Torque Convertor

Larry R. · **Joined:** Sun Jan 21, 2007 1:35 am **Posts:** 92

Has anyone tried to take control of the torque convertor by tapping into the solenoid wire and running it to a switch?

nursecosmo · **Posted:** Sun Jun 29, 2008 2:33 am

Larry R. wrote:

Has anyone tried to take control of the torque convertor by tapping into the solenoid wire and running it to a switch?

What would that accomplish other than haveing the ability to lock the TC? TC lock up is not usually the problem with our transmissions, but rather the shift points which are controlled by the TCM.

Joe Romas · **Posted:** Sun Jun 29, 2008 7:34 am

If you want to live dangerously locate and cut the wire for the "torque reduction" signal from the TCM to ECM :shock:

Let us know how it turns out :wink:

gmctd · **Posted:** Sun Jun 29, 2008 9:14 am

C1-11

Larry R. · **Joined:** Sun Jan 21, 2007 1:35 am **Posts:** 92

control nursecosmo

nursecosmo · **Posted:** Sun Jun 29, 2008 5:07 pm

If you are looking to make the TC kick in at less than 1500 rpm or lower than 4th gear, you will soon be buying a Suncoast TC as well. Even after the F37 was done on my tranny, I can get the clutch to slip right around 55mph and 1500 rpm if I lay on the pedal hard up a steep hill. The TCM controls more than just slip points, it is also controlling the clutch engagement pressure, that is one of the reasons that you can make them slip at lower rpms. If you could find an easy way to increase the pump pressure and then add a TC master switch you would have something cool, which would also probably extend the life of the TC.

DOC4444 · **Posted:** Sun Jun 29, 2008 9:43 pm

Joe Romas wrote:

If you want to live dangerously locate and cut the wire for the "torque reduction" signal from the TCM to ECM :shock: Let us know how it turns out :wink:

I have an InMotion "Stage II" ECM (plus still have the unmodified OEM ECM) in our 2005 CRD. F37 was done prior to our receiving it and it reportedly included TC replacement (DK about the pump). Anyone know how the "torque reduction signal" from the TCM may effect such a reprogammed ECM?

(With the OEM ECM in place, there is really no significant "shudder" when you get on it at 55 to 60 MPH. HOWEVER, with the IM installed, the "shudder" is horrendous and I make every effort to avoid it like the plague. (It basically feels like something will just have to break in seconds.) You can see from my dyno results posted elsewhere on this site that the torque increase is no more than 60 ft/lbs over stock, so the "margin" between being OK to "over the edge" is obviously quite small.

My understanding is that F37 raises the speed at which the TC locks up. Based on my experience, it would be even worse without F37. What I'm really concerned about is that we bought this CRD to tow a 4500 lb trailer (haven't done it yet). I can't imagine towing up a hill pulling that trailer at 55-60 MPH without hitting the OD button and/or downshifting.

Is it absolutely clear that the "shudder" is just the TC and not another part of the transmission or possibly due to not having a lift pump in conjunction with a higher output ECM?

Really appreciate everyone's thoughts.

Best Wishes,

DOC

gmctd · **Posted:** Sun Jun 29, 2008 10:11 pm

Install a cheap lift pump near the fuel manager head, direct-wire it to the LP Fuse, to answer that question - the Suncoast CRD TC is the Hemi version with an aluminum stator, and increased TCC lockup capability - can be increased even more by increasing line pressure via offsetting the pressure sensor - I've not installed the switchable offset for comparison, but it doesn't shudder after lockup in my app with EDGE Trail module

The IM Stage II should have improved shift quality, and possibly TCC lockup, but I have yet to test that - far as TRS, mine has been decomissioned for ~15kmi with no apparent harm, but I have not installed the planned switch for comparison

nursecosmo · **Posted:** Sun Jun 29, 2008 10:45 pm

The F37 can be sort of undone at the 55 to 60mph range by accelerating to 61mph letting it shift into 5th lockup then dropping back to 56mph the rpm will be between 1500 1nd 1600. Apparently DCX realized that the torque was too great at that RPM thus the F37. The fuel starvation issue is a distinct type of shudder usually occurring when letting off of the accelerator or feathering it at around the same speed. long live whoever was the first to suggest a lift pump.

DOC4444 · **Posted:** Sun Jun 29, 2008 11:00 pm

GMCTD,

Is the "fuel manager head" what the fuel filter is attached to?

Thanks,

DOC

gmctd · **Posted:** Mon Jun 30, 2008 12:28 am

Yes - the fuel manager head consists of the filter element, the heater, the Water in Fuel sensor, and the primer pump - remove the hose from the fitting on the engine-side of the fm head, insert electric lift pump, attach second piece of fuel hose and two hose clamps between the pump outlet and the head inlet, tighten'em down, ground one LP wire, run the other to the LP Fuse in the underhood power-center box, and yer good to go............

gmctd · **Posted:** Mon Jun 30, 2008 12:28 am

oops!

Joe Romas · **Posted:** Mon Jun 30, 2008 7:39 am

gmctd wrote:

Yes - the fuel manager head consists of the filter element, the heater, the Water in Fuel sensor, and the primer pump - remove the hose from the fitting on the engine-side of the fm head, insert electric lift pump, attach second piece of fuel hose and two hose clamps between the pump outlet and the head inlet, tighten'em down, ground one LP wire, run the other to the LP Fuse in the underhood power-center box, and yer good to go............

And you'll be so happy with how good it runs you'll want to put on a Cummins pump in the tank :wink:

BlackLibertyCRD · **Posted:** Tue Jul 01, 2008 1:21 pm

here is link to the cheaper mod at the fuel manager head

http://www.lostjeeps.com/forum/phpBB3/vie ... 27&start=0

Uffe · **Posted:** Tue Jul 01, 2008 2:03 pm

gmctd wrote:

oops!

Poor old gmctd - hope that isn't Parkinsons :wink:

Torque Convertor

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