07-08 4L60e to 6L80e swap
12-19-2017, 02:03 PM
#341
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sorry for the delay what have done is put a 6l80e in place of a 4l80 that it already ahead a 6.2l swap so I used the harness from the 6.0l and plugged everything up and turned the key and nothing haven't programmed anything yet waiting for a 2007 Tcm for a 6l80
02-10-2019, 12:14 AM
#344
Ok, I’ve read the first few pages on the OP’s swap and have a few of my own.
i have an 08 Avalanche 2wd 5.3/4l60e, sifting at 97K miles and no issues other than occasional lifter tick on cold starts.
i have a 2010 6l80e I picked up for 350 bucks with 114K miles and got the 2010 Tahoe 5.3/6l80e harness and pcm with it. I have a brand new ZL1 twin disk 2000-2400 stall converter for it as well. Now the Tahoe the trans and harness are from was a 4wd, but I have the camaro extension housing for the trans to make my 4wd trans a 2wd and will get a short 4l80e yoke for the front driveshaft. Mine being 2wd it has a 2 piece shaft so I know how to handle that part.
My main question was with the trans crossmember and will my stock one fit or do I need one from an 09+ that came with the 6l80? From what I’ve seen on official dimensions the 6l and my stock 4l are very close as far as the trans mount is concerned. I’m going to just get stock 09 6l trans cooler lines that should fit my stock radiator, and mine has the aux trans cooler as well. I know I’ll have to get it all tuned as well.
Im going to be pulling the engine and trans once it warms up to do mechanical DOD delete and cam upgrade on the engine and figure it’s a good time to go back in with the 6sp. I also have a 2010 6.2 that is a non DOD and I’ve deleted VVT with an LS3 430HP cam that I am considering putting back in the truck, I have speed engineering 1 3/4 LT’s and ORY I bought for the 5.3 and the truck already has a Dynomax Ultra Flo catback Kit And Volant CAI on it.
Thanks for the help and info on this swap, also my truck has stock 3.73 gears and I know the 09+ trucks all seem to run 3.42 stock, I am thinking 3.23 would be a good setup to still get good acceleration out of the hole and a chance at decent MPG on the highway with the .66 OD of the 6sp.
i have an 08 Avalanche 2wd 5.3/4l60e, sifting at 97K miles and no issues other than occasional lifter tick on cold starts.
i have a 2010 6l80e I picked up for 350 bucks with 114K miles and got the 2010 Tahoe 5.3/6l80e harness and pcm with it. I have a brand new ZL1 twin disk 2000-2400 stall converter for it as well. Now the Tahoe the trans and harness are from was a 4wd, but I have the camaro extension housing for the trans to make my 4wd trans a 2wd and will get a short 4l80e yoke for the front driveshaft. Mine being 2wd it has a 2 piece shaft so I know how to handle that part.
My main question was with the trans crossmember and will my stock one fit or do I need one from an 09+ that came with the 6l80? From what I’ve seen on official dimensions the 6l and my stock 4l are very close as far as the trans mount is concerned. I’m going to just get stock 09 6l trans cooler lines that should fit my stock radiator, and mine has the aux trans cooler as well. I know I’ll have to get it all tuned as well.
Im going to be pulling the engine and trans once it warms up to do mechanical DOD delete and cam upgrade on the engine and figure it’s a good time to go back in with the 6sp. I also have a 2010 6.2 that is a non DOD and I’ve deleted VVT with an LS3 430HP cam that I am considering putting back in the truck, I have speed engineering 1 3/4 LT’s and ORY I bought for the 5.3 and the truck already has a Dynomax Ultra Flo catback Kit And Volant CAI on it.
Thanks for the help and info on this swap, also my truck has stock 3.73 gears and I know the 09+ trucks all seem to run 3.42 stock, I am thinking 3.23 would be a good setup to still get good acceleration out of the hole and a chance at decent MPG on the highway with the .66 OD of the 6sp.
04-06-2019, 12:45 PM
#346
04-06-2019, 01:15 PM
#347
So I have done this on my 2007 tahoe. Some key notes on this setup. Ecm on 2007-2008 already run the correct os in it if you look up a 2007 cadillac or gmc with a 6.2 and the 6l80e in it they run the same os. So if you buy a used trans and going to run it as is then you want to buy a 2007 or 2008 to be safe I would match the trans year to the truck ecm year even thought the tcm will work on a few more years. The tcm year breaks is 2007-2009 you can program any year into that part number. then the 2007-08 ecm will use the same os. The 2009 ecm has a different os its actually better but I do not know if you can write it into an early one with out bricking the ecm. Some say the trucks will work but read a 2007 corvette e38 if you write a 2009 corvette os into it that it will brick and be done. I know what work with what on these as I worked at a trans shop and we were mixing up certain years to fit others to send them to customers. Keep in mind of you buy a 2013 trans and think your going to put a 2009 tcm in it to work with your 2009 ecm its not going to work. The tcm matches the valve body on these and why you need to plan out your transmission part number purchase to be the correct year to not run into issues.
