Thread: Td6 5L40E Options

As much as we all love our TD6's it looks like we will have to put up with the weaknesses of the 5L40E. And more importantly budget for its failures. There are some means to stenghten parts of the 5L40E but not all. Pity about other options discussed on here but due to the electronic complexities looks like thats what were stuck with.

As we all know our TD6's are able to put out for more power than the 5L40E can handle. Which is a real shame realy.

There was this this a 5L40E with 5L50E bits stuffed in it behind an LS7
2009 Pontiac Solstice - LS7 - 5-spd Automatic

Gary

Gary
I've e-mailed Wade previously and his reply is below. This is now shaping up as option if we can sort out the output shaft dilemma ! As you have seen in the previous post the Transfer Case could also become an issue re- input shaft availability.


From: Wade Linger [mailto:wade@linger.com]
Sent: Monday, 28 May 2012 12:06 AM
To: 'Laurie'
Subject: RE: 5L50E

As you probably know by now, there is little support out there for the 5L40 – 5L50 transmissions. The way we did it was to buy a 5L50 out of a Cadillac XLR. It had all of the beefy internals. It also had a half-bell housing that made it possible for me to design an adapter to mate it with the LS7. It was a bit tricky. Ultimately I learned that the better path is to get a 5L50E out of a 2006 Cadillac STS-V. It is designed to work behind a V8 on a rear wheel drive car. In my case, the STS-V transmission combined with the XLR half-bell and my adapter would have done the trick without having to get into the internals of the transmission.


I suppose the next question to ask is " did the 5L50E have the same valve body, pump and torque converter issues ?

Laurie

I have just recieved the pricing for the H/D output shaft from Jpat !

http://www.jpat.co.uk/5L40E%20Shafts.pdf

Shaft is $367.41 (£225.00)

Delivery by TNT is $114.71 (£70.25)

The cost of the output shaft is roughly twice that off US sourced products for Ford & GM automatics, but this would be a limited production run item. I'm sure we could get a better freight price though.

Laurie

Originally Posted by harlie

However, with a bit of work it would be possible to get a manual box going, the auto trans ECU would need to stay and be fed some dummy input values (create a little black box, stub if you like.)

Hi Harlie, what info do you think the manual needs to send the engine ECU? I have been looking at fitting the 5 speed manual from the X5 as a viable option, but I have never been sure what the car needs electronically.

Cheers - Gav

Gav,

A Manual will not need to send anything for it to work. Unlike an Auto, a Manual does not require the engine to do anything for it; the driver is now responsible for making gear selection decisions, cutting the power for gear changes and smoothing out operation of the transmission and clutch.

However, for the rest of the car to work (as you’ve confirmed strange things happen when comms to the trans are lost) there are a couple of options I can immediately think of.

• Get the engine ECU from the donor BMW manual car (make sure the donor car has less km than your car – odo is stored in the ECU). I’ve not looked into this exact scenario, but if the donor car is pre 2003 there’s a good shot, but may need some if not all of the engine sensors as well. You may however find issues with the looms, and will need soft programming of the ECU, VIN number & odo (dealer if they will do it) will be needed for the car to accept it. One issue will be the inability of diagnostic equipment to access the BMW engine ECU because it has a different part number range (they search the bus for a certain part number (DDE4-EMS), an indi BMW workshop may be needed. This avenue would need some more research and could get messy.

• Convince the car that the gm box is still there and all happy. This would involve feeding some analogue values into the Transmission wiring loom so the existing Trans ECU can feed data to the CAN bus. I’ve listed above what the Trans ECU sends out, but what would need to be worked out is which essentials the car needs, and that may be a bit of trail & error. At first look the Trans ECU will need to transmit at least ‘Selector lever position’ & maybe ‘Current gear’. The 1st is easy, the 2nd would need a bit of creativity if it is required.

The car, as an auto definitely needs the ‘Selector Lever Position’ value, it would need to emulate P to start, and remove the key and I suspect emulate D to satisfy the BCU (traction/Stability/ABS ect). Since the engine ECU listens for the ‘current gear’ value I suspect it is doing something with it. A bit of creativity could solve this one.

A Clutch Swith would be needed for legalities (Cruise cutout) and I'm sure with a bit or testing it could also feed the loom and return a value to the CAN to drop cruise out.

Reverse light switch would need to feed into the old trans loom as well so that is fed to CAN

Any reason for looking at the 5 speed? 2004 on they had 6.

Originally Posted by Laurie

I have just recieved the pricing for the H/D output shaft from Jpat !

http://www.jpat.co.uk/5L40E%20Shafts.pdf

Shaft is $367.41 (£225.00)

Delivery by TNT is $114.71 (£70.25)

Laurie

Were you thinking of a group buy Laurie. If so I'm in. Just to have one sitting in the shed for when

Gary

Originally Posted by harlie

Any reason for looking at the 5 speed? 2004 on they had 6.

Um - not really... My thinking was just going along with what was used in the X5 during the same year. If the bolt pattern is the same on the 6 speed, and the back end of the box would allow the TC to bolt up, then it seems like a good idea - back to the BMW forums to get some more answers...

Cheers - Gav

Gary
I didn't consider a group buy, as I'm in no hurry at the moment.
I was considering getting the main shaft Cyrotemped during the rebuild as a H/D shaft is unavailable, so time isn't a big factor.
I even considered a D3 HSE TdV6 at one stage,as this gearbox has so little support anywhere !

Laurie