GDE TCM for sale... (on hold, in test)

DynoPax · **Posted:** Mon Jul 02, 2012 12:15 pm

Gentlemen,

I am putting my GDE-programmed TCM for sale, for $200.00, excluding shipping costs... I figured it did not fulfill my needs, as I mostly do highway mileage and the tune is more efficient for city driving and fuel saving. Besides, I purchased a camper and the low-end torque on shift changes is detrimental to proper pull of such weight (3500lbs). If anyone is interested, PM me and we can make arrangements for shipping & payment...

DOC4444 · **Posted:** Wed Jul 04, 2012 10:36 am

The "tow tune" solves that problem by keeping you in 4rth gear to 70 mph.

DOC

ChooChooman74 · **Posted:** Wed Jul 04, 2012 11:04 am

DOC4444 wrote:

The "tow tune" solves that problem by keeping you in 4rththe gear to 70 mph.

DOC

It would be nice to be able to hook up a tow/haul button where it will hold the gears longer when towing, yet shift sooner when light and going for fuel economy.

audiboy86 · **Posted:** Wed Jul 04, 2012 11:37 am

Umm someone didn't read the tow tune because it basically turns you overdrive in to your tow button.

DOC4444 · **Posted:** Wed Jul 04, 2012 1:25 pm

If you use more than 65% throttle, the gears are "held" longer. When not pulling a heavy load, you don't need that much throttle, so it does basically do what you suggested.

The OD "off" button function does not change with the "tow tune". It simply puts you into 3rd. However, there is a trick to it. If you are in 5th (2nd OD) cruising at 70, slow to say, 60, hit a hill and want 4rth without opening the throttle (sic) more, you can hit the OD button twice and you will be in 4rth.

DOC

DynoPax · **Posted:** Wed Jul 04, 2012 2:05 pm

DOC4444 wrote:

The "tow tune" solves that problem by keeping you in 4rth gear to 70 mph.

DOC

...But the 3rd gear lockup does not help, neither will shift changes between 1st, 2nd & 3rd. The drop is too low (1400-1500 RPM) with a load, it chugs and vibrations can be felt through the transmission...

geordi · **Posted:** Wed Jul 04, 2012 2:20 pm

DynoPax wrote:

DOC4444 wrote:

The "tow tune" solves that problem by keeping you in 4rth gear to 70 mph.

DOC

...But the 3rd gear lockup does not help, neither will shift changes between 1st, 2nd & 3rd. The drop is too low (1400-1500 RPM) with a load, it chugs and vibrations can be felt through the transmission...

That isn't caused by the tune... That sounds suspiciously like torque converter shudder. You WANT the engine low in RPM because it is a diesel. (And a tune can't change the RPM after a shift, that is ENTIRELY done by the gearing) The torque converter is shuddering because the engine is pushing more power (It is a diesel!) than the crap converter can hold against, you are feeling the clutches slipping.

The stock program just changes the shift signalling, and lowers the engine output power - DETUNING YOUR ENGINE IS NOT THE ANSWER, but it is what Chrysler Bean Counters decided to do. Did they then change the marketing to tell everyone that they had a less-capable engine than the one they THOUGHT they bought? Of course not. Better to just hide the fact that they chose a crap component to put behind a strong engine.

papaindigo · **Posted:** Wed Jul 04, 2012 3:21 pm

If the vibration you feel is sort of like, without the bucking, a newby learning how to operate a clutch it's torque convertor shudder. Couple of checks with the trailer in tow 1) when you feel the problem press the OD button or drop a gear; if the problem goes away it's shudder or 2) from a dead stop stomp the go pedal; if the problem immediately appears it's shudder.

The OEM torque convertor isn't the greatest but stoutdog and I just drove his 06 (stock size tires, GDE EcoTune, and GDE regular TCM tune with a stock torque convertor) from Tempe, AZ to Tallahahasse, FL, on I-10 with the interior passenger seat and rear fully loaded pulling a 5x8" uHaul (900 lbs empty) containing 1,000 lbs + of stuff with zero transmission issue. Put it in drive and drove, no shudder, no temp above dead vertical, etc. Now I'll admit I-10 is the "flatest" Interstate in the country but it does have hills so there were occasions where the tranny down shifted and I'll also admit we kept the rpms in the 1800 range (60-65mph) max which had us solidly in top gear lockup.

jws84_02 · **Posted:** Wed Jul 04, 2012 7:54 pm

Wait... I'm confused.