I have been having some weird issues on mine loss of communication to the bcm from tcm. YES this trans does look to the bcm for somethings. When I lose the connection and code sets I get no torque signal and it slams on the shifts and even will move shift points around. Guys doing swaps to early vehicles are using relays and resistors to get around the bcm functions on the swaps and its a handful to get it to act right vrs builds like these where the bcm is still in tact. SO if you have a code on bcm to tcm communications u0140 or u0110 its going to act weird.
I have a 2007 tahoe with the correct 2007 ecm I am using the 2007 os in the trans wrote from a 2008 gmc denail with a 6.2/6l80e thats how I wrote the correct os to the new tcm. BUT I first started with an old tcm that was used and wrote it was out of a 2007 cadillac escalade and after I got this stupid 2009 silverado harness all re pinned and pinned my old transfer case harness into that big black plug it all worked but not right. It would drive and shift but was erratic due to this bcm problem i think anyway its that or I have missed something in the wiring swap. I am in the process of trying to make the tow haul and prnd321 setup to the right stuff. The tow haul is turning on at the dash but its not seeing it at the transmission. So I just wrote a 2009 tahoe bcm os into a used bcm I got and hoping that it was going to straighten this all out and no luck. Tow haul isnt at trans still and head didnt change the prndl321 to the prndm. So thinking I can now try to write a 2007 caddy escalade speedo calibration into my current 07 head and think that will not only fix the prndl but make the tow haul work as the wiring is there and bcm is setup now for a 2009 that has a 6l80 setup in it. If that dont work then must be something Im missing in the wiring. After this is done then will try to make the tap up and down work out right. I had thought of just buying a 2009 and up tahoe speedo cluster with it already programmed but this is free to try vrs buying one.
One thing I now dont have is the current tcm u0140 code in the trans so the bcm 2009 write I did to it has given me some more communication from the bcm to the tcm. SO part of this issue is now fixed. I was about to just write 2009 everrything into it the ecm the tcm bcm and cluster but I do drive it daily so not wanting to fry anything Im going one step at a time to see what will be fixed before going to extremes. Mine has a blower on it too so my tune is far from working with any stock os so that process will take a while to setup just to find it did nothing to help the trans work as it should.
The other thing I see is my input and output speeds on the scanner never get to 1:1 with lock up on. So that is telling me the input speed is skewed and the fact the engine rpm is off from the input speed thats also a sign. I have played with a few output settings 40/40 40/36 and now 36/36 as the reluctor in the 6l is 36 tooth count so that should be correct but still wont shift at my commanded 5400-5600 rpm at wot it willl just go to the rev limit sometimes or it has this weird hesitation on the shift. Has a mind of its own sometimes hard shifts or late even the stupid tcc will lock up in 3rd then unlock then lock back in 4th and I have even commanded it to only lock up in 5th and 6th. So I have something really weird going on when it acts up. Sometimes it drives pretty normal and think its when it sets these weird codes it will act up as when I do a full write on the ecm and tcm it will act fine for a little while.
Just trying to put more info out there for others to also read up on and possibly stumble on someone that had issues and fixed it. Ill post up if this speedo head write does anyting good for me or not.
I have been having some weird issues on mine loss of communication to the bcm from tcm. YES this trans does look to the bcm for somethings. When I lose the connection and code sets I get no torque signal and it slams on the shifts and even will move shift points around. Guys doing swaps to early vehicles are using relays and resistors to get around the bcm functions on the swaps and its a handful to get it to act right vrs builds like these where the bcm is still in tact. SO if you have a code on bcm to tcm communications u0140 or u0110 its going to act weird.
