4l80. Is it worth it? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

SunSoaked · 07-24-2019, 10:32 AM

A guy near me wants to sell me a 98 2500 HD. Has a 454, t-case and 4180 that runs but probably needs rebuilt. He'll take $1000 for the truck but it's a parts deal only due to title issue. All I want is the trans to swap in place of my 400.
Are these good trans to start with? I'll use an aftermarket controller.

**mongocanfly** · 07-24-2019, 01:06 PM

The 4l80 is the replace for the t400...just has od.....good trans....
But there is a difference....are you putting it in a 2wd or 4wd?...

sweetk30 · 07-24-2019, 01:40 PM

same gear ratios as you have just overdrive and lockup .

there longer so requires drive shaft re-work / move the crossmember / shifter linkage / what t-case ? this is very important as to the way it will hook up .

th400 back of the case is a slightly different size than the 4l80 but the bolt holes are the same except metric i think . but you can NOT simply bolt a th400 adapter to a 4l80 for a few reasons .

whats going to control the trans ? its full electric . there is www.usshift.com they make a solid unit with lots of options and its stand alone and 4wd compatible . and the 4l80 requires 2 speed sensors so its run as a 2wd and make sure the guts inside on rebuild are setup for the rear sensor tone ring or modify the t-case for electric speedo or some sort of adapter .

SunSoaked · 07-24-2019, 03:01 PM

I was just wondering if there were issues with certain model years. It appears that it's not going to be cost effective. The 454 convertor won't work with my 350, needs rebuilt, needs a controller, adapter, etc and still needs driveshaft mods. I guess I'll just wait till the heat let's up and move forward with the 4500 conversion.
Thanks

**kwmech** · 07-25-2019, 12:19 PM

Doing the swap at the moment in my 91 burb. Taking out the 700 and putting the 4l80. If you are replacing a T400, it would be easier to get an earlier trans as the cooler lines changed in 96/97ish. A 92-96 core works out better for the cooler lines and there were a few other changes in the later models. I got the US shift controller and am wiring in for the speedo correction. found a decent spot to mount it in the side of the glove box with velcro strips. Found the spot in the firewall where the factory 4l80e harness passed through. Had to pull out the heater core box to access and drill for the harness.. Hope to be driving it in a week or 2

07-24-2019, 10:32 AM	#1
SunSoaked Registered User Join Date: Dec 2011 Location: Yuma Arizona Posts: 1,524	4l80. Is it worth it? A guy near me wants to sell me a 98 2500 HD. Has a 454, t-case and 4180 that runs but probably needs rebuilt. He'll take $1000 for the truck but it's a parts deal only due to title issue. All I want is the trans to swap in place of my 400. Are these good trans to start with? I'll use an aftermarket controller.

07-24-2019, 01:06 PM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,585	Re: 4l80. Is it worth it? The 4l80 is the replace for the t400...just has od.....good trans.... But there is a difference....are you putting it in a 2wd or 4wd?... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

07-24-2019, 01:40 PM	#3
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: 4l80. Is it worth it? same gear ratios as you have just overdrive and lockup . there longer so requires drive shaft re-work / move the crossmember / shifter linkage / what t-case ? this is very important as to the way it will hook up . th400 back of the case is a slightly different size than the 4l80 but the bolt holes are the same except metric i think . but you can NOT simply bolt a th400 adapter to a 4l80 for a few reasons . whats going to control the trans ? its full electric . there is www.usshift.com they make a solid unit with lots of options and its stand alone and 4wd compatible . and the 4l80 requires 2 speed sensors so its run as a 2wd and make sure the guts inside on rebuild are setup for the rear sensor tone ring or modify the t-case for electric speedo or some sort of adapter . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

07-24-2019, 03:01 PM	#4
SunSoaked Registered User Join Date: Dec 2011 Location: Yuma Arizona Posts: 1,524	Re: 4l80. Is it worth it? I was just wondering if there were issues with certain model years. It appears that it's not going to be cost effective. The 454 convertor won't work with my 350, needs rebuilt, needs a controller, adapter, etc and still needs driveshaft mods. I guess I'll just wait till the heat let's up and move forward with the 4500 conversion. Thanks

07-25-2019, 12:19 PM	#5
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,391	Re: 4l80. Is it worth it? Doing the swap at the moment in my 91 burb. Taking out the 700 and putting the 4l80. If you are replacing a T400, it would be easier to get an earlier trans as the cooler lines changed in 96/97ish. A 92-96 core works out better for the cooler lines and there were a few other changes in the later models. I got the US shift controller and am wiring in for the speedo correction. found a decent spot to mount it in the side of the glove box with velcro strips. Found the spot in the firewall where the factory 4l80e harness passed through. Had to pull out the heater core box to access and drill for the harness.. Hope to be driving it in a week or 2



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