johanh13

Hello you all,

I have a 2005 GMC Sierra 2500HD SLT Crewcab shortbed 4X2 with the 6.0 Liter and 4L80 transmission and 4.1 gears. I would love to swap in a 6L90 transmission, what parts would I need to make everything work like it should?

Any help would be greatly appreciated!

PS. I had a 2003 model just like this with the 6.6 diesel and 3.73 gears, however, I prefer the gas engine (I do no towing whatsoever)...

Coban

iTrader: (14)

The parts don't exist yet. There is no way to control the electronics of the 6l90e/80e.

MNC5

One way would be to add a new ECM and wiring harness from a 2007.5 HD2500 as they cam with the 6.0 and 6L90e. Not sure how that would affect your gauges though.

Or you could check with Mast Motorsports I think they make a stand alone controller for the 6L80-90 series. And didn't SpearTech have a pickup running a 6L80 with there wiring harness and program a couple of years ago.

quicksilverado

iTrader: (8)

Speartech was working on a stand alone pcm, but I don't think they ever got all the bugs worked out.

FLT

iTrader: (1)

I would take a 4l80e over the 6l80 series transmissions any day. Just my 2 cents. Vince B

fastnblu

iTrader: (2)

I'd possibly look to MAST also (along w/. Speartech) since they seem to have already embraced some of the latest tech, i.e. VVT cams. Ya, Speartech had a project truck. I forgot what motor, but IIRC, they had to use electronics from both original truck & the CAN or BUS( whichever 1 of the 2 is the right name). Piggybacked. I wouldn't say it's easy, but w/. enuff work & the right people, I think it's doable. The 4L80E has already proven itself & has the aftermkt. support. The 6LxxE can't say that, yet.

Kerr

I to want do this swap on my 8.1L

I gave up looking a few years ago but i noticed last month that TCI is advertising a 6L90E with computer harness for hot rods... You might be able to go that rought.

Looks like the trans and computer about $6K.... e mail and see what they say then post the info

http://www.tciauto.com/products/6x/

fastnblu

iTrader: (2)

Then do it.
I don't recall TCI callin it a 6L90E, they just call it a 6X.

I remember when I saw TCI came to the market w/. the 6X. I was so excited, til I saw the price. Even the tranny alone is alot of $$$. So the hunt continues.

MNC5

From a strength standpoint I'd agree. You guys need to get up to speed on the new tranny's though. The 4L60 series is near dead from a manufacturing standpoint.

fastnblu

iTrader: (2)

Who needs to get up to speed?

4L60E has so many out there. It's weaknesses have been attempted to be rectified by the aftermkt. Problem is tho, no one has a retrofit for older stuff. At least not w/o. spending a shitload. The 80E is strong & doesn't use new style ( CAN or BUS) electronics, & therefore is more easily adapted to the weak 60e.
I wish GMPP or a whole lot of others bring a solution to poppin a 6 spd auto into older trucks. And make it reasonable too.