2006 Savana van 5 spd conversion

[cabledawg]

Future project once the Burb is truggied out. It's a 2006 with the 6.0L and 4L80E trans. Trans has been replaced once and repaired two other times. I hate slushbox trannies. Anyways, I'd like to look into swapping the auto for a 5/6 spd manual. I know fitting a clutch is going to be a PITA but I'll manage. It's the electronics I'm not sure about. I assume I'm looking at changing out the CPU with the tranny but is the wiring the same between the two? All I can find for the Savana van shows the AT only and I havent been able to find an in depth diagram for the trucks (that would most likely be a donor). If someone has a detailed diagram I could look at, that'd be a good start. Likewise if anyone can think of anything I'm missing, please speak up. TIA

 

[blowedupmotor87]

I would think the best route would be to get the trans and computer from a Silverado/Sierra that had the 6.0 and six speed manual. You could also get the hydraulic clutch setup from that donor too. It'll likely be a long search but, they are out there! VERY cool project, never seen a 6 speed van! May want to make sure your transmission choice puts the stick in a good position though, or else you may find yourself having to make a very custom shifter setup!

 

[handloader90]

The transmission portion can be deleted from the computer. Just have to pull the computer and send it off.

I'm currently in the process of putting a SM465 behind a 6.0 (LQ4) that's going into my '79 K5. The guy that flashed my computer removed the automatic transmission stuff from the computer.

Make sure you have a plan for VSS. My buddy did an NV3500 swap behind a 5.3 in his '91 Burb, didn't factor in VSS and his engine will sometimes shut off when he comes to a stop.

 

[campfire]

Any newer 2WD tranny should have VSS covered, no?

 

[handloader90]

Any newer 2WD tranny should have VSS covered, no?

I would assume anything attached to a Gen III engine would have VSS due to it's part in making the system function properly.

From what I've heard/read manual trannies behind Gen III engines are somewhat rare, I believe they put manuals behind the 4.8 (NV3500?) and the 6.0 (NV4500?), I had to use a 4.8/6.0 flywheel to mate my SM465 to my 6.0, so they used something manual behind them. I do not believe a manual was ever used behind a 5.3 from the factory. I've heard that the 6.0 trucks with manuals were only "work trucks".

My buddy has that NV3500 behind a 5.3 and it has help up fine, but I know the NV3500 is only rated for so much horsepower/torque (don't know the numbers) and I don't know if I would put one behind a 6.0... seems like breaking something would always be in the back of my mind.

I know that Dakota Digital has some kind off electical VSS device, I've heard good an bad about it and I'm not sure how it works either.

If the OP has an NV4500 (IDK if they ever made a 2WD version) that seems like a more solid choice than an NV3500. Could always throw a 2WD SM465 in there though, about 20x cheaper than a NV4500 if not almost free lol.

I'm by no means an expert on the matter, just sharing things I've learned.

 

[campfire]

Yes, 2WD NV4500s were made. Same case, with a different bolt-on tail housing.

 

[454Sub]

You can remove all the automatic tranny wiring from any harness, and repin the main computer connectors with the wires for a manual. It i believe is only two wires. One for a clutch switch and one for a shift light. Even if it wasn't offered the two large colored plugs are the same. It can be pinned in at will. Or removed. The computer doesn't matter.

 

[Russell]

There is more to a manual transmission tune than just "switching" the auto trans stuff off. There is a lot of differences in how the idle is handled etc with a manual transmission. This can only be done with an operating system change.

The good news is that 6.0L engines were available with NV4500 5 speed manual transmissions. You can get a proper 6.0L / NV4500 operating system and update it with the engine tuning for your specific year / make / model to have it run like stock. Wiring is pretty straight forward. Remove the neutral safety / backup switch from the trans and wire in a clutch safety switch and reverse light wiring for the manuals trans instead. The gear position indication wiring can all be removed. Finding pedals to fit a van may be difficult, I'm not sure if there was ever a manual transmission van offered. On top of that, the shifter would be positioned well behind the driver's seat in a van as well.

 

[cabledawg]

Clutch will be the biggest challenge. But I can fab stuff enough to build a custom setup, just wont be able to have anyone with big feet drive. Hell I only use the clutch to get started anyways, then float the gears once I'm rolling. Do it on my Burb with a SM465/Ranger OD all the time. As for the shifter, it'll be like driving a cabover. Bend/tweak the shifter forward with shifter movements being somewhat up/down vs forward/back.

Thanks for the info on the computer. Seems way easier than I thought it would be. I am curious and would like to get more info on the 4wd setup vs the 2wd setup. Like what wiring changes are there to address, if any? In '06, I believe you could get a 4wd with a manual shift t-case, correct? If not, I'd be looking at some serious wiring changes as I'm sure the t-case was computer controlled in that situation.

Again thanks for the info so far. My 90 and 88 Burbs were much easier to swap and I dont want to turn the family roadster into an 8k pound lawn ornament.

 

[Russell]

There are no major differences between 2wd and 4wd as far as the computer goes. It has no idea if you are in 2hi or 4hi. That said, there is a 4lo input which is used to change how the PCM shifts the transmission, handles the engine, disables traction control, changes rev limits and also changes the speed output to the speedometer to account for the change in gearing. This is just a ground switch which is open in 2hi / 4hi or neutral and grounded in 4lo.

The transfer case has it's own separate control module independent from the PCM called a TCCM (transfer case control module). The PCM only receives the 4lo signal from the TCCM instead of a switch on the transfer case where a manually shifted case is installed. It doesn't know or case what the TCCM is doing otherwise.