Th400 to 4l80e Swap - Pirate4x4.Com : 4x4 and Off-Road Forum

lisaontherocks · 10-10-2010, 12:17 AM

I am considering swapping the th400 to a 4l80e in my 88 suburban 3/4 ton. I have been told you can repin the ECM for speed senor and that the tcase adapter will bolt right up. Has anyone done this? did you run into any major issues?

LS1_CJ · 10-11-2010, 04:48 AM

i'm pretty sure the pcm won't control the 4l80e. later model trucks it can be done, but it still requires a 4l80 transmission tune to be flashed into the pcm. I think your choices will be a manual valve body or a stand alone controler

confederate muscle · 10-11-2010, 04:55 AM

far as i know, re pinning the harness was only between a 4l60e/4l80e transmission

LS1_CJ · 10-11-2010, 05:11 AM

Quote:

Originally Posted by confederate muscle

far as i know, re pinning the harness was only between a 4l60e/4l80e transmission

this.... 99 and up can be done, don't think the tbi can do it

BigBlocksRule · 10-11-2010, 07:24 AM

The harness won't have the correct plug on the end of it, the big plug started in '93 with the first 4L60E. Yours just has the 4-pin plug for TC lock-up. The TBI box can handle it - at least the correct one can. The 4L80E was first available in '91 with the 454SS truck, it was TBI.

MaXXis85 · 10-11-2010, 09:13 AM

Quote:

Originally Posted by confederate muscle

far as i know, re pinning the harness was only between a 4l60e/4l80e transmission

Yes. Not much different from 60e-80e harness plug. Do aways with one wire, swap a couple, and add one wire for the extra VSS that the 80e requires. THis is for 96+ vortecs. Bggrnchvy di the 60-80e swap and it was fairly simple to make it happen.

I am not certain how the wiring was on the TBI's with an 80e.

genebingaman · 10-11-2010, 10:09 AM

4l80 was available in 91 not only the 454ss trucks had them there is a supposed 4l80/ 205 combo for that year aswell
long story short there is a factory tbi pcm that will control the 4l80
best bet is one from 91-93
94-95 will work but there is something funky about the harness (extra plug)iirc

kenbo53 · 10-11-2010, 10:58 AM

Quote:

Originally Posted by BigBlocksRule

The harness won't have the correct plug on the end of it, the big plug started in '93 with the first 4L60E. Yours just has the 4-pin plug for TC lock-up. The TBI box can handle it - at least the correct one can. The 4L80E was first available in '91 with the 454SS truck, it was TBI.

The 454ss came with a turbo400.

angryblack · 10-11-2010, 02:06 PM

What about adapting a chevy van harness..I just scrapped the company van with a nblow 4l80e and tbi 350.. It was a 93

i would think the ecm harness and the vans pcm harness isnt that much different..

mog-10 · 10-11-2010, 04:31 PM

my 4l80e that i have was behind a 93 454 tbi it has an extra computer to control the trans

any ways the easy way of swaping it is getting a vacume modulator kit for the 4l80e

cant beat $115

http://cgi.ebay.com/ebaymotors/Trans...Q5fAccessories

BigBlocksRule · 10-12-2010, 09:10 AM

Quote:

Originally Posted by kenbo53

The 454ss came with a turbo400.

Only in '90, they had the 4L80E in '91 - '93.

and that vacuum modulator kit is a band-aid for a supposed 4L80E problem, it will NOT take the place of the computer. You can get a full manual valve body, but you totally lose automatic shifting.

It should be easy enough to junkyard source a '91 - '95 harness and ECM for the TBI and 4L80E, take care of everything at once.

kenbo53 · 10-12-2010, 10:24 AM

^ I am corrected sorry bout that

mog-10 · 10-12-2010, 11:07 AM

Quote:

Originally Posted by BigBlocksRule

Only in '90, they had the 4L80E in '91 - '93.

and that vacuum modulator kit is a band-aid for a supposed 4L80E problem, it will NOT take the place of the computer. You can get a full manual valve body, but you totally lose automatic shifting.

It should be easy enough to junkyard source a '91 - '95 harness and ECM for the TBI and 4L80E, take care of everything at once.

dont the mvb come with this in the kit to control line presure.

i have not done it my self but i have read over on ls1tech about many members using it to take place of the ecm and it shifts like a normal trans would after proper instlation with out a mvb

BigBlocksRule · 10-12-2010, 12:31 PM

The LS1 boys all have computers in their cars that handle the 4L80E, all the vac modulator does is changes shifting/holding. Believe me, if you could control one of these without the computer, the 5 cores I have would be worth a lot more than $500 apiece!

crane_guy · 10-12-2010, 03:37 PM

Quote:

Originally Posted by mog-10

my 4l80e that i have was behind a 93 454 tbi it has an extra computer to control the trans

any ways the easy way of swaping it is getting a vacume modulator kit for the 4l80e

cant beat $115

http://cgi.ebay.com/ebaymotors/Trans...Q5fAccessories

can you explain this ? i thought only 1991 1ton diesel with 4l80e had that stand alone computer ?

jd8420 · 10-12-2010, 04:41 PM

You will also need an adapter (GM part #15724745). I thihk it lists for $71.38. TH400 and 4L80E transmissions have the same bolt patern but a different sized indexing ring. Also your stock adapter would hit the oil pan of your 4L80E. I would recomend Compushifts controller. It's not the cheapest but it works very good and does not require a laptop to program it. The cheapest i have seen it is $1100 (with the display) on Ebay.

mog-10 · 10-12-2010, 06:41 PM

Quote:

Originally Posted by crane_guy

can you explain this ? i thought only 1991 1ton diesel with 4l80e had that stand alone computer ?

it is what the guy told me when i bought it he asked if i wanted it i said no he swaped over a nv4500 so he said he was not going to need it.

