Manual to Auto trans conversion

[01_Cummins_4x4]

I was curious if anyone on here has done the reverse and went from a manual to an auto trans?

 

In my 99 Cummins 4x4 that I used to have a few years ago, I swapped out the auto trans and installed a rebuilt NV4500 that my buddy and I overhauled and installed a brand new South Bend single disk clutch. I kept my ECM and PCM and installed a manual trans stock tune file from Mads with a Smarty and it ran great after that. At the time my left knee had stage 4 arthritis in it and it wasn't liking a stiff clutch at all, so I found a friend that had a verified rebuilt auto trans with paperwork from Baker City, and we spent a long day swapping transmissions and input shafts in the t-cases, and all the other related hardware.

 

I have this 01 Cummins HO factory 6 speed truck now that has an aftermarket clutch and hydraulics (shifts great) in it, and more often lately I'm thinking of finding someone with a verified built auto trans to swap with. My truck has an Industrial Injection VP44 pump, 100 HP SAC DAP injectors, S & B air cleaner setup, Quadzilla tuner, AFE intake horn, 4" exhaust system, and an Airdog 150 lift pump, so I don't want to trade the truck for an auto truck unless the auto trans can be verified fully rebuilt and has the same performance mods that I have in my truck.

 

My left knee has been fully replaced in Oct 2018, but I still cannot bend it past 95* since I have scar tissue that's built up in my quadricep muscle right above the knee joint. My ortho doc said that he could give me a chemical cocktail to knock me out and force it manually to bend further at the risk of breaking something else in the process. 

 

I know I'd have to swap trans, flywheel, clutch, hydraulics, t-case, driveshafts, pedals, shifters and linkages, steering columns, TV cable for APPS, and probably PCM harnesses. I'm assuming that I'd have to swap the PCM for the auto trans to shift correctly? I guess if both trucks were 2001 with the same ABS setup, could a person just swap the ECM and PCM modules, or since mine is a HO and theirs would be a SO truck, would that not work? Just trying to get some ideas...

 

 

Edited January 21, 2022 by 01_Cummins_4x4

[Silverwolf2691]

Not versed in transmission swaps but you dont necessarily need the column. You could get like a ratchet shifter but you would need to make a mount for it.. Unless you want/need to keep it stock

 

PCM and ECM are probably both going to need flashed at a minimum, and need the harness to go to the trans for sure.

Edited January 18, 2022 by Silverwolf2691

[01_Cummins_4x4]

I don't want the ratchet shifter as it would cost a lot more money than just swapping out the steering column and shifter linkages, unless someone was selling a used ratchet shifter for a great deal.

 

 

[Great work!]

Most parts shared with gas trucks are easy to get at a junk yard or online. The diesel stuff like flywheel and heat exchanger are much harder to get and cost more.

[Sycostang67]

How many miles you got on that 6 speed?  I have a built auto with 40k miles.

[01_Cummins_4x4]

My truck has 197k on it. I bought in Dec 2020 and it already had the aftermarket clutch and hydraulics in it. The only thing I've added is a short throw shifter tower kit in it.

[Sycostang67]

I think the only difference with the SO and HO motors was the VP44, I think the HO version has more timing.

 

If you are interested in swapping, I may be interested as well.  I really wanted a manual in my truck but they were non existent when I was shopping.  I had my Transmission built here in Idaho at Ultimate Transmission.  They hooked me up with their towing package.  Billet flex plate, billet low stall single disc converter built in house by their guys, billet input shaft and all the other usual billet goodies that come with it, extra upgraded clutches and all that.  They told me it was good for 650hp.  I had them tear the T-case apart and reseal it as well.  I took it in at 25k miles for the first service and they said everything looked good, I've got just over 40k miles on it now,   I'm just running the OEM trans cooler and a B&M finned aluminum pan and the trans has never gotten past 160*.   The only thing about it that bugs me a bit is it really kicks when it shifts into 4th gear, it only does it if you are empty and putting along.  Toss a load behind it or give it some beans and it's smooth.  I asked the shop about it and they said it was normal for my build.  They said there was some adjustment they could make to smooth it out a little but it would still be there.  

 

If it sounds like something you might be interested in, let me know, if not it's all good.  

[Silverwolf2691]

43 minutes ago, Sycostang67 said:

the only difference with the SO and HO motors was the VP44, I think the HO version has more timing.

