Dave, I was typing as you were posting. Happy paddys day to all you IUOE brothers and sisters out there!

 

[Dave87]

True Knight, Thanks for all the good information. I just started my 4L80E swap, got the controller and Trans. I had the trans gone through and got it back last week. It had a couple of broken plates..... not sure what they were called exactly, they werent clutches or steels. Last night i just dropped the 400 so its on to running all the wires for the stand alone computer. What size tires are you running? My truck as it sits is turbo 6.2 on 37s. Im hoping that this will make my truck alot more highway friendly. Glad to hear that it was a worth while swap.

 

[Dave87]

Ok i see now that your running 37s. it help to READ sometimes. haha

 

[True Knight]

Yeah it was well worth it! I mean now I can (mostly) keep up with the flow of traffic. And with that turbo it should be even easier! I have gathered most of what I need for a turbo install, just need to make the time to do it.

 

[Dave Kay]

Since I last posted I've come to the conclusion that for guys running 37" tires coupled with 4L80, you're done as far as trans/gearing/ output is concerned. Turbo would be the next logical step. But I've since learned that the 6.2L Bank's setups are non-waste-gated units which, after reading TheDeiselPage guys write up, means that the Banks boost doesn't come in until around 2000rpm, something to consider.

That 2k rpm would be fine for my highway speeds but for my current setup, stock 32" tires and GV unit, when I'm off-roading my rpm's are around 1400-1800, leaving Mr. Banks with nothing much to do, mostly.

Anybody considering the Banks setup may want to look at their different rpm ranges, highway vs off-road, and plan accordingly.

 

[Keith_J]

Excellent writeup. I want to do the same on my 1031. That is a NP205 figure 8 pattern. You mentioned the machining of the adapter, this would be a must since the figure eight bolt pattern adapter is rare.

 

[PETE BALLARD]

Last option to list would be pinion ratio change. I beleive the fastest ratio available common to gm and dana would be 3.73 or another option - change to dana 60 or 70 on the rear for more ratio options available to the common manufacturer

 

[richingalveston]

TPS for 4l80e

for those looking to do the 4l80e swap, here is the throttle position sensor that I used. replaces vacuum style TPS on IP pump. I used the Dakota digital DS1 interface for the RPM signal.

 

[Keith_J]

for those looking to do the 4l80e swap, here is the throttle position sensor that I used. replaces vacuum style TPS on IP pump. I used the Dakota digital DS1 interface for the RPM signal.

NEAT!!! That is going to save time for certain plus make it far tidier under the hood. Although the the Dakota DSL-1 would be better with a gear tooth sensor instead of using the belt driven alternator tachometer output. Alternators go out, belts fail. It would work but gear tooth sensors are far more robust. Shouldn't be an issue to drill and tap the bell housing to fit the sensor.

 

[True Knight]

for those looking to do the 4l80e swap, here is the throttle position sensor that I used. replaces vacuum style TPS on IP pump. I used the Dakota digital DS1 interface for the RPM signal.

Great info!

 

[Dave87]

I used the stock 6.5 tps. has anyone tried using the 6.5 cam senor for the rpm pickup? its a 3 wire hookup so id imagine it would just be a 12 volt, ground, and the signal wire. im not sure i havnt seen anything on it really. just wondering what the thoughts are. Update on my swap trans, and everything is in just need to shorten the drive shaft and run cooler lines and figure out why i can only shift to drive. it doesn't like to shift past that point, anyone have this trouble? I didnt cut and weld the shift linkage i made an extension piece to get the length needed. Other than having a tranny jack that was to short and getting a shower of hot chips when drilling for the cross member, it went in kinda nice. had to use the dip stick tube from the 400 trans because the 4l80e tube was broke by the guy who removed it. So hopefully ill be driving my truck on tuesday..... hopefully.