Diesel with a manual transmission

[fixbroke]

I've had the (dis)pleasure of driving a friend's F150 recently, and it reminded me that I really don't want an automatic transmission. However, my CTS-V has spoiled me for torque and I'm not sure if the Pentastar in the JT is going to cut it.

How feasible do you think it would be to swap a manual transmission onto the diesel engine? Assuming that the gas and diesel 8-speed transmissions are similar if not identical, it seems that a 6-speed should bolt up. Pedals and a clutch master should also be bolt-in additions. The gear ratios may be poorly suited to the low-revving diesel, but that could be fixed with the addition of some 37" tires. The ECU and TCU would probably not be happy, however.

It's likely to be too much difficulty and expense to go that route, but I can't help but imagine how perfect that combination would be. Cheaper than a supercharger, and with much better fuel economy.

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[Ian cj10]

yea i wouldnt want another auto the colorado ive got is auto 6spd its got too many gears its always changing gives me the shits now theyre going for 8spds itll be worse the only autos ive got that i like are 727s & they only have 3spds so they only change when needed they will stay in top on a slight incline

 

[Oilburner]

The problem is that there is not a manual transmission that is designed to handle the torque the 3.0 puts out, unless you were to swap in a HD truck transmission like an NV4500. No swap kits that I know of.
I prefer to row the gears too, but will have to settle for the diesel
auto. I had a 3.6 + the 6 speed and it left me wanting-

 

[Ian cj10]

yeah i know i get it im just having a bitch

 

[Karnivoolfan]

I miss the torque too of a diesel. Throw a supercharger on the 3.6?

 

[JTRUBI]

Why not buy a manual pentastar and do a Hemi or LS swap ?

 

[fixbroke]

Why not buy a manual pentastar and do a Hemi or LS swap ?

In a word: cost. The diesel option is likely to be $3-4k, and if you could sell the new 8-speed then you could probably come close to breaking even on the trans conversion. A well-sorted 5.7 swap is going to be $10-20k, plus the additional lifetime fuel costs of a thirsty gas V8.

 

[Oilburner]

Why not buy a manual pentastar and do a Hemi or LS swap ?

Because the Jeep 6-speed is only rated for 272 lb ft or torque max input. You could frag it pretty easy by just adding a supercharger to the 3.6, much less an LS.

 

[fixbroke]

Because the Jeep 6-speed is only rated for 272 lb ft or torque max input. You could frag it pretty easy by just adding a supercharger to the 3.6, much less an LS.

That was the torque rating on the JK's NSG370. The JL and JT use the new Aisin D478, for which there doesn't seem to be a known torque rating. We can assume it's at least equal to the old 272 lb ft spec, but hopefully much more.

 

[Oilburner]

That was the torque rating on the JK's NSG370. The JL and JT use the new Aisin D478, for which there doesn't seem to be a known torque rating. We can assume it's at least equal to the old 272 lb ft spec, but hopefully much more.

Ah - didn't know that. Must have been a post-Daimler thing. They needed a 6-speed but didn't want the German one so they got an Aisin equivalent?
I see that you can't get the JL with the 2.0L (295 lb-ft) with a 6-speed, I wonder if it's a logistical thing or because the transmission can't handle the power-

 

[homerun]

I too would love to know the torque rating of the D478. It seems that info is no where to be found. I have even checked Aisin website. https://www.aisin-aw.co.jp/en/products/drivetrain/index.html or here http://www.aisinworld.com/products/drivetrain/

 

[WXman]

Seems like I read 350 lbs/ft torque input somewhere but I can't find where I saw that now. In any case, there's a few good reasons FCA isn't pairing the EcoDiesel with the D478 and torque capacity is one of them.

As far as ratios go, assuming it would work I think the D478 ratios would be well suited to the EcoDiesel. They are taller than the outgoing manual transmission, which would mate up well with the diesel torque and make for great driveability.

 

[bruno747]

back when I researched putting an ecodiesel in my dakota, it seemed feasible from what I could find.

You would have to russel up one of the Getrag 238 6 speeds the rams and dakotas used around 2005-2008. These are the manuals they use behind the 6.4 hemi jk swaps without issues. Probably would also be looking at crossmember work and potentially driveshaft work depending on how all the distances work out.

The bigger issue is electrical. The diesel is so tied in and dispersed that it might be near impossible to get it working properly on your own. Its not like the old Magnum v8s where you would just splice and move the neutral safety switch to the clutch pedal switch and voila good to go. There also isn't a manual ready ecu that you can just swap and be good to go since fiat hasnt offered a manual behind this engine in any format or model.

That said, its possible someone like green diesel engineering could work something up for you to get it running and ignore transmission input.

Personally Id love to be able to order a Gladiator with out engine or transmission for a significant discount so I can just put a hemi 6 speed in it to start with like it should have as a factory option.

 

[fixbroke]

I'm starting to lose my enthusiasm for this idea. Supercharging may be the preferred solution for torque with a manual trans.

1. The Ecodiesel is a $4500 option for the Ram 1500 - more expensive than I expected. (For comparison, superchargers kits are $5-6k)
2. There have been a lot of expensive issues and premature failures with Ram 1500 Ecodiesels.
3. The transmission and the rest of the vehicle computers are far more interconnected than I had originally considered (as noted by bruno747). I sent an email off to Green Diesel Engineering to see if they could make it all work together, but I'm not expecting an optimistic answer.
4. As I may have to register the truck in California, the smog referees are unlikely to allow a more-polluting transmission substitution.

 

[Karnaj]

I'm starting to lose my enthusiasm for this idea. Supercharging may be the preferred solution for torque with a manual trans.

1. The Ecodiesel is a $4500 option for the Ram 1500 - more expensive than I expected. (For comparison, superchargers kits are $5-6k)
2. There have been a lot of expensive issues and premature failures with Ram 1500 Ecodiesels.
3. The transmission and the rest of the vehicle computers are far more interconnected than I had originally considered (as noted by bruno747). I sent an email off to Green Diesel Engineering to see if they could make it all work together, but I'm not expecting an optimistic answer.
4. As I may have to register the truck in California, the smog referees are unlikely to allow a more-polluting transmission substitution.

Keep in mind, to your point 2, those were the first generation ecodeisel engines. The ones being placed in the JL/JT are going to be their second generation ecodeisel. Optimistically those problems should be mitigated.

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