10-10-2010, 12:17 AM	#1 (permalink)
lisaontherocks Registered User Join Date: Mar 2008 Member # 110282 Location: c.c. colorado Posts: 14	Th400 to 4l80e Swap I am considering swapping the th400 to a 4l80e in my 88 suburban 3/4 ton. I have been told you can repin the ECM for speed senor and that the tcase adapter will bolt right up. Has anyone done this? did you run into any major issues?

10-11-2010, 04:48 AM	#2 (permalink)
LS1_CJ Registered User Join Date: Aug 2006 Member # 78137 Location: Pearland, Tx Posts: 57	i'm pretty sure the pcm won't control the 4l80e. later model trucks it can be done, but it still requires a 4l80 transmission tune to be flashed into the pcm. I think your choices will be a manual valve body or a stand alone controler __________________ 1980 CJ5 LS1, 4l60e, dana 300, mild suspension work, 35's 2007 Sierra, Fabtech, 35's, Bolt-ons

10-11-2010, 04:55 AM	#3 (permalink)
confederate muscle Granite Guru Join Date: Jan 2005 Member # 42023 Posts: 512	far as i know, re pinning the harness was only between a 4l60e/4l80e transmission __________________ 2007.5 2500HD 6.0/6l90e/241/d60/gm14 1988 V30 Crew Dually 454/400/205/D60/D70hd

10-11-2010, 02:06 PM	#9 (permalink)
angryblack Rock God Join Date: Sep 2009 Member # 142394 Location: Do or die bed stuy brooklyn Posts: 2,422	What about adapting a chevy van harness..I just scrapped the company van with a nblow 4l80e and tbi 350.. It was a 93 i would think the ecm harness and the vans pcm harness isnt that much different.. __________________ Unfortunately there is no end to human stupidity -- making things foolproof only creates more ingenious fools

10-12-2010, 10:24 AM	#12 (permalink)
kenbo53 Registered User Join Date: Mar 2010 Member # 156629 Posts: 22	^ I am corrected sorry bout that Last edited by kenbo53; 10-12-2010 at 10:31 AM.

10-11-2010, 07:24 AM	#5 (permalink)
BigBlocksRule Registered User Join Date: Mar 2009 Member # 131479 Location: Lubbock, TX Posts: 15	The harness won't have the correct plug on the end of it, the big plug started in '93 with the first 4L60E. Yours just has the 4-pin plug for TC lock-up. The TBI box can handle it - at least the correct one can. The 4L80E was first available in '91 with the 454SS truck, it was TBI.

10-11-2010, 10:09 AM	#7 (permalink)
genebingaman Registered User Join Date: Mar 2010 Member # 157094 Posts: 132	4l80 was available in 91 not only the 454ss trucks had them there is a supposed 4l80/ 205 combo for that year aswell long story short there is a factory tbi pcm that will control the 4l80 best bet is one from 91-93 94-95 will work but there is something funky about the harness (extra plug)iirc

10-11-2010, 04:31 PM	#10 (permalink)
mog-10 Registered User Join Date: Dec 2009 Member # 147891 Location: Welches oregon Posts: 1,086	my 4l80e that i have was behind a 93 454 tbi it has an extra computer to control the trans any ways the easy way of swaping it is getting a vacume modulator kit for the 4l80e cant beat $115 http://cgi.ebay.com/ebaymotors/Trans...Q5fAccessories

10-12-2010, 12:31 PM	#14 (permalink)
BigBlocksRule Registered User Join Date: Mar 2009 Member # 131479 Location: Lubbock, TX Posts: 15	The LS1 boys all have computers in their cars that handle the 4L80E, all the vac modulator does is changes shifting/holding. Believe me, if you could control one of these without the computer, the 5 cores I have would be worth a lot more than $500 apiece!

10-12-2010, 04:41 PM	#16 (permalink)
jd8420 Cotton Farmer Join Date: Aug 2010 Member # 167491 Location: Roby Texas Posts: 92	4l80 swap You will also need an adapter (GM part #15724745). I thihk it lists for $71.38. TH400 and 4L80E transmissions have the same bolt patern but a different sized indexing ring. Also your stock adapter would hit the oil pan of your 4L80E. I would recomend Compushifts controller. It's not the cheapest but it works very good and does not require a laptop to program it. The cheapest i have seen it is $1100 (with the display) on Ebay.

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