Question about towing with pre f37

Joe Romas · **Posted:** Fri May 28, 2010 7:09 am

Does anyone have towing experience with original, pre F37, tcm flash. I'm interested in knowing how it handles a grade when towing. With the F37 flash most of us know it will jump from 5th to 3rd and in a few seconds lock the TC in third.

Does the pre f37 flash utalize 4th gear at all in the above situation?

A couple of things about the newly released GDE TCM flash don't sound good for me. The first is shifting without releasing the TC clutch and the second is droaning that Doc444 mentions because of the low lockup speeds. I do remember the droaning in the first 2 weeks I owned my crd before it was flashed back in June 06 :roll:

flman · **Posted:** Sun Jun 13, 2010 3:08 pm

Joe Romas wrote:

A couple of things about the newly released GDE TCM flash don't sound good for me. The first is shifting without releasing the TC clutch and the second is droaning that Doc444 mentions because of the low lockup speeds. I do remember the droaning in the first 2 weeks I owned my crd before it was flashed back in June 06 :roll:

I have no complaint with the shifting with out releasing the clutch, it might be a problem on a stock TC, but not on the Euro.

Of course you are going to have a droan with low RPMs, mine feels more like a truck now, it is almost at the point of lugging but not quite. I was a little apprehensive of the tune, but I might just get used to it?

Joe Romas · **Posted:** Mon Jun 21, 2010 2:31 pm

Dosen't anyone tow with a pre f-37 tune :?:

CATCRD · **Posted:** Mon Jun 21, 2010 3:36 pm

Joe Romas wrote:

With the F37 flash most of us know it will jump from 5th to 3rd and in a few seconds lock the TC in third.

Pre F37 does the same thing - drop to third.

flman · **Posted:** Mon Jun 21, 2010 4:42 pm

At what speed does Pre f37 shift into 5th? 59 MPH?

CATCRD · **Posted:** Mon Jun 21, 2010 4:50 pm

Upshift to 5th at 58mph. Downshift out of 5th at 55.

flman · **Posted:** Mon Jun 21, 2010 5:19 pm

CATCRD wrote:

Upshift to 5th at 58mph. Downshift out of 5th at 55.

I don't like that, I guess I will keep the GDE tune.

Joe Romas · **Posted:** Mon Jun 21, 2010 6:29 pm

flman wrote:

At what speed does Pre f37 shift into 5th? 59 MPH?

Yes, 59. But F37 also shifts at about 59 but into 4th :lol:

stoutdog · **Posted:** Mon Jun 21, 2010 7:29 pm

Joe Romas wrote:

flman wrote:

At what speed does Pre f37 shift into 5th? 59 MPH?

Yes, 59. But F37 also shifts at about 59 but into 4th :lol:

IIRC, F37 shifted into 4th at about 53, and 5th at 61...

Joe Romas · **Posted:** Tue Jun 22, 2010 7:54 am

stoutdog wrote:

[ F37 shifted into 4th at about 53, and 5th at 61...

Are you talking gps indicated mph or speedo mph? Per my speedo mine shifts as I indicated.
To eliminate confusion if everyone used speedo figures when talking about shifting we could compare apples to apples because even tires can make a difference in actuall speed. But the TCM uses the same info as the speedo to shift

CATCRD · **Posted:** Tue Jun 22, 2010 10:17 am

stoutdog wrote:

Joe Romas wrote:

flman wrote:

At what speed does Pre f37 shift into 5th? 59 MPH?

Yes, 59. But F37 also shifts at about 59 but into 4th :lol:

IIRC, F37 shifted into 4th at about 53, and 5th at 61...

F37 is 4th at 50 (same as pre F37) and 5th at about 61.

flman · **Posted:** Tue Jun 22, 2010 4:47 pm

Joe Romas wrote:

stoutdog wrote:

[ F37 shifted into 4th at about 53, and 5th at 61...

Are you talking gps indicated mph or speedo mph? Per my speedo mine shifts as I indicated.
To eliminate confusion if everyone used speedo figures when talking about shifting we could compare apples to apples because even tires can make a difference in actuall speed. But the TCM uses the same info as the speedo to shift

X2 I don't know why every one uses GPS, not like the tranny has a GPS receiver for info :ROTFL:

stoutdog · **Posted:** Tue Jun 22, 2010 6:35 pm

flman wrote:

Joe Romas wrote:

stoutdog wrote:

[ F37 shifted into 4th at about 53, and 5th at 61...

Are you talking gps indicated mph or speedo mph? Per my speedo mine shifts as I indicated.
To eliminate confusion if everyone used speedo figures when talking about shifting we could compare apples to apples because even tires can make a difference in actuall speed. But the TCM uses the same info as the speedo to shift

X2 I don't know why every one uses GPS, not like the tranny has a GPS receiver for info :ROTFL:

I used the GPS, not the speedo. Speedo shift into 5th was around 64mph, nobody claims the F37 programs it there. It also downshifted at an indicated 60mph (GPS - 57mph) - again, nobody claims the downshift was there either.

Joe Romas · **Posted:** Wed Jun 23, 2010 8:29 am

[quote="stoutdog] Speedo shift into 5th was around 64mph, nobody claims the F37 programs it there. It also downshifted at an indicated 60mph (GPS - 57mph) - again, nobody claims the downshift was there either.[/quote]

As the originator of this post my question was about towing with a pre f37. Most of us already know that with f37 the shift to 5th is at 64 and the shift back down actually occures more like 59 PER THE FACTORY EQUIPED SPEEDOMETER :furious:

So your "Nobody claiming anything about F37" is irrelevent to my question and every CRD came with a speedometer so it just may be a good universal figure to use. Unless the subject is about putting on bigger tires and how it changes the speedo error.

The kind of information I'm looking for is does it take a larger percentage of throttle opening before downshifting :lol:

And for everyone's benefit I learned that GDE offers a "full torque Echo tune", not the HOT tune, that does not reduce the torque at the critical rpms of the original TC. After talking with Keith this may be the solution I'm looking for :CAMPING:

Snowy · **Joined:** Sat Jan 16, 2010 3:00 am **Posts:** 42

For the small amount that it's worth, I tow my 2 jet-skis (750lbs each) to and from L.A./Vegas and then to Lake Powel (Utah/Arizona border) all Summer long.

My guess is that I have a "post" transmission with a stock torque converter. I have no idea what the speeds are at which it shifts, nor do I care. Why? Because it gets the job done effortlessly, economically and reliably. I use the on-board speedo with stock everything and have an Eco-tune, which is great.

Just thought a bit of "un-modified (but for the Eco-tune)" input might help.

Oh, yeah, no problem on the launch ramps either. :wink:

Joe Romas · **Posted:** Fri Jun 25, 2010 7:56 am

Snowy.

Thanks for the input. Gussing with the two jet ski at 750 each (1500) and maybe 500# for assuming a light trailer your around 2000# or less so you should have no trouble.

With my 3000# empty and around 3500# loaded travel trailer trying to maintain a true (indicated 65) 60 mph on grades (not even hills) it's a constant 5-3-5-3 shifting unless the od button is pushed then your around 55 or less and a pain to other motorists along with a screaming engine :ALONE:

Since this transmission is also used in the Hemi powered Ram pickup trucks it should be able to handle the chore better then what Chrysler gave us :dizzy:

Joe

Question about towing with pre f37

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