I pull about 2000 lbs behind my crd. I'm getting the Eco tune and am debating the tcm tune. I don't do much city/town driving.

My question is, there are two tcm tunes? What's the difference and benefits of both?

DOC4444 · **Posted:** Wed Jul 04, 2012 8:12 pm

There are. Search the site for extensive discussion of this. I think over 2000 lbs, tow tune is almost a must. (We tow 5K.) Below, maybe not. The main inconvenience is if you plan to drive at 65 without towing, you have to go to 70 to get it into 5th, then slow back to 60-65. If you don't do that, it will never shift to 5th.

DOC

DynoPax · **Posted:** Thu Jul 05, 2012 2:33 pm

OK, let me clarify a few things here:

1- I know the difference between TC shudder and drivetrain vibration. I replaced the OEM TC with the Euro 2 years ago and have not had an issue since...
2- The vibrations I refer to are what you would normally expect when pulling a heavy load, I only find it more pronounced with the regular TCM tune, again due to lower shift points and lower RPM when engaging the lockup...
3- Obviously, I disengage the OD when towing such a load, but being caught at the start of a steep hill in 2nd gear at 1500RPM does not yield enough torque, hence the drivetrain vibration...
4- My problem could also be engine-related, but have not dwell into that possibility yet, with no apparent signs apart from turbo seeming to lack a bit of oumph! when doing WOT (compared to before)

Finally, I know of Keith's offering of a tow version of the TCM tune. He also can provide custom fine-tuning, which is great (like all his offerings) :google:

I am mostly debating the necessity of spending yet $300 for another tune. I have spent a LOT on the Jeep already and feel I could do away with the OEM TCM for now. With this said, I am still open to reconsider and go ahead with the tow tune but I will make sure first this is the $oundest decision I can take...

geordi · **Posted:** Thu Jul 05, 2012 3:42 pm

I think you might not recognize the difference between TC shudder and anything else that you think you do.

Your comment on #3 of "2nd gear and 1500 rpm doesn't yield enough torque - hence the drivetrain vibration" points this out to me - There is no possibility of torque converter lockup in 2nd gear, and you should be getting PLENTY of torque because 1500 is just below the torque peak for the engine. What MIGHT be happening is a reduction in fluid pressure, causing the converter to slip. If, as you suggest, you did not have enough torque to pull the load (and your converter was NOT slipping), the result would be that the load would pull the engine RPM down, and the engine would stall.

I'm probably the person on here that has pulled the heaviest loads with my CRD. I'm talking about a 60kW towable generator shown here:
http://www.cat.com/power-generation/rental-power/spec-sheets and click on the XQ60 for the full specs - Fully loaded, 6980 lbs. On that generator job, I also had to carry 500 feet of 1.25-inch diameter copper cables, which weigh in at about 2 lbs/foot or so, so I actually was towing almost 8000 lbs.

I have the GDE Eco-Tune, and the first TCM tune that Keith developed. This is not (as far as I am aware) anything special for towing. I DO NOT HAVE the "euro" converter, I have one that I bought from a transmission / engine shop that I trust. According to them, there isn't anything special about this converter, but it doesn't have any plastic parts in it at all.

Pulling that load, there is a bridge that I have to cross every day that is 1 mile long end-to-end, and rises about 280 feet above the water line. On one side of this, it starts only about 10 feet above the water. The other side, the approach is much shorter before entering the bridge, but you still have to make that climb. I don't know the actual grade, but I would suspect it is above 6% fairly easily.

My torque converter (or my driveline) do not shudder, vibrate, complain, break, stall, or anything else on this pull. It IS a tough pull, and I was only able to do it at about 55mph, and slowing down. I do not put my foot to the floor, but I do know that the EGT was pushing 1500 (pre-turbo) for that, and I was about 75% into the throttle. Going WOT just made the transmission drop into the next lower gear (2nd), skyrocket the RPM... And did exactly nothing for the speed or power of the pull - It only made a lot more engine noise and EGT.

