4l80 swap help
09-02-2015, 11:38 AM
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4l80 swap help
Im sure there are 1000 threads on this but im still a bit lost. Some say there are adapters needed, some say there aren't, etc. So as an updated version, could anybody help me figure out everything ill need to swap my 4l65 with a 4l80?
This is what im working with, its an 04 SS Silverado AWD with a D1 Procharger on 10 lbs, possibly a tiny bit of nitrous and maybe a cam in the future. The current transmission has upgraded clutchs ( a simple rebuild) and shift kit. In between gears it seems to lose a lot of rpm's and doesnt seem to stay revved up. Also, it sorta slips into gear instead of banging into gear firm at wide open throttle. 1-2 shift isnt awful, but 2-3 is getting pretty bad as far as slipping.
So my questions are, is a 4l80 even neccesary? if yes, will it need to be built, or will a stock one hold up fine? What all is needed to swap the 65 with an 80?
So if any of the transmission experts could help me out that would be fantastic, thanks guys.
This is what im working with, its an 04 SS Silverado AWD with a D1 Procharger on 10 lbs, possibly a tiny bit of nitrous and maybe a cam in the future. The current transmission has upgraded clutchs ( a simple rebuild) and shift kit. In between gears it seems to lose a lot of rpm's and doesnt seem to stay revved up. Also, it sorta slips into gear instead of banging into gear firm at wide open throttle. 1-2 shift isnt awful, but 2-3 is getting pretty bad as far as slipping.
So my questions are, is a 4l80 even neccesary? if yes, will it need to be built, or will a stock one hold up fine? What all is needed to swap the 65 with an 80?
So if any of the transmission experts could help me out that would be fantastic, thanks guys.
09-02-2015, 12:27 PM
#2
Im sure there are 1000 threads on this but im still a bit lost. Some say there are adapters needed, some say there aren't, etc. So as an updated version, could anybody help me figure out everything ill need to swap my 4l65 with a 4l80?
This is what im working with, its an 04 SS Silverado AWD with a D1 Procharger on 10 lbs, possibly a tiny bit of nitrous and maybe a cam in the future. The current transmission has upgraded clutchs ( a simple rebuild) and shift kit. In between gears it seems to lose a lot of rpm's and doesnt seem to stay revved up. Also, it sorta slips into gear instead of banging into gear firm at wide open throttle. 1-2 shift isnt awful, but 2-3 is getting pretty bad as far as slipping.
So my questions are, is a 4l80 even neccesary? if yes, will it need to be built, or will a stock one hold up fine? What all is needed to swap the 65 with an 80?
So if any of the transmission experts could help me out that would be fantastic, thanks guys.
This is what im working with, its an 04 SS Silverado AWD with a D1 Procharger on 10 lbs, possibly a tiny bit of nitrous and maybe a cam in the future. The current transmission has upgraded clutchs ( a simple rebuild) and shift kit. In between gears it seems to lose a lot of rpm's and doesnt seem to stay revved up. Also, it sorta slips into gear instead of banging into gear firm at wide open throttle. 1-2 shift isnt awful, but 2-3 is getting pretty bad as far as slipping.
So my questions are, is a 4l80 even neccesary? if yes, will it need to be built, or will a stock one hold up fine? What all is needed to swap the 65 with an 80?
So if any of the transmission experts could help me out that would be fantastic, thanks guys.
1. New crossmember
2. Shortened driveshaft or custom built one
3. Segment swap for tune
4. Wiring? (not sure about this one)
and....I'm not sure what's involved with an AWD truck either.
But you get the jist.
09-02-2015, 09:55 PM
#3
I just did this last month very successfully on my 05 Z71 and put 3000 miles on it before I tore the truck apart last week for the turbo. I used a craigslist 80e out of a 2004 8.1L Suburban (which is actually an 85e) and did a Transgo HD2 shift kit and Circle D converter at the same time, as well as a brand new TruCool transmission cooler. Dealership protocol says never to reuse a transmission cooler when replacing a transmission, and I fully agree. Very cheap insurance. The same mods for an awd SS will apply to any 4wd truck, since you'll be reusing your transfer case.
Here's a mostly complete list of what you'll need:
1. 4WD 4L80e, or 2WD 80e and associated conversion parts (tailshaft housing, etc). Much easier to start with a 4WD unit. Stock 80e's + shift kits have lived behind 1000rwhp. Be that as it may, an SSS weighs 5000+lbs and take a look at the signatures of most turbo/ blower truck owners. You'll see a lot of Jake's, FLT, and built 80e mentions. With your mods list it would be prudent of you to use a known good 80e or just send it out to get built to minimize downtime in the future and to prevent sending clutch material to your cooler and lines.
