DMM

Going back and forth about the trans in my CTS-V since the 3/4 syncro decides to come apart and engage 4th gear while cruising in 6th...best lead so far is the Rockland Standard unit with TR6060 internals for $3500 to my door.

Forgot about test fitting the 4L80 until I tripped over the damn thing. Long story short, it actually fits better than I ever imagined it would. No idea why GM didn't do this from the factory...other than they didn't put it in any passenger vehicles.

What will be needed:
- Headers must be modified/straightened since they turn into the trans. Not too bad and any fab shop should be able to take care of this.
- The passenger side lower firewall must be massaged for clearance. A heavy hammer should take care of this.
- The electrical connector must either be replaced with something different or the floor has to be cut and boxed.
- There is plenty of clearance in the bellhousing area (save for the bottom of the passenger side firewall area)
- A standalone controller is required for an LS6. The 04/05 PCM does not have enough memory to control the 4L80E from what I have seen.
- The trans cooler lines have plenty of room.
- The OE trans crossmember can be reused with an extension bracket bolted/welded to the bottom. The 4L80 mount is about 2" further back.
- The driveshaft will have to be shortened about 1 1/2"
- Will have to get creative for a dipstick...most likely the "Lokar" universal piece or something similar.
- Source an Auto shifter from a regular CTS
- Mate the CTS shifter with a universal cable.


Here are a few pics....enjoy!








This is where the electrical connector and trans cable bracket hit the divers side of the floor/body.








This is where the bellhousing hits the bottom corner of the floor/firewall.






This is the top of the bellhousing at the top of the trans tunnel/firewall. This is where I thought most of the problems would be. Plenty of room.










Another pic of the elect connector and cable bracket which is what kept the trans from going up higher.

OneSlowV

iTrader: (2)

Bet your track time would improve alot with the 4speed.

04Vguy

iTrader: (3)

Damn looks good to bad my build has takin so ******* long and everyone coming out with **** I was tryin to do a ******* year ago. Oh well that's badass man. Hope it works like a champ. Right behind ya though

DMM

I've never been to the track in the V...always been too afraid to break something. Guess I should be past that now though lol.

I honestly though this would garner a little more attention since its been gone over so many times. Guess there's no real interest.

DMM

LOL....not doing the conversion now, just promised a bunch of peeps a while back that I'd gt this thing up in there to see how it fits. This is a winter project fo sho.

ColeGraham

iTrader: (8)

My personal feelings about this kind of swap aside...

I am honestly glad to see someone do this on here. Many guys have said they would, and never followed through. Big kudos to you DMM for this. I will be lurking to see how that thing runs.

2 questions real quick:
Why the 4L80 and not a 6 speed (6L80E or 90E) auto? (just wondering...nothing negative meant)
What did you do with the gear selector inside the cockpit? Like, how is everything hooked up or going to be hooked up?

Good luck...and once again, major props for the auto conversion.

DMM

I used the 4L80E b/c I had one laying on my shop floor for two years LOL. I am not going through with the conversion at the moment...I don't have that kind of time to spare right now. But, from the looks of it, it will be much easier than everyone thought it could be.

FYI - The 6L80/90E's are impossible to control without the OE PCM (that require 58x crank also) as every gear must fully disengage prior to shifting into the next or they will bind internally. I don't even think there are any standalone controllers available the the 6L's b/c engine torque and throttle must be reduced etc. It would be nice though. I'm sure one would fit with a little massaging as well.

DMM

A few more pics...after looking at them it didn't look as if there was as much room as I was saying. Here are a few more pics I took before I pulled it back out.


Here is the lower passenger floor/firewall I was talking about. Just barely hits, but it does.






A shot of the dipstick




A shot of the trans cooler bung...plenty of room..didn't look like it in the other pics




Since I could not get it all the way in the tunnel due to the electrical plug and cable bracket hitting the floor/trans tunnel, I got a tape to show how much room is above and on each side since it was a little hard to tell in the other pics:

Driver side from edge of trans tunnel to trans housing:



Passenger side from edge of trans tunnel to trans housing (you can see how much room the second trans cooler bung has in this pic):



Top of trans to top of trans tunnel




Proof I'm not bull-shitting everyone LOL

itsslow98

iTrader: (18)

You wont find or be able to build a 6l80 that will handle the abuse like the 4l80 will. Not to mention I dont think they make transbrake kits for the 6l80s.

Great thread OP, id like to see one installed and driving. I bet you could make the stock IRS live for longer then we think with an auto.

RADEoN

iTrader: (12)

Looks like nothing a bunch of hammer swings couldn't fix...

DarkCharisma

Given any thought to using a PCM from a Silverado?

jerrad

iTrader: (5)

PCS makes a controller with harness for around 1k. I have it in my vette and you can cotrol basically everything with your laptop.

ryridesmotox

Ahhh hammers the most useful tool in the box

Skidmarcx

It would be sweet to see this go through... Glad to see even the fitting process being considered

DMM

I think most of the allure of the V is the manual transmission...it was for me, and it seems to be for everyone else as well. I've had people next to me sitting in traffic lean out and ask if it was a manual trans...it's admittedly pretty cool.

That said...the only way to run with the big boys is to have an auto trans...so I'll probably start collecting parts as they come available to make this a reality possibly this fall or winter depending upon my work schedule. GM has a standalone trans controller for the 4L80E which was used in some of the early diesels...IIRC the controller and harness are $150-$200 brand new if still available and can be tuned with HP Tuners.

It's about time that I start on the turbo automatic car I already have

B_ROCKS_IT

Yeah I'm stuck on this issue too, it will be extremely difficult to get passed mid 10's with the manual, but I'm told that the autos will make my car **** from roll races...


I want to go tear **** up at TX2k next year, so not sure what I wanna do...

I had my eye on the TCI Sixshooter with paddle shifters: http://www.tciauto.com/tc/6x-six-spe...e-shifter.html

But dont wanna lose my roll power or ability for road track....

DMM

I thought of the same thing...but the 6x is riddled with problems and way out of my price range. There isn't really a way to keep OD from burning up when it's applied and released after every gear, which is the problem they're having. I think Jake is trying to get one going...maybe that one will be better.

B_ROCKS_IT

Thanks for the info! I figured for that price it was top notch perfection, if its not, then it is WAY outa my price range lol

Skidmarcx

Brake boost when you roll race!

itsslow98

iTrader: (18)

Nope, the car will be faster from a roll with an auto. The car will hold peak boost the entire run it will never drop even for a second. The turbo will also spool fast because of the converter.
It's an option but with the right converter spooling wont be an issue.