TCM Tune

timothyd · **Joined:** Wed Feb 20, 2019 2:58 am **Posts:** 90

With Green Diesel down for now, does anyone know of anyone else that tunes the TCM for these?

TKB4 · **Posted:** Fri Feb 21, 2020 8:21 pm

I dont but since the TCM doesn't require the vehicles VIN I would think someone could do it even if outside US or maybe one already tuned like you want will come up for sale . I have the economy TCM tune on one and love it. If anyone tunes the Hemi TCM they can probably tune one for the CRD. If someone needed a GDE one for a few days to analyze it somehow I could probably arrange that with a fairly large deposit.

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

FOLLOWING...

I think a TCM tune is necessary to get maximum efficiency out of these vehicles, but perhaps I am wrong.

It just seems to me that an automatic transmission mated to a diesel engine should shift at different RPM and lock up at different RPM to that same automatic transmission mated to a gasoline engine. Is it not the case that a TCM tune can change these parameters to squeeze maximum efficiency out of the driveline?

Input from other LOST members very welcome here. WWDiesel? gmctd?

Rrusse11 · **Posted:** Sat Feb 22, 2020 9:11 am

Newbie here, but I would assume any comprehensive tune would include re-programming the transmission. In my very limited experience with the 5 spd auto, it shifts too soon for the torque band of the diesel, overpowering the TC. Rightly or wrongly, I'm using the OD button to help control
the tranny, letting it rev a bit higher before shifting in the high gear(s). Keeping it in 2nd around town gives some engine braking and more control over momentum rather than constantly having to ride the brakes. Dyed in the wool manual tranny fan here, I feel the auto is the one big drawback to the CRD.

My66dodge · **Posted:** Sat Feb 22, 2020 10:52 am

As a diesel mechanic who has built MANY hot rods I can tell you that an auto is far better for a turbo diesel than a manual. With an auto when you are driving hard the turbo keeps spoiled the whole time unlike the manual, also though it doesn’t effect our little engines using a clutch with a high HP turbo diesel is a two footed affair and no fun to drive. A manual is fun for driving but has disadvantages for a hoped up truck

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WWDiesel · **Posted:** Sat Feb 22, 2020 2:32 pm

Rrusse11 wrote:

Newbie here, but I would assume any comprehensive tune would include re-programming the transmission. In my very limited experience with the 5 spd auto, it shifts too soon for the torque band of the diesel, overpowering the TC. Rightly or wrongly, I'm using the OD button to help control
the tranny, letting it rev a bit higher before shifting in the high gear(s). Keeping it in 2nd around town gives some engine braking and more control over momentum rather than constantly having to ride the brakes. Dyed in the wool manual tranny fan here, I feel the auto is the one big drawback to the CRD.

Keep in mind the ECM & TCM are separate control devices. Reflashing for a better engine tune does not affect the software or files on the TCM.
I respectfully disagree with you on shift points. If you retune your diesel for more HP & higher torque and have a very good torque converter like the SunCoast along with the new updated front pump assembly and TransGo Kit installed, it will handle the lower shift points & TC lockups flawlessly. This engine makes lots of power at lower RPMs if tuned properly.

Actually, the transmission retune that GDE used to provide, before they got busted by the EPA, lowers both shift and TC lockup points in 4 & 5 gears, but it does require a very good TC to handle it and not slip or shudder in lockup accelerating uphill. I have a Stage IV Hot Tune and one of GDE's eco transmission tuned TCM's and they function together seamlessly without any TC issues.
I rarely every run this engine above 2500 RPMs as it just isn't necessary with all the power it makes around 1800-2000 RPMs.

TKB4 · **Posted:** Sat Feb 22, 2020 6:45 pm

I agree I have the eco GDE trans tune and hot tune ecm tune and the Hemi TC and can still accelerate in lockup pulling 2-3000lbs up the mild hills we have in 4th and 5th. In fact I mainly got it so it would shift to 5th gear lockup at lower speed and hold it down to speeds I usually go and I rarely drive at more than 1900 rpm except where shift points dictate I more often drive around 1750 rpm which is about 63 with my current tires.

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

Rrusse11 wrote:

Newbie here, but I would assume any comprehensive tune would include re-programming the transmission. In my very limited experience with the 5 spd auto, it shifts too soon for the torque band of the diesel, overpowering the TC. Rightly or wrongly, I'm using the OD button to help control
the tranny, letting it rev a bit higher before shifting in the high gear(s). Keeping it in 2nd around town gives some engine braking and more control over momentum rather than constantly having to ride the brakes. Dyed in the wool manual tranny fan here, I feel the auto is the one big drawback to the CRD.

Do you have a the F-37 recall done on your Jeep?

Chrysler had recalledand the engine detune (from 295lb/ft to 260 if I my memory is good.) and the shift points raised to accommodate a weak torque converter.

I think the main reason why the GDE trans tune is to lower back those shift points when paired to one of their engine tunes !

From my experience I don't mind the higher shift points too much since I installed larger tires. (245/75R16)
I have the original TC with a Ecotune and I manage the shudder not too bad !

I also have a transmission from a Dodge 1500 5.7l with the TC that I'm looking to install at some point but I'm not set on the work I will do on it before I put it in !!!

Rrusse11 · **Posted:** Sat Feb 22, 2020 9:38 pm

"I think the main reason why the GDE trans tune is to lower back those shift points when paired to one of their engine tunes !"

PZKW108 & WW,
Like I said, both computers should be tuned together. I'm hobbled by the F37 "fix", and an elderly TC, albeit remanned. I'm finding it's the low 2k where the motor seems to be running the best at the moment.

Still learning here how the vehicle and engine work together. My modded Golf TDI is not the same animal.
Lol, in spite of the naysayers, I still want a manual! {:o) I'll get used to the auto, but I'll never love them.

Brakes all round now, oil change, and the parking brake works, albeit I'm going to have to tweak the cable. Fix the transfer
case switch, and then the tune, both Ecu and Tcm. There's an upgraded TC and associated improvements in the
future, just not right now. I'll get a mild tune and the EGR block off plate in, and live with the tranny the way it is. Don't need a hot tune, the Jeep's the truck, Golf is the GT machine.

Thanks gents! Appreciate the knowledge and experience, the Libby is growing on me. I think I'm going to keep it.

WWDiesel · **Posted:** Sat Feb 22, 2020 11:32 pm

The Hot tune is all about power and torque, has nothing to do with being a GT! :lol:

Rrusse11 · **Posted:** Sun Feb 23, 2020 10:02 am

WWDiesel wrote:

The Hot tune is all about power and torque, has nothing to do with being a GT! :lol:

After a major transmission overhaul, I'll be tempted I'm sure. At the moment with the F37 "fix", I'll be happy to get another 20hp or so and hopefully a bit better economy. I also don't want to stress out my high mileage engine. Been down the road of the slippery slope of mods, more is always tempting. Yeti, I believe has a mild tune, that should be just fine for my purposes at the moment.

Ordered TBD's thermostat, the HDS, that should help keep the engine going, unfortunately it'll be a while before he can supply one. From what I've been reading, rockers and lifters may need doing, although the original owner always used 5w-40 which may have helped there. Time will tell. Got the block heater plugged in every night, that certainly helps with warm up time.

mass-hole · **Posted:** Sun Feb 23, 2020 10:46 am

I searched briefly and it seems that VERY few people tune the 545RFE TCM for any platform, nevermind the CRD. I wouldn’t get your hopes up.

I just sold my GDE eco tuned tcm, so keep an eye out and you may find one.

TCM Tune

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