2. 32 spline transfer case input shaft. You can get these anywhere. I decided to buy a kit from Midwest Trans. I knew I was getting a high quality gear, misc seals I needed. You'll need to transfer over the inner bearing from your stock input shaft otherwise ask whoever you're getting the shaft from to sell you a new "inner bearing." You will also definitely want a case saver (they are super cheap). You can get those on eBay or Midwest Trans or anywhere. The only tool I recommend sourcing is a proper pair of flat nose snap ring pliers. You can get these at Sears. They look like this.
3. I believe you need the blue Autotrac transfer case fluid from the dealer, or . I may be wrong because you are AWD. But for the NP246 guys, the Autotrac fluid is the go-to. A bit of discussion over this but I'm the kinda guy that spends HOURS researching before even touching a wrench and I decided to get the GM fluid.
4. Segment swap (you'll need HP tuners). Very simple. Plug in HP tuners and right away it will tell you your OS #. Then google your OS and the words "4L80e segment" and you'll find one right away. There are instructions here. You'll want to basically follow this trans tuning guide word for word unless you have a tuner you trust.
5. Purchase a VSS harness from Speartech or eBay or anywhere. They usually come with instructions on which empty holes in the ECM connector they need to be plugged into. Cheapest way is to buy this connector and these pins.
6. Two wires must be repinned in the main trans connector (very easy, diagrams online, just stick a pic into the connector and then relocate 2 wires in the connector). Diagram here
7. Crossmember. Three options. Cut/ reweld stock crossmember (in my opinion that's the worst option). #2 weld a new trans mount pad to the back of your existing crossmember (which is what I did pic1, pic2 or #3 purchase aftermarket crossmember (completely unnecessary but an option for those who don't have a welding buddy or can't weld themselves). On page 3 of my build thread I have a bunch of pics of the crossmember mods I did.
8. Driveshafts. Option # 1 shorten rear shaft 1 11/16" and lengthen front shaft 1 11/16". Option #2 purchase 2500HD front shaft (others chime in with part #). I chose #1 and had new u-joints installed.
9. Slightly bend frontwards stock trans cooler line to fit front hole on 80e, use 2500HD rearward line. This is what I did initially. Or #2 option make your own braided lines, which is what I'm doing now in order to have more clearance around the downpipe area and so I can bypass the radiator. For braided lines you'll need these for the trans and these for the TruCool. You'll need [2] 90 degree -6AN fittings for the trans and [2] straight -6AN for the cooler (if you use a TruCool which I highly recommend) and about 15ft of your hose of choice.
10. Purchase other misc swap parts needed if they did not come with the trans: 80e flexplate, crossmember, dipstick, and dust cover (GM part # 15765623) I got mine here. For the flexplate you can use a 6.0L 2500HD OEM flexplate and a spacer, or any of the aftermarket offerings. I used a Circle D.
That's about it!
Here's a mostly complete list of what you'll need:
1. 4WD 4L80e, or 2WD 80e and associated conversion parts (tailshaft housing, etc). Much easier to start with a 4WD unit. Stock 80e's + shift kits have lived behind 1000rwhp. Be that as it may, an SSS weighs 5000+lbs and take a look at the signatures of most turbo/ blower truck owners. You'll see a lot of Jake's, FLT, and built 80e mentions. With your mods list it would be prudent of you to use a known good 80e or just send it out to get built to minimize downtime in the future and to prevent sending clutch material to your cooler and lines.
2. 32 spline transfer case input shaft. You can get these anywhere. I decided to buy a kit from Midwest Trans. I knew I was getting a high quality gear, misc seals I needed. You'll need to transfer over the inner bearing from your stock input shaft otherwise ask whoever you're getting the shaft from to sell you a new "inner bearing." You will also definitely want a case saver (they are super cheap). You can get those on eBay or Midwest Trans or anywhere. The only tool I recommend sourcing is a proper pair of flat nose snap ring pliers. You can get these at Sears. They look like this.
3. I believe you need the blue Autotrac transfer case fluid from the dealer, or . I may be wrong because you are AWD. But for the NP246 guys, the Autotrac fluid is the go-to. A bit of discussion over this but I'm the kinda guy that spends HOURS researching before even touching a wrench and I decided to get the GM fluid.
4. Segment swap (you'll need HP tuners). Very simple. Plug in HP tuners and right away it will tell you your OS #. Then google your OS and the words "4L80e segment" and you'll find one right away. There are instructions here. You'll want to basically follow this trans tuning guide word for word unless you have a tuner you trust.
5. Purchase a VSS harness from Speartech or eBay or anywhere. They usually come with instructions on which empty holes in the ECM connector they need to be plugged into. Cheapest way is to buy this connector and these pins.
