Questions on the 4L80E and 6L80E transmissions

[Woofwagon]

As you are aware, I'm installing at 500+ inch Cadillac engine in my '89 Suburban. I have a great Th400 in there now, but would eventually like an overdrive. This leads to a few questions.

1. Is the bellhousing pattern the same between the TH400/4L80E/6L80E? If so that will be awesome as I can get an adapter between the Caddy BOP pattern and the Chevy TH400 pattern for about $60.

2. Transfer case. If and when I go to a 4L or 6L, I will be needing a transfer case with a passenger side drop. I think there is an NP205 on the TH400 now, and I would like to keep it as it's a very strong case from what I've heard. Who makes an adapter between this case and the 4L/6L transmission?

3. Controller. Is it possible or even recommended to run the 4L or 6L without electronic control or is it an electric solenoid transmission? Looking at controller prices made me gulp a bit.

Thanks for any previous experiences you've had on these very strong transmissions.

Woofwagon

 

[KMW-NW]

I can't speak to the bolt patterns, but those are both electronic transmissions. The "E" on 4L80E actually stands for electronic. I am not sure, but I think the extent of the electronic control depends on what year vehicle it is out of. The newer it is the more dependent they became on the computer.

Sounds like an awesome build though!

 

[Woofwagon]

Yeah I knew about the "E" part. Since the transmission has electric servos controlled by a computer, I'm not sure I could run one without a computer.

 

[MotoDave]

I've found the Novak website pretty useful for engine/transmission/t-case info, and they may even sell the adapter you need.

http://www.novak-adapt.com/knowledge/4l60e.htm

 

[Ridge Runner]

1. Yes.

2. You need a GM T-case with a 32 spline input. Your NP205 might actually fit.

 

[warwgn]

as long as your TH400 has a 32 spline out put shaft then what ever you can bolt to it will bolt to the 4L80E, I would not bother with the 60E go straight for the big dog. Now as for bolting to the engine, yes if a TH400 works then they will work.

Ok for the computer stuff, Hughes Performance offers the 80E with a full manual valve body so no computer, but you only save about 100 bucks or so I think. I went with Jakes Performance, and the controller, the trans, and torque converter came in at $3850.00, no core charge and built with a warranty for up to 750 HP.

The controller was like 500 I think, and came with everything needed, even the TPS (although it was for an edelbrock or Holley, but I had a remote mount already) and it is way easy to install and program, and has lots of cool options. I would recommend doing that vs full manual valve body.

If you find an old one ton truck not sure which years, but still old body style they came with 4l80E so you could pull the brain and harness out and prolly use that for much cheaper, especially if you go TBI you can get it all in one shot. Hope that helps.

 

[Larry]

Forget about the 6L80/90. They are completely different animals from the 4L60E and 4L80E. I have not seen any sources of stand-alone controllers for the 6L’s. The 6L is an odd deal where the trans controller is actually part of the valve body. They call it a control valve assembly. The only way to run a 6L that I know of is in conjunction with a late model the Gen IV engine using the 58x crank trigger ECM input using all GM electronics. I’m sure the aftermarket will eventually catch up to the 6L but they may skip it all together as the new 2015 8L80/90 will have an external TCM, which may be easier for the aftermarket to support….Time will tell. 6 or even 8 cogs are too many in my opinion anyway. All those extra cogs do is create heat and shift busyness. Its not like us guys are adding gears to meet CAFE standards with our big junk.

4L80E's are pretty well supported and can be built to handle a lot of power with tons of aftermarket support. I built a little 1993 1/2 ton Sportside with a TBI 7.4L. I did the 5 speed manual to an automatic a year after the BB swap so the trans had to run on its own controller which I used a TCI Ez-Shift TCM and it works very well.

