GDE "Hot" tune with stock TC

litton · **Posted:** Wed Nov 25, 2009 2:12 pm

I know GDE recommends that the hot tune be used with a new TC but I'm thinking about it anyway.

I have the F37 but so shudder, but no indications of a bad stock TC which may or may not mean anything. However, I do have an extended warrenty for 5 years....so, you can guess what my logic is.

In addition, I won't be pushing it hard and i't mainly my light-footed wife that drives it so I guess I wondering how long I might have before it goes T.A. I guess the only reason I'm even looking at it is because it's there and sometimes I feel a bit spirited. Plus, the ability to pass at hwy speeds should be improved.

Any thought would be appreciated.

95BadBoy · **Posted:** Wed Nov 25, 2009 3:14 pm

I believe "Flman" has the hot tune on one of his KJ's with a stock TC. May want track him down & shoot a PM to him if he doesn't post up here first.

DOC4444 · **Posted:** Wed Nov 25, 2009 10:15 pm

If you are not towing, it is easy to "drive around" the shudder problem. You just accelerate to 60+ in a lower gear/OD off, then back off and shift up past the lockup point. The TC will fully lock with minimal load being applied. You can then resume power application tofurther increase speed without shudder. I used to have the IM SII with the F37 TC. Gentle acceleration in Drive would blur my vision at 58 MPH. However, as long as you do not allow the TC to shudder, you will do no damage.

If you tow any weight, I would strongly suggest the ECO until you upgrade to the "euro" TC.

DOC

litton · **Posted:** Thu Nov 26, 2009 10:36 am

I don't do any towing with the Liberty and have never experienced any "shudder" so I shouldn't have to worry. Unless, of course, the hot tune induces the problem. I suppose I should pop into the dealer and make sure all my ECU flashes are up to date. There is no sicker on the module so I have no idea which, if any where done.

flman · **Posted:** Thu Nov 26, 2009 10:47 am

You can get the HT and add "Dr. Tranny Instant Shudder Eliminator" or shudder the hell out of it and get the Euro TC with you warranty. :twisted:

I have had no shudder just by using the shudder eliminator. And you can feel the torque of the HT at any speed.

DOC4444 · **Posted:** Thu Nov 26, 2009 10:54 am

FIRST, have a dealer run a full "VIP" report on your VIN and give you a printout. This will show the full (factory) service history, recalls and build details. If you have miraculously avoided the F37 reprogram of your TCM, stay away from the dealer until you can pickup a cheap used TCM that has already been neutered. Put that one in before going to the dealer.

BTW, since the "euro" TC is now the "standard" TC for US CRDs, you should be able to get that one installed if you have not already had the TC recall done. Just make sure they have the right part number.

YES, the HOT tune will give you massive shudder that you currently have no clue about under the conditions I described in my post above if you do not have the latest TC installed.

DOC

DOC4444 · **Posted:** Thu Nov 26, 2009 11:09 am

flman,

2 tubes of Dr. Tranny slightly changed the freqency of the shudder I experienced with the IM SII and the F37 TC, but it had no effect on the violence of it. I'm glad it has worked well for you, but it does not for everyone. However, I don't think it is likely to hurt anything to try it.

Regarding warranty replacement, I'm be a bit concerned if you don't have a stock ECU to put in when you bring it to a dealer. (I kept the OEM and put it in whenever ours goes to the dealer.) GDE assures us that their tunes are undetectable at a dealer, but what if someone actually has some experience with these things and notices the massive power increase? We have a 7 year, 100K premium factory warranty that cost close to $2K. I'd hate to blow that when you can pickup a spare ECU on the used market for usually no more than$150.

DOC

DarbyWalters · **Posted:** Thu Nov 26, 2009 9:26 pm

I had to use two tubes of Dr Tranny and it stopped the shudder unless I am cruising in the 1800-2200 rpm range and then floor it. Otherwise it (Dr Tranny) made the shudder virtually disappear. If I do feel it coming on I just back off a bit and no problem. I have the HOT Tune with the STOCK TC

dieseldoesit · **Posted:** Fri Nov 27, 2009 4:14 pm

Darby, have you towed anything with your setup?

