TCM tune or not to TCM tune...that is the question.

Glend · **Posted:** Tue Jul 24, 2012 2:46 am

Klem531 wrote:

Heres just a thought... If I was running the Eco/TCM tunes and wanted to tow, could I just take my CRD out of overdrive until I reached oh say 60 mph then turn OD back on allowing it to shift into 5th. That would get me past that torque hole you mentioned.

That's not the way mine works. It upshifts as low as 1500rpm unless you keep your foot buried in it and resort to OD off. Even with OD off you still locking it in 3rd with the TCM tune and there is a limit on the torque available in lockup, and in lock to lock shifts. The ECO tune has a lockup torque limit of "270 ft*lb in lock-up" and I think this is the fundamental problem I have.

Here's a direct quote from the GDE Forum talking about the TCM tune:

"The tune provides 3rd gear lock-up at 35 mph, 4th gear lock-up at 46mph and 5th gear lock-up at 58mph. Shifting is quicker due to allowing lock-to-lock shifts.

The tune also helps with towing by allowing the customer the option to tow at 55mph in 3rd, 4th, or 5th lock-up. 3rd is available by using the OD off button and the trans will pull in 4th if one accelerates to 55mph and sets the cruise or just maintains speed. 5th is possible by accelerating above 58mph and then slowing down to 55mph. It will hold 5th gear down to 52mph. "

You really need to understand how to use the OD button to manage that gearing, but with ECO your still only going to have 270 ft*lbs to work with once locked up.

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

i'm confused. The lockup numbers you state are the same MPH's that the non-F37 lockup trans numbers are. This is what my trans shift at when I watch the tach. What is the advantage?

I don't understand the 270lb/ft of torque limit with eco tune. The stock torque numbers are 295lb/ft. I thought the eco produced slightly more like 315lb/ft. why wouldn't the tranny be capable of using this power.

arengant · **Posted:** Tue Jul 24, 2012 8:45 am

joelukex4 wrote:

i'm confused. The lockup numbers you state are the same MPH's that the non-F37 lockup trans numbers are. This is what my trans shift at when I watch the tach. What is the advantage?

I don't understand the 270lb/ft of torque limit with eco tune. The stock torque numbers are 295lb/ft. I thought the eco produced slightly more like 315lb/ft. why wouldn't the tranny be capable of using this power.

The f-37 de-tunes the engine to put out less torque, and changed the shift points all to save the TC from destruction. The normal eco-tune goes to 270 ft/lb for the same reason, so if you have a healthy enough TC get the full torque ECO tune (or Hot Tune :twisted:

)

From GDE's site showing Full Torque Eco tune:

Since I do not tow much (or anything really) but I want to be able to if I get a camper, I will stick with the normal TCM tune and use OD off when needed. If I live closer to mountains or tow something heavier/more often I would get the Tow TCM tune

Glend wrote:

Here's a direct quote from the GDE Forum talking about the TCM tune:

"The tune provides 3rd gear lock-up at 35 mph, 4th gear lock-up at 46mph and 5th gear lock-up at 58mph. Shifting is quicker due to allowing lock-to-lock shifts.

The tune also helps with towing by allowing the customer the option to tow at 55mph in 3rd, 4th, or 5th lock-up. 3rd is available by using the OD off button and the trans will pull in 4th if one accelerates to 55mph and sets the cruise or just maintains speed. 5th is possible by accelerating above 58mph and then slowing down to 55mph. It will hold 5th gear down to 52mph. "

You really need to understand how to use the OD button to manage that gearing, but with ECO your still only going to have 270 ft*lbs to work with once locked up.

By the way, GDE doesn't lock up 3rd at 35mph anymore, just 4th @46mph and 5th.

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

I don't have the F37 mod as none of my shift points are above 57MPH. My question is where in the chart does it show that the torque has been reduced from the original CRD by using one of the GDE tunes. All of the torque and HP numbers are increased from the original CRD numbers.

arengant · **Posted:** Tue Jul 24, 2012 1:30 pm

That graph doesn't show the standard ECO-tune torque, they did have a table on the website but I am not sure if it is there as it won't display on my current computer. See if this works: http://www.greendieselengineering.com/forum/posts/list/20.page

301 ft/lb max stock pre-f37, 335 with the ECO-FULL TORQUE tune, so not a huge jump for you

joelukex4 · **Joined:** Thu Sep 29, 2011 4:54 pm **Posts:** 386

It appears that mine still has the pre-F37 settings (first & second columns) and probably no F31 after talking with Keith. This means my torque output is greater than the locked 260lb/ft. I had no shutter and the Liberty pulled hills towing with no problems. The next question is FT ECO or standard ECO.

Klem531 · **Posted:** Tue Jul 24, 2012 11:28 pm

joelukex4 wrote:

It appears that mine still has the pre-F37 settings (first & second columns) and probably no F31 after talking with Keith. This means my torque output is greater than the locked 260lb/ft. I had no shutter and the Liberty pulled hills towing with no problems. The next question is FT ECO or standard ECO.