6. Two wires must be repinned in the main trans connector (very easy, diagrams online, just stick a pic into the connector and then relocate 2 wires in the connector). Diagram here
7. Crossmember. Three options. Cut/ reweld stock crossmember (in my opinion that's the worst option). #2 weld a new trans mount pad to the back of your existing crossmember (which is what I did pic1, pic2 or #3 purchase aftermarket crossmember (completely unnecessary but an option for those who don't have a welding buddy or can't weld themselves). On page 3 of my build thread I have a bunch of pics of the crossmember mods I did.
8. Driveshafts. Option # 1 shorten rear shaft 1 11/16" and lengthen front shaft 1 11/16". Option #2 purchase 2500HD front shaft (others chime in with part #). I chose #1 and had new u-joints installed.
9. Slightly bend frontwards stock trans cooler line to fit front hole on 80e, use 2500HD rearward line. This is what I did initially. Or #2 option make your own braided lines, which is what I'm doing now in order to have more clearance around the downpipe area and so I can bypass the radiator. For braided lines you'll need these for the trans and these for the TruCool. You'll need [2] 90 degree -6AN fittings for the trans and [2] straight -6AN for the cooler (if you use a TruCool which I highly recommend) and about 15ft of your hose of choice.
10. Purchase other misc swap parts needed if they did not come with the trans: 80e flexplate, crossmember, dipstick, and dust cover (GM part # 15765623) I got mine here. For the flexplate you can use a 6.0L 2500HD OEM flexplate and a spacer, or any of the aftermarket offerings. I used a Circle D.
That's about it!
Last edited by lxcoupe; 09-12-2015 at 12:47 PM.
09-03-2015, 08:42 AM
#5
Not all of us are as talented as you! Your stuff is amazing. OP, if you're looking to buy a cross member check out his!
Otherwise you might end up with what I pieced together.... What I spent in time, equipment and pain would make his parts a $$ deal!
Otherwise you might end up with what I pieced together.... What I spent in time, equipment and pain would make his parts a $$ deal!
09-03-2015, 08:47 AM
#6
I just did this last month very successfully on my 05 Z71 and put 3000 miles on it before I tore the truck apart last week for the turbo. I used a craigslist 80e out of a 2004 8.1L Suburban (which is actually an 85e) and did a Transgo HD2 shift kit and Circle D converter at the same time, as well as a brand new TruCool transmission cooler. Dealership protocol says never to reuse a transmission cooler when replacing a transmission, and I fully agree. Very cheap insurance. The same mods for an awd SS will apply to any 4wd truck, since you'll be reusing your transfer case.
Here's a mostly complete list of what you'll need:
1. 4WD 4L80e, or 2WD 80e and associated conversion parts (tailshaft housing, etc). Much easier to start with a 4WD unit. Stock 80e's + shift kits have lived behind 1000rwhp. Be that as it may, an SSS weighs 5000+lbs and take a look at the signatures of most turbo/ blower truck owners. You'll see a lot of Jake's, FLT, and built 80e mentions. With your mods list it would be prudent of you to use a known good 80e or just send it out to get built to minimize downtime in the future and to prevent sending clutch material to your cooler and lines.
2. 32 spline transfer case input shaft. You can get these anywhere. I decided to buy a kit from Midwest Trans. I knew I was getting a high quality gear, misc seals I needed. You'll need to transfer over the inner bearing from your stock input shaft otherwise ask whoever you're getting the shaft from to sell you a new "inner bearing." You will also definitely want a case saver (they are super cheap). You can get those on eBay or Midwest Trans or anywhere. The only tool I recommend sourcing is a proper pair of flat nose snap ring pliers. You can get these at Sears. They look like this.
3. I believe you need the blue Autotrac transfer case fluid from the dealer, or online. I may be wrong because you are AWD. But for the NP246 guys, the Autotrac fluid is the go-to. A bit of discussion over this but I'm the kinda guy that spends HOURS researching before even touching a wrench and I decided to get the GM fluid.
4. Segment swap (you'll need HP tuners). Very simple. Plug in HP tuners and right away it will tell you your OS #. Then google your OS and the words "4L80e segment" and you'll find one right away. There are instructions here. You'll want to basically follow this trans tuning guide word for word unless you have a tuner you trust.
5. Purchase a VSS harness from Speartech or eBay or anywhere. They usually come with instructions on which empty holes in the ECM connector they need to be plugged into. Cheapest way is to buy this connector and these pins.
6. Two wires must be repinned in the main trans connector (very easy, diagrams online, just stick a pic into the connector and then relocate 2 wires in the connector). Diagram here
7. Crossmember. Three options. Cut/ reweld stock crossmember (in my opinion that's the worst option). #2 weld a new trans mount pad to the back of your existing crossmember (which is what I did pic1, pic2 or #3 purchase aftermarket crossmember (completely unnecessary but an option for those who don't have a welding buddy or can't weld themselves). On page 3 of my build thread I have a bunch of pics of the crossmember mods I did.