I have a 2007 tahoe with the correct 2007 ecm I am using the 2007 os in the trans wrote from a 2008 gmc denail with a 6.2/6l80e thats how I wrote the correct os to the new tcm. BUT I first started with an old tcm that was used and wrote it was out of a 2007 cadillac escalade and after I got this stupid 2009 silverado harness all re pinned and pinned my old transfer case harness into that big black plug it all worked but not right. It would drive and shift but was erratic due to this bcm problem i think anyway its that or I have missed something in the wiring swap. I am in the process of trying to make the tow haul and prnd321 setup to the right stuff. The tow haul is turning on at the dash but its not seeing it at the transmission. So I just wrote a 2009 tahoe bcm os into a used bcm I got and hoping that it was going to straighten this all out and no luck. Tow haul isnt at trans still and head didnt change the prndl321 to the prndm. So thinking I can now try to write a 2007 caddy escalade speedo calibration into my current 07 head and think that will not only fix the prndl but make the tow haul work as the wiring is there and bcm is setup now for a 2009 that has a 6l80 setup in it. If that dont work then must be something Im missing in the wiring. After this is done then will try to make the tap up and down work out right. I had thought of just buying a 2009 and up tahoe speedo cluster with it already programmed but this is free to try vrs buying one.
One thing I now dont have is the current tcm u0140 code in the trans so the bcm 2009 write I did to it has given me some more communication from the bcm to the tcm. SO part of this issue is now fixed. I was about to just write 2009 everrything into it the ecm the tcm bcm and cluster but I do drive it daily so not wanting to fry anything Im going one step at a time to see what will be fixed before going to extremes. Mine has a blower on it too so my tune is far from working with any stock os so that process will take a while to setup just to find it did nothing to help the trans work as it should.
The other thing I see is my input and output speeds on the scanner never get to 1:1 with lock up on. So that is telling me the input speed is skewed and the fact the engine rpm is off from the input speed thats also a sign. I have played with a few output settings 40/40 40/36 and now 36/36 as the reluctor in the 6l is 36 tooth count so that should be correct but still wont shift at my commanded 5400-5600 rpm at wot it willl just go to the rev limit sometimes or it has this weird hesitation on the shift. Has a mind of its own sometimes hard shifts or late even the stupid tcc will lock up in 3rd then unlock then lock back in 4th and I have even commanded it to only lock up in 5th and 6th. So I have something really weird going on when it acts up. Sometimes it drives pretty normal and think its when it sets these weird codes it will act up as when I do a full write on the ecm and tcm it will act fine for a little while.
Just trying to put more info out there for others to also read up on and possibly stumble on someone that had issues and fixed it. Ill post up if this speedo head write does anyting good for me or not.
04-06-2019, 04:10 PM
#348
ok so I tried putting 3 or 4 programs in the cluster and no go its staying prnd321 so this must 100 percent be part of that gauge cluster. I also put 3 in the bcm and just managed to lock out the radio and get an air suspension message as I tried both 2007 escalade and denail and a 2008 suburban 2500 6.0 6 speed vin. The issue on the bcm seems to be they added more options from 2007 to 2009. it has to be a suv or it will lose the lift gate function and the rear two windows with some vin. I am going to buy a 2009 gauge cluster and put that in and that will setup the prndm and while its not needed I just wanted to do it and have it show up as it should. Still dont get why the tow haul isnt working on iit as its reporting it to the cluster the light comes on but viewing it with the tech2 its not switching. And I just noticed its reporting the brake switch as applied even when Im not pushing on the brake and I have verified that its working fine. Actually hptuners is reporting it as working correctly on and off but gm mdi2 tech2win is showing it as staying pushed like riding the brakes so sure thats not good on the converter trying to lock up and maybe why its coming and going in gears it shouldnt be. Anyway dont bother with the bcm change so far or the gauge cluster stuff. I do see a grey wire that is reported to go to the fpcm and fuel pressure positive wire and the 07 suv doesnt use them like the 2007 trucks do. so that being open could be an issue too as its needing + voltage on that wire some reason. Going to have to dig more on this and maybe delete the bcm stuff from it and wire it up as if it was a hotrod to make it work right.
04-08-2019, 06:23 AM
#349
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Thanks for the reply
I actually repinned my new harness last Tuesday but haven’t had time to install motor and transmission yet. The extra wires that had me worried turned out to all be the 4wd wiring. Just a thought on the brake switch switching back and forth. I had a 2008 truck come into the shop awhile back and was doing the same thing. Brake lights worked it would come outta park fine but turned out to be a bad switch.
07-05-2019, 03:44 PM
#350
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Just FYI, the 6 speed clusters are different than the 4 speed clusters, you just need to make sure you get one out of a 6 speed with similar options as yours. They are interchangable but the gear indicator just won't work if you say, put a 6 speed cluster in a 4 speed truck. The screens in the clusters are vfd, so they can only display what they're made to display.
