I have had a lot of questions about other transmissions options. I figured it would be good to start a topic on it. Here are some thoughts / anticipated issues. It generally turns out a lot more expensive and/or work intensive to change up the transmission along with the engine. Moving the transfer case back can get complicated between rewelding mounts to the frame and driveshaft lengths/angles. The largest variable for the cost is how much you can get your engine/transmission/ECM for.

General Fitment

· 4L60 is impractical because of interference issues with the transfer case.
· 4L80 is an option, but will require the transfer case to move back about 6in, new transfercase mounts and new driveshafts.
· 6L80 is best alternate option to 4HP24, but is much more expensive and requires a Gen 4 engine / Gen 4 ECM for operation unless using some really expensive transmission controllers, but the transfer case would not have to move.
· There’s a couple options for manuals, but it seems most people steer away from the R380.

A 4L80e is long and requires the transfer case to move back and the driveshaft lengths to change (which changes several other things as well). A 4L60e is too wide and conflicts with the transfer case, which means to fit it you would have to use a lengthy adapter. This would be a lot of extra work, because you would have to move the transfer case back quite far. There are limitations on how far the parking brake drum can move before hitting the body floor or requiring a new cable. If this occurs, a body lift may be a solution. Similarly, the engine can only move forward a few inches before you start having clearance issues.

Electrical

We have not done this, so this is from a purely theoretical standpoint, for most of it. Some tips more or less:
· General operation with 4L60/4L80 would be the same as with the 4HP24. Current ACE electrical setup would work to get basic functions back, but the wiring would be more intensive to get the gear indication, transmission modes, and reverse lights working. There will also be changes to the cruise control system.
· The M and S lights will flash along with the nonfunctional gear indicator without the 4HP24, but there are ways around this with more electrical work.
· VSS issues with the 4x4 version of the 4L60 (maybe 4L80 also?) would have to be solved for the LS Gen 3 ECM to work properly since there is no speed sensor in the Land Rover transfer case.
· 6L80 has a lot more things to deal with the E38 ECM over CAN. Making the gear indication work on the dash would be more complex. Electronic throttle pedal would have to be mounted and used, which would complicate other functions.
· Modifications to the shifter will be required for operation with any different automatic. Obvious modifications with the manual.

 

Will the 6l80 fit without hitting the transmission tunnel

 

I have not fiddled with the 6L80, so I am not sure. I think the bigger issues with the 6L80 will be the electrical, given the CAN bus controls for the shifter, gear indication, cruise control, reverse lights, etc.

 

What inputs does the 4hp24 or 22 need to shift. Crankshaft sensor for rpm, coolant temp for different shift map. What else? I know ACE built a converter box I am assuming most of this was to get the factory gauges to work.

 

Oh man, I had completely left the park brake out of consideration with my swap. It hadn't even crossed my mind yet since I'm swapping transfer cases as well. That is going to be an interesting issue to solve.

 

What do you make of this gadget?
GM 6L45E 6L50E 6L80E 6L90E TCM2650 transmission controller harness

I'd like the 6l80 for a future upgrade.. Sounded impossible without a gen4 engine until I found this.. I just wonder how difficult it would be to incorporate into ACE's wiring...

 

Can't speak to outfitting into ACE's wiring but a friend did a LQ4 and 6L90 into his classic and there was a bit of a learning curve getting the trans shift points set up but once he got it figured out it's fantastic. He tows a small camper and at elevation and through the mountains here he loves having the 6 speed.

 

I’ve seen a few posts on nv4500 swaps with LS engines on defenders
Is this a viable option on a 2004 discovery 2?
I have a lead on a decently priced gm nv4500