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transmission upgrade?

6.5dragracer

6.5dragracer

Chevy Man...
Messages
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Location
Pasadena TX
got a 1999 gmc k3500 crew cab dually that my friend owns and he was wondering if you could take out the old 4l80e transmission and put in a 6l80e transmission????

what would he have to do and would it work???

thanks:thumbsup:
 
yeah i messed up and somehow ended up here idk how to move a thread but could u help me get to the 6.5 diesel engine category....

thanks
 
Not gonna happen. The 6L80E/6L90E trans both use an internal TCM that talks strictly over the CAN BUS for communications. As far as I know nobody in the aftermarket has developed an interface yet to make the CAN based internal TCM talk to a NON CAN BUS vehicle. CAN BUS has pretty well stumped the aftermarket as it is a proprietary GM system.
 
dude that f'en sucks so what ur saying is that i couldn't even get the tcm and make it work off of that or anything???
 
ok been serching online today and i cuaght wind of a guy working on putting a 6l90e in his 6.5 burb, i sent him a message to see where he's at on the project to see what i'm going to need...
 
6.5dragracer said:
ok been serching online today and i cuaght wind of a guy working on putting a 6l90e in his 6.5 burb, i sent him a message to see where he's at on the project to see what i'm going to need...
Click to expand...

If somebody can make an interface box to talk over the CAN BUS, it would be possible. CAN BUS has been a thorn in the side of the folks at DESTROKED as they have been trying for years now to crack it so they can market a 6 speed conversion kit.
 
Why would he want to swap to the 4L60, just beef up the existing 4L80e mine handles 23,900# GCW when hooked up to my g/n & backhoe; and 400+ Tq/200+ Hp @ rear I'm getting out of mine, add in a Heath reflash with TCC lock and you'll be better off using existing PCM control of the trans than a reworked setup for the 4L60.

In my setup I added deep pan PML that ads 3.75 extra qt trans fluid, 25K rated Deralle axillary trans cooling with electric fan, h/d clutch pack, B&M towing valve kit, billet torque converter, if you keep the trans cool the 4L80 is plenty of trans for whatever the 6.5 can put out I'm at about 22 Qt trans fluid in the system now.
 
ok with alot of reserching into swaping in a 6l90e it would be more expensive but easier to swap in a allison 1000 six speed
 
6.5dragracer said:
ok with alot of reserching into swaping in a 6l90e it would be more expensive but easier to swap in a allison 1000 six speed
Click to expand...
And the ALLISON would rob alot of HP from the 6.5 that is not required. The ALLISON takes a good chunk of power just to run it as the internals are pretty massive. The 4L80E or 4L85E is a MUCH better choice by any account. Build one up right and forget about it.
 
I've been thinking about the computer controls for the 4l80e. I have one in my 97 and it has been great. Thought if I ever came across another one it would be cool to put it in my 82 gasser. As I understand it, the 4l80e is based on the th400, so it should bolt up to the motor ok. Would it bolt up to the np 205 case as well? Somebody mentioned crossmember issues, if it's that closely related to the 400, then I'd think the crossmembers would be the same or close? Would I need to do anything other than buy a stand alone computer? Sure would be nice to get some more gear and mpgs than what the th400 offers. I'd really like to have a Gear Vendor but they are too much money for a poor boy like me.
 
Detroit Dan said:
I've been thinking about the computer controls for the 4l80e. I have one in my 97 and it has been great. Thought if I ever came across another one it would be cool to put it in my 82 gasser. As I understand it, the 4l80e is based on the th400, so it should bolt up to the motor ok. Would it bolt up to the np 205 case as well? Somebody mentioned crossmember issues, if it's that closely related to the 400, then I'd think the crossmembers would be the same or close? Would I need to do anything other than buy a stand alone computer? Sure would be nice to get some more gear and mpgs than what the th400 offers. I'd really like to have a Gear Vendor but they are too much money for a poor boy like me.
Click to expand...

If you get the correct 32 spline input, then yes the 205 will bolt up to it.
 
Detroit Dan said:
I've been thinking about the computer controls for the 4l80e. I have one in my 97 and it has been great. Thought if I ever came across another one it would be cool to put it in my 82 gasser. As I understand it, the 4l80e is based on the th400, so it should bolt up to the motor ok. Would it bolt up to the np 205 case as well? Somebody mentioned crossmember issues, if it's that closely related to the 400, then I'd think the crossmembers would be the same or close? Would I need to do anything other than buy a stand alone computer? Sure would be nice to get some more gear and mpgs than what the th400 offers. I'd really like to have a Gear Vendor but they are too much money for a poor boy like me.
Click to expand...
Only two ways to do it. Bobbie martin route using a TCM out of a van that had a Mech inj 6.5 with 4l80e. That requires knowledge of wiring , prints etc or IMHO which is better but will cost a little more money but much easier, go with a compushift controller. I have considered this for my CUCV many times but now looking more towards a nv4500 conversion. I would prefer to keep electronics out of my CUCV as it's my SHTF truck. It can withstand an EMP, can tow our camper and carries 100 gallons of fuel in the back so that should get us the f' outta dodge.
 
BTW for the original poster, IIRC Suncoast was working on an OTC Built 4l80e. That would be my choice in a heartbeat. If Suncoast can make a Dodge tranny bulletproof, imagine what they could do to an already good design like the 4l80e. GM always kicked ass on trannys.(we will omit the two big mistakes for this statement...th700r4 and slip and slide although racing guys liked those)
 
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