 

[superbuickguy]

there are controllers for the 6L80e (e.g. http://zerogravityperformance.com/6l80e-stage-1/) whatever you do, don't mistake the TCM transmission with a 6 speed... basically, it's just clever (yet funky) programming on a 4L80e that kind of gives you more gears through a different lock-up pattern. They've been putting 6 speed autos in hotrods for a couple years now....

With that said, it's still easily 5 grand (or more) to put an 6LxxE transmission in anything right now - will you really spend 5k more on fuel? With that said, if you want paddle shifters - the 6 speed is the way to go. The easiest/cheapest way to get over drive is a NV4500 or (if lucky) and NV5600 manual transmission (6 speed).

But consider this - the reason for a billion gears is a narrow torque/hp band. Whether a motor is running a 4500 rpm or 2500 rpm doesn't really make any difference to economy.... eye opener for me on this was this. I blew my transmission in grapevine california headed north. I was getting 13 mpg towing a trailer in my 93 Chevy truck. I lost direct drive and overdrive. I drove from grapevine to roseburg oregon ..... and got exactly the same mpg as I got with over drive going south... spend your money on EFI. If you really need more gears, look into a NP241/NP205 splitter hybrid case from NWFab - he's over on Bainbridge and builds a quality product.

In a 'burb, you'd run 2.73 gears, then with the doubler you will get to a 9:1 gear reduction in 3 steps....
just a different way of peeling the onion

 

[superbuickguy]

The cost of the doubler is about 1,000 if you get all primo parts - you can save a lot and get it for 750ish with some shopping... best of all, it's all gears no breakage.

 

[Larry]

there are controllers for the 6L80e (e.g. http://zerogravityperformance.com/6l80e-stage-1/) whatever you do, don't mistake the TCM transmission with a 6 speed... basically, it's just clever (yet funky) programming on a 4L80e that kind of gives you more gears through a different lock-up pattern. They've been putting 6 speed autos in hotrods for a couple years now....

Nice! About time the aftermarket caught up with the 6L however the cost of admission is crazy. I hadn't ran across those guys yet. I tell you this, several of our customers are running 6L90s in delivery vans and they are holding up much better than the 4L80Es. It was not uncommon to see major catastrophic failures on in warranty 4L80E whereas we really don't see any failures on the 6L90 other than control valve failures. Even at that control valve failures are pretty rare, its just the only thing on the 6L's that seem to cause warranty expense.

 

[superbuickguy]

Nice! About time the aftermarket caught up with the 6L however the cost of admission is crazy. I hadn't ran across those guys yet. I tell you this, several of our customers are running 6L90s in delivery vans and they are holding up much better than the 4L80Es. It was not uncommon to see major catastrophic failures on in warranty 4L80E whereas we really don't see any failures on the 6L90 other than control valve failures. Even at that control valve failures are pretty rare, its just the only thing on the 6L's that seem to cause warranty expense.

were it me, I'd go option 2 (NP241/205) with highway gears and a turbo 400....it would be nearly bulletproof. If you really need more strength (heaven help you keep it between the ditches), you can build what I did for my Buick (900 hp bbb turbo), and use the straight cut gears out of a 475 in a 400.

 

[barefoot boy]

I just put a passenger side drop 205 from a TH400 behind a 4L80e. I had to add a .600" machined spacer from NW Fab between the rear face of the 4L80e and the factory 205 adapter. This .600" is necessary for the factory 205 adapter feet to clear the rear pan rail on the 4L80e.

 

[Woofwagon]

This is great info guys. I'm laying out a 3 year plan of what I want to modify or improve on the Suburbillac in terms of durability and maybe get some increased range.

 

[superbuickguy]

If you need a NP 205... why do I suddenly feel like your illicit autopart supplier?

 

[Woofwagon]

Hey it's car dudes helping out other car dudes. I still need to climb under the 'burb and see if it is indeed a NP205. What I'd like to get is the overdrive supplied by a 4L80E. I had thought about a toughend up 700R4, but have doubts as to its durability under the kind of torque the Caddy would be producing.