1500 RPM is not too low to pull a grade, but it IS possible to out-power your torque converter still. What you think is driveline vibration... Where do you think that is coming from? Torque converter shudder when you are in a low-load situation, not towing anything... Would not be terribly violent feeling, because the output power is relatively low. When towing, ESPECIALLY when pulling a decent load (and I don't consider your trailer that heavy at all), the comparative POWER being output by the engine is much higher at EVERY SINGLE RPM level, so when the torque converter slips, why wouldn't that slippage be more violent?

You are experiencing torque converter slip, I'm sorry to say. Maybe an increase in line pressure would solve this for you. Maybe your dealer didn't actually put in the Euro converter. Maybe your valve body in the transmission has a tiny crack somewhere or one of the solenoids is leaking, and venting the pressure back to the pan. I don't know on any of that, but I do know that you can't have "driveline vibration under load" without having SOMETHING slipping somewhere. Every time it slips, it will try to catch itself - and slip again, and catch itself again... Causing a violent shuddering. The transmission itself is heavy gears. They don't slip, they break. If your CRD still moves - The gears aren't broken. Same for the transfer case. There isn't ANYTHING in the transfer case that allows slippage to the rear wheels. Same for the differential. Gears only. The ONLY PLACE that slip is allowed or could come from - the torque converter.

papaindigo · **Posted:** Thu Jul 05, 2012 4:27 pm

As to that bridge grade. It's US 17 across the main Savannah River shipping channel and geordi's right it's one steep mother even not towing. If he has pulled up that grade with that load and no driveline vibration then it sounds like your system has a problem if your experiencing vibration with a much smaller tow.

DynoPax · **Posted:** Mon Jul 09, 2012 2:39 pm

Thank you for sharing your view on the subject, it gives some perspective to what I am experiencing :google:

Based on your comments, I get more & more the feeling my Jeep is under-achieving in a few departments. I have detected what might be an air leak with the turbo, as I can hear a hissing sound on top of the usual whistling at lower speed. I'll do a few tests involving the intake, CAC and hoses...

Also, during my week-end trip to the lake, I also found the transmission not responding to kickdown when attempting to double slower vehicles. Where it usually jumped by downshifting and turbo boost, now it just increase speed in a very linear fashion. I attempted to force it a few time but to no avail, won't respond to my demand...

In regard to the TC, I did the change myself. I believe the only way to validate if it was the new Euro-spec was with correct part number inscription on the box, which was the case. Before the change, I could easily replicate the infamous shudder, by doing WOT in hills, where you could literally feel the rattling in the transmission, almost like an impact tool. This is not the case here. Geordi's mention of line pressure could be an interesting path to follow. The pump may have started to show signs of failure. I have not seen any leaks under the tranny when I did the transmission oil change back in May and it still is the case.

Hopefully, I can find the source(s) of issue :frankie:

and bring the Precious to behave like a good-mannered girl! :JEEPIN:

papaindigo · **Posted:** Mon Jul 09, 2012 2:51 pm

If you hear a hissing sound and don't really feel a good turbo boost I'd recommend pulling both intercooler hoses and check for leaks especially on the bottom side (if you have the OEM hose pull the woven cover and while in there see if your airbox to turbo hose is ripped on the bottom just in front of the turbo), you might also want to inspect vacuum hoses around the black tower looking thing in back of the air box including the hoses under/behind the coolant tank (at least one member had a melted hose) and you might try the boost pressure solenoid bypass (if the latter improves things replace the solenoid)

Joe Romas · **Posted:** Mon Jul 09, 2012 8:16 pm

DynoPax wrote:

...The drop is too low (1400-1500 RPM) with a load, it chugs and vibrations can be felt through the transmission...

