GM 4L80e info page.

Having finally obtained a 4L80e to examine, Ive looked at the possibility of using that instead of a 700R4. As of today, my current 700r4 rebuild isn't giving me any problems - therefore I have no immediate plans to fit this box. This page is just to collect the information and document the possibilities.

4L80e background.

Its an Electronically controlled 4 speed automatic box with lockup torque convertor. . Its very beefy, but very heavy.It is loosely based on the very strong and well proven Turbo TH400 transmission. The 4L80e is a very robust unit can withstand up to 440 ft./lbs of torque in stock configuration, and much more when modified. This guy is putting over 1000 BHP to the wheels using one.. It was fitted to various american cars and trucks, including the Hummer H1. It can also be found behind the following non GM cars:
Aston Martin V8 Volante 1995
Aston Martin DB7 (possibly?)
XJR X300 1995-1997 AJ16 4.0 SC
XJ12 X300 1995-1996 V12 6.0
XJS 1994-1995 V12 6.0 4-Speed GM 4L80-E

Most interestingly its found behind the 2.5 ton, twin-turbo 6.75L V-8 Bentley Arnage R, producing 400 hp and 616ft-lb of torque. Dimensions and More identification information can be found here

Controlling the 4L80e

Updated 10/3/08
Because the 4L80e is an electronic transmission, you need to either convert it to full manual or get a control module. Transgo list a Full manual conversion, which totally eliminates the electronics - the line pressure solenoid is replaced with a vacuum modulator.
PATC (Amongst others) offer a full manual 4l80e, no electronics required.

Aftermarket Electronic Transmission Controllers:
Powertrain Control Solutions
TCI Trans computer (Although i note their latest unit is actually a PCS device!)
Compushift
Baumann Electronic Controls
You can also use the GM controler that was used in diesel trucks

DIY/Experimental options:
The GPIO (General Purpose IO board) is currently in beta and will be available soon - it will work standalone without a megasquirt..
Also,
Megasquirt guru James Murray has written code that turns a Microsquirt into a transmission controller, Its in alpha awaiting physical testing on either his or my 4l80e depending on who gets their box fitted first.

The Jaguar OEM 4L80e

Because I live in the UK, getting hold of a genuine 4L80e *cheaply* is difficult. However Ive obtained a Jag 4l80e gearbox, which has a different casting for the Jag bellhousing and the oil pan is different.
Markings on the box: Z JP hydra-matic
The GM box is rounded of at the back, whereas the Jag version is square.
Jaguar OEM 4l80e GM 4L80e

View of the valve body, The internals are the same. Although the right hand one is the PATC full manual conversion, hence no electronics:(Feel free to contact me a similar photo with the electronics in it!)
Jaguar Internals GM Internals

Externally, the electronics connector is on the other side in it's own custom hump
Jaguar 4l80e gearbox GM 4l80e gearbox

The electronics connector is more like a Mil-spec connector. Bellhousing is totally different.
Jaguar front pump GM Connector

Suitability for conversion onto Range Rover LT230 transfer box

These photos show the Jag 4L80e lined up with a LT230. First problem is that front propshaft hits the casing, whereas on a std 4l80e this part would be rounded off, giving better clearance.
One choice is to move the LT230 further back, but Ive already moved it back 3" when I fitted the 700r4, this would require moving it back a further 3". The other choice is to cut the corner of the gearbox of. Sounds dramatic, but if you study the photos above I think its easily done. This means I might be able to get the overall transmission length to be the same as the 700R4 conversion due to the extra clearance from the missing corner.


Here's the potential space saving:

Marks adapters

Finally i have photo's of the Marks Adapters conversion for the 4l80e, courtesy of James Pugh who's fitting one to a 4x4 buggy with an LS1.

Having seen that there is clearance, I'm now working on my own adapter: Next Page - My 4l80e conversion

Comments, questions or got answers? Please use the Mez Forums to get in contact or chat about this page.


Search my pages:
Web mez.co.uk