8. Driveshafts. Option # 1 shorten rear shaft 11/16" and lengthen front shaft 11/16". Option #2 purchase 2500HD front shaft (others chime in with part #). I chose #1 and had new u-joints installed.
9. Slightly bend frontwards stock trans cooler line to fit front hole on 80e, use 2500HD rearward line. This is what I did initially. Or #2 option make your own braided lines, which is what I'm doing now in order to have more clearance around the downpipe area and so I can bypass the radiator. For braided lines you'll need these for the trans and these for the TruCool. You'll need [2] 90 degree -6AN fittings for the trans and [2] straight -6AN for the cooler (if you use a TruCool which I highly recommend) and about 15ft of your hose of choice.
10. Purchase other misc swap parts needed if they did not come with the trans: 80e flexplate, crossmember, dipstick, and dust cover (GM part # 15765623) I got mine here. For the flexplate you can use a 6.0L 2500HD OEM flexplate and a spacer, or any of the aftermarket offerings. I used a Circle D.
That's about it!
Here's a mostly complete list of what you'll need:
1. 4WD 4L80e, or 2WD 80e and associated conversion parts (tailshaft housing, etc). Much easier to start with a 4WD unit. Stock 80e's + shift kits have lived behind 1000rwhp. Be that as it may, an SSS weighs 5000+lbs and take a look at the signatures of most turbo/ blower truck owners. You'll see a lot of Jake's, FLT, and built 80e mentions. With your mods list it would be prudent of you to use a known good 80e or just send it out to get built to minimize downtime in the future and to prevent sending clutch material to your cooler and lines.
2. 32 spline transfer case input shaft. You can get these anywhere. I decided to buy a kit from Midwest Trans. I knew I was getting a high quality gear, misc seals I needed. You'll need to transfer over the inner bearing from your stock input shaft otherwise ask whoever you're getting the shaft from to sell you a new "inner bearing." You will also definitely want a case saver (they are super cheap). You can get those on eBay or Midwest Trans or anywhere. The only tool I recommend sourcing is a proper pair of flat nose snap ring pliers. You can get these at Sears. They look like this.
3. I believe you need the blue Autotrac transfer case fluid from the dealer, or online. I may be wrong because you are AWD. But for the NP246 guys, the Autotrac fluid is the go-to. A bit of discussion over this but I'm the kinda guy that spends HOURS researching before even touching a wrench and I decided to get the GM fluid.
4. Segment swap (you'll need HP tuners). Very simple. Plug in HP tuners and right away it will tell you your OS #. Then google your OS and the words "4L80e segment" and you'll find one right away. There are instructions here. You'll want to basically follow this trans tuning guide word for word unless you have a tuner you trust.
5. Purchase a VSS harness from Speartech or eBay or anywhere. They usually come with instructions on which empty holes in the ECM connector they need to be plugged into. Cheapest way is to buy this connector and these pins.
6. Two wires must be repinned in the main trans connector (very easy, diagrams online, just stick a pic into the connector and then relocate 2 wires in the connector). Diagram here
7. Crossmember. Three options. Cut/ reweld stock crossmember (in my opinion that's the worst option). #2 weld a new trans mount pad to the back of your existing crossmember (which is what I did pic1, pic2 or #3 purchase aftermarket crossmember (completely unnecessary but an option for those who don't have a welding buddy or can't weld themselves). On page 3 of my build thread I have a bunch of pics of the crossmember mods I did.
8. Driveshafts. Option # 1 shorten rear shaft 11/16" and lengthen front shaft 11/16". Option #2 purchase 2500HD front shaft (others chime in with part #). I chose #1 and had new u-joints installed.
9. Slightly bend frontwards stock trans cooler line to fit front hole on 80e, use 2500HD rearward line. This is what I did initially. Or #2 option make your own braided lines, which is what I'm doing now in order to have more clearance around the downpipe area and so I can bypass the radiator. For braided lines you'll need these for the trans and these for the TruCool. You'll need [2] 90 degree -6AN fittings for the trans and [2] straight -6AN for the cooler (if you use a TruCool which I highly recommend) and about 15ft of your hose of choice.
10. Purchase other misc swap parts needed if they did not come with the trans: 80e flexplate, crossmember, dipstick, and dust cover (GM part # 15765623) I got mine here. For the flexplate you can use a 6.0L 2500HD OEM flexplate and a spacer, or any of the aftermarket offerings. I used a Circle D.
That's about it!
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09-03-2015, 11:08 AM
#8
Bad news on #2. The 32 spline input shaft that can be purchased from a lot of places for about $50 will not work. There is only one place to get the input shaft for the 149 transfer case and it'll cost you about 10X as much as the one for the 246 lol....sucks, I'm about to have to buy one too.