Have you checked your charged air hoses? You need to remove them to properly check them. Then you may as well put on a set of Samco hoses :lol:

I have the Euro TC and new style front pump. I also have both PRE and POST F37 TCM's along with the ECO Full torque tune :BANANA:

Further I know what TC shudder feels like. Your talking about plain old fashioned lugging the engine :shock:

Before this is over I'm sure someone will suggest a new style fuel head will solve the problem :-)r

When towing our 3500# camping trailer with the PRE f37 TCM I experience exactly the too low or lugging sensation your talking about with very little pedal and slow speeds :juggle:

I find the F37 TCM as good as your going to get for towing at least for our 3500#s and the roads I drive.
For me there's no reason at all to have 70 mph as the final shift point.
With the combination of the full torque tune and F37 TCM it's even possible for me to keep the transmission in 4th gear in a certain speed range :SOMBRERO:

Without the trailer I prefer the PRE F37 TCM for better shift points and do get maybe 2 mpg better city driving.

My 1993 VW Eurovan had a switch on the dashboard that altered between lower and highter shift points but I never towed with it or needed it for heavy loads like now :dizzy:

It sure beat swapping TCM's before and after a camping trip :5SHOTS:

Tony P. · **Posted:** Mon Jul 09, 2012 9:29 pm

geordi wrote:

Pulling that load, there is a bridge that I have to cross every day that is 1 mile long end-to-end, and rises about 280 feet above the water line. On one side of this, it starts only about 10 feet above the water. The other side, the approach is much shorter before entering the bridge, but you still have to make that climb. I don't know the actual grade, but I would suspect it is above 6% fairly easily.

A picture is worth a thousand words, was just there last weekend!

geordi · **Posted:** Mon Jul 09, 2012 11:52 pm

If you came through that way, why didn't ya drop me a line? You drove right past me (or within about 3 miles) on 17 there.

And yep - That is the bridge. Steep bugger, isn't it? I never have to worry about finding an on-ramp for an Italian tuneup, I just hammer it on that bridge once in a while.

Tony P. · **Posted:** Tue Jul 10, 2012 12:19 am

Sorry about not dropping a line I was driving back from New York (Family visit) and that was one of the places we stopped on the way back down. We spent about half of the day there sight seeing. It is a steeeep bugger! I do go near their in SC on occasion next time I'll drop a line.

DynoPax · **Posted:** Tue Jul 10, 2012 9:52 am

Joe Romas wrote:

DynoPax wrote:

...The drop is too low (1400-1500 RPM) with a load, it chugs and vibrations can be felt through the transmission...

Have you checked your charged air hoses? You need to remove them to properly check them. Then you may as well put on a set of Samco hoses :lol:

I have the Euro TC and new style front pump. I also have both PRE and POST F37 TCM's along with the ECO Full torque tune :BANANA:

Further I know what TC shudder feels like. Your talking about plain old fashioned lugging the engine :shock:

Before this is over I'm sure someone will suggest a new style fuel head will solve the problem :-)r

When towing our 3500# camping trailer with the PRE f37 TCM I experience exactly the too low or lugging sensation your talking about with very little pedal and slow speeds :juggle:

I find the F37 TCM as good as your going to get for towing at least for our 3500#s and the roads I drive.
For me there's no reason at all to have 70 mph as the final shift point.
With the combination of the full torque tune and F37 TCM it's even possible for me to keep the transmission in 4th gear in a certain speed range :SOMBRERO:

Without the trailer I prefer the PRE F37 TCM for better shift points and do get maybe 2 mpg better city driving.

My 1993 VW Eurovan had a switch on the dashboard that altered between lower and highter shift points but I never towed with it or needed it for heavy loads like now :dizzy:

It sure beat swapping TCM's before and after a camping trip :5SHOTS:

Bingo! Lugging is the correct term here, and what I feel is happening... On the intake side, I already have the Samco's and a new intake hose (air box to turbo) after finding a nice rip at the bottom of the previous one. I will remove everything again for closer inspection and do a pressure test on the intercooler, that should help in pinpointing the culprit, if any. Vacuum and solenoid are also on the test & inspection list...

I too like the F37 if only for the smoother shifts. But I never got the definitive answer for a nagging question: Assuming the F37 had an impact on the ECM by lowering HP output, would it still have the same effect on GDE ECM tune as well?

GDE TCM for sale... (on hold, in test)

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