This is where I'm undecided also. I did put a call into Keith at GDE and explained my situation. He recomended I go with the ECO tune due to the fact that I have F-37 downgrade, he did say that I could probably get away with the FT ECO tune as long as I drive sensably and back off If there is shudder.

papaindigo · **Posted:** Wed Jul 25, 2012 7:28 am

IMHO the post F-37 torque convertor, which was pretty much stock after the early 2005 TC with the plastic part started failing, is marginal. To put it bluntly it was the DCJ bean counter way of "fixing" the fact that the 2.8L in its original configuration put out too much torque for either the "plastic" TC or its immediate replacement to handle. Both of which I'd bet a REALLY good 6-pack DCJ was quite aware of from the get go. Unfortunately the corporate response was to ditch the obviouisly defective "plastic" TC and replace it with one that the bean counters "thought" would work and then when that did not work DCJ took the cheap fix route of detuning the engine and TCM tune rather than fixing the real problem by replacing the TC with something like the Euro. Neat way of transferring the cost of corporate and bean counter cheapness down the road to the customer as the stock post F-37 is just good enough that it won't fail during the warranty period unless pushed hard.

Long winded way of saying the post F-37 TC you have is "ok" and will last "ok" as long as not pushed regardless of tune. Proof of point; when geordi and I installed my GDE Stage 2 turbo with that TC, which had never shuddered, I experenced instant very apparent shudder within the 1st 100' of pavement outside his location under hard acceleration. Subsequently I drove for about a month with zero problems just using a light foot and of course getting no benefit from the new turbo. I probably could have continued to do so but went for a "real" solution which was Suncoast although a Euro probably would have been ok.

The point being that if you tow a lot, push the vehicle a lot, go with a "hotter" tune and drive like you have that tune you will eventually need a new TC so start saving $s for the TC and install. How soon you will need that TC depends on how you drive and a bit of luck.

Keith's point is spot on.

CRD05il · **Posted:** Mon Jul 29, 2013 11:08 pm

Klem531 wrote:

papaindigo wrote:

You have a bit of flex on scheduling the TB but I wouldn't go much over 100k. FYI ID parts has a decent price on the parts for a complete TB job but I'd recommend adding a serpentine belt into the mix since you have to pull it off anyway. Also consider a fan shroud mod to make future access easier (if you cannot find that link email me)..

I have that kit on my wish list at ID parts. :mrgreen:

(My wish list is large and...growing) :mrgreen:

Seems to me I read somewhere that there is a higher quality water pump available than the one that comes with the kit from ID parts but I cant recall where exactly I saw this. Can anyone confirm or deny this? My plan is to change the timing belt, Water pump etc. as well as upgrade to silicone hoses at the same time. I haven't read about the shroud mod yet, I will research that today, thank you for the suggestion. If there is anyone in the North West Indiana region with tools to loan or rent. Please let me know...I'm in Laporte county near the Southern tip of Lake Michigan, also more affectionatley known as the "Armpit of the nation" LOL. I'm only about 45 min from Chicago so I'm certain somebody round these parts would have the tools for the TB change. There is a guy that lives about 2 miles from me with an 05 CRD that I have stopped and talked to but he doesn't have the tools....yet. He did mention he may purchase them. I have my fingers crossed. :ALONE:

I live in Chicago and more then will to help if you need some I just did my belt. I know that jrsavoie has the tools but he said that he is selling them with his Jeep. But I rented them from him . He is south of Chicago.

DOC4444 · **Posted:** Tue Jul 30, 2013 4:40 am

1. If operating properly, ALL GDE TCM tunes, at below 3/4 throttle acceleration, lock the TC at 35 MPH.
The TC continues to STAY locked as long as you do NOT exceed 5/8-3/4 throttle OR you hit the OD button.
The "regular" TCM tune shifts to 4rth at around 46 and 5th at around 58,
The "standard" "Tow Tune" (custom shift points are available) is the same, except the shift to 4rth is delayed to 70.
It will then hold 5th down to around 55. After getting into 5th and then slowing down, you can regain 4rth by hitting
the OD button momentarily and shifting to third, then hitting it again to go to 4rth.
BOTH TCM tunes add 2-3 MPG in the speed range of 35-55 MPH. Above and below that range, there is no difference.
The "tow tune" is essential if you are towing over 3000 lbs in hilly highway terrain,

2. TC "shudder" is usually only an issue at the shift to 5th at 58 MPH.
The "original" ECO tune cleverly reduced torque only during this event. Once the TC has locked in 5th and this speed is exceeded,
the full torque of this tune is available and does not create a problem unless your F37 converter is really bad.
The "full torque" ECO eliminates this feature and may make slightly better fuel mileage than the HOT, which is my preference.
You can get great mileage with a light foot with the HOT and if you are towing heavy, it is the ONLY way to go.

I chassis dyno tested (see my old posts) the original GDE tunes as they were released against InMotion SII back in 2007-2008
and had the privilege of trying out the various prototype TCM tunes as they were developed.

If you have not installed a TC with upgraded springs ("euro" or a very recent Suncoast with "euro" springs), you should only get
the "original" ECO tune. This will save both your TC and, ultimately, your transmission.

Upgrading later to a higher power tune when you replace your TC only costs a few dollars. Keeping the material out that gets
dumped into your fluid when your TC "shudders" is critical. You should alter your driving style to eliminate "shudder".

DOC

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

DOC,

We have released a trans eco tune that does not enable the 3rd gear lockup when in drive 'D'. Several vehicles exhibit booming and lugging vibration through the driveline in 3rd lockup below 40 mph. We have both options available (with or without 3rd LU) in the eco tune and towing tune. I depends on personal preference.

DOC4444 · **Posted:** Tue Jul 30, 2013 12:51 pm

Nice to have that option. Yes, the most vibration is going up a hill at 1400 rpm in third with TC locked. However, I would imagine a lot of the fuel mileage increase between 35-55 would be lost waiting to lock the TC until 46 MPH.

Do you have any data on this?

Thanks as always!

DOC

TCM tune or not to TCM tune...that is the question.

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