 

More than just vp44, there are engine hard part differences. Also 6 speeds are HO only, except for a few early 2000 or 2001 trucks (a rarity to find)

[01_Cummins_4x4]

If I remember correctly the HO has higher compression in the engine vs the SO engine.

 

Sycostang67, I'm definitely interested!

Edited January 21, 2022 by 01_Cummins_4x4

[Mopar1973Man]

I've done 47RE to NV4500 conversion. 

 

Make sure to have both ECM and PCM reflashed. 

 

Now for Manual to Auto you will need to swap the electrical harness being the auto will require wiring for the auto. Converting to manual you can leave the auto wiring in but it will be short features like reverse lights being the auto plug won't work.

[01_Cummins_4x4]

Can't we just swap the PCM harness for the transmissions? 

I know I can flash the ECM with a Smarty and load the stock tune for the manual or auto trans, that's what I did on the 99 Cummins 4x4 I had a few years ago.

 

If both trucks are the same year and have the same ABS setup, could we swap ECM and PCM modules in pairs between the trucks?

When I did the 47RE to NV4500 on that 99 4WD Cummins I did, I just flashed the ECM with the manual trans stock tune which gave it the anti-stall feature.

 

I'm trying to remember does the PCM control how and when the auto trans shifts via the electronics in trans?

 

Also, isn't there a trans relay in the PDC that I would need for the auto trans?

 

6 hours ago, Sycostang67 said:

I think the only difference with the SO and HO motors was the VP44, I think the HO version has more timing.

 

If you are interested in swapping, I may be interested as well.  I really wanted a manual in my truck but they were non existent when I was shopping.  I had my Transmission built here in Idaho at Ultimate Transmission.  They hooked me up with their towing package.  Billet flex plate, billet low stall single disc converter built in house by their guys, billet input shaft and all the other usual billet goodies that come with it, extra upgraded clutches and all that.  They told me it was good for 650hp.  I had them tear the T-case apart and reseal it as well.  I took it in at 25k miles for the first service and they said everything looked good, I've got just over 40k miles on it now,   I'm just running the OEM trans cooler and a B&M finned aluminum pan and the trans has never gotten past 160*.   The only thing about it that bugs me a bit is it really kicks when it shifts into 4th gear, it only does it if you are empty and putting along.  Toss a load behind it or give it some beans and it's smooth.  I asked the shop about it and they said it was normal for my build.  They said there was some adjustment they could make to smooth it out a little but it would still be there.  

 

If it sounds like something you might be interested in, let me know, if not it's all good.  

That's funny as when I was shopping for another Dodge Cummins 4x4, I couldn't find anything that had a verified built auto trans and I wasn't going to take a chance on an auto trans truck off of a car lot, that's why I grabbed this 6 speed truck in Dec 2020.

Edited January 21, 2022 by 01_Cummins_4x4

[Mopar1973Man]

12 hours ago, 01_Cummins_4x4 said:

Can't we just swap the PCM harness for the transmissions?

Whole engine harness needs to be swapped.

 

12 hours ago, 01_Cummins_4x4 said:

I know I can flash the ECM with a Smarty and load the stock tune for the manual or auto trans, that's what I did on the 99 Cummins 4x4 I had a few years ago.

 

that takes care of the ECM but you really should do the PCM as team which the Smarty can't do.

 

12 hours ago, 01_Cummins_4x4 said:

I'm trying to remember does the PCM control how and when the auto trans shifts via the electronics in trans?

1st, 2nd, and 3rd are all hydraulic shifts. Then 4th gear is electronic. The torque converter lock up is electronic. There is governor pressure sensor and the governor solenoid which is electronic controlled. Then the trans temp sensor for temperature which is relayed to the PCM as well. 

 

[01_Cummins_4x4]

That's what I meant about the PCM harness, that it's the whole engine harness which should be a simple swap between both trucks.

[Sycostang67]

Is there anything specific about the ECM/PCM being one truck is an HO?  The other thing I wonder about is the gauge cluster.  I'd rather not swap that unless there is someway to keep my odometer current.  

[01_Cummins_4x4]

13 minutes ago, Sycostang67 said:

Is there anything specific about the ECM/PCM being one truck is an HO?  The other thing I wonder about is the gauge cluster.  I'd rather not swap that unless there is someway to keep my odometer current.  

We just pull the clusters out and swap the auto trans gear indicator for my manual trans plate. We don't have to swap clusters at all.