I am looking at getting one of the tunes. I want the hot tune, but I use my liberty to tow snowmoibles up the pass all winter long. I will have enough to worry about and I don't want to be concerned with shudder. I am also cheap, and it looks like to have a shop install the converter, you are looking at 4-5 hundred bucks, on top of the converter cost and the gde tune. 1k is a lot of money.

Good thread.

DOC4444 · **Posted:** Fri Nov 27, 2009 4:51 pm

You only lose about 30 lbs/ft of peak torque by going with the ECO tune and you get the benefit of the incredily trick "momentary torque reduction" feature around 55-59 MPH where the real "shudder" problem occurs. This totally eliminated the shudder I had with the IM SII and F37 TC. And, you can always upgrade to the HOT for just a few bucks when you put in the "euro" JK TC.

If you are frequently towing heavy, you will destroy your TC (and possibly damage your trans as well from all the debris) if you run the HOT tune without the latest TC. I would strongly suggest the ECO for you for now.

Also, if you do not have SEGR, the GDE tunes eliminate the need for it. SEGR is a brilliant piece of work, but it cost me $400+ by the time I had it built and successfully installed. Keeping the EGR closed most of the time is essential, though, so you need to take care of it one way or the other.

DOC

litton · **Posted:** Sat Nov 28, 2009 10:00 am

I might have spoken too soon about the stock TC giving me no trouble. When I drove it to the store yesterday I noticed a metallic rattle from the vicinity of the tranny when it's in drive at idle....wonder if that's the TC going T.U.

flman · **Posted:** Sat Nov 28, 2009 8:52 pm

litton wrote:

I might have spoken too soon about the stock TC giving me no trouble. When I drove it to the store yesterday I noticed a metallic rattle from the vicinity of the tranny when it's in drive at idle....wonder if that's the TC going T.U.

Are you up around 80K miles? That is when the left motor mount starts making a noise. Mine sounds like nuts grinding.

litton · **Posted:** Sun Nov 29, 2009 9:36 am

I'm at 37K and it sounds like marbles in a tin can. But not all the time, just once in awhile. Ireally really hate intermitant odd noises.

Joe Romas · **Posted:** Mon Nov 30, 2009 7:56 am

litton wrote:

I'm at 37K and it sounds like marbles in a tin can. But not all the time, just once in awhile. Ireally really hate intermitant odd noises.

Could be loose flex plate to torque converter bolts :lol:

bigcoupee · **Posted:** Sun Dec 20, 2009 11:29 pm

I've go the hot tune with the suncoast, and get tons of shutter what a waste of 1000 bucks for the suncoast. Come to think of it I'm going to call them and witch.

danoid · **Posted:** Mon Dec 21, 2009 10:07 am

flman wrote:

You can get the HT and add "Dr. Tranny Instant Shudder Eliminator" or shudder the hell out of it and get the Euro TC with you warranty. :twisted:

I have had no shudder just by using the shudder eliminator. And you can feel the torque of the HT at any speed.

I don't believe any additive will cure this shudder. It's a matter of springs bottoming out on the torque converter damper. Only stiffer springs will help. That's why a torque converter was released that had stiffer springs in the damper.

There are other shudders however. I used to have the one that came only after a hard acceleration, then trying to maintain a steady speed. GDE cures that one. I think another one is caused by engine mounts. That one is really frightening, but rare. You need high torque, low rpm, and time (like going up a hill and trying to gently accelerate). The fix for that one, is to punch it and downshift.

DOC4444 · **Posted:** Mon Dec 21, 2009 7:37 pm

Bigcoupee,

Sorry to hear you are another Suncoast customer with shudder problems when using one of the highest output tunes (GDE "HOT" or IM SII). (You are the first person I am aware of who has mentioned this with GDE "HOT" and a Suncoast TC.) I heard too many reports of this with Suncoast and waited for a better approach. It looks like the "euro" TC may be it. We now have several hundred miles of heavy towing under our belt with no signs so far of any shudder.

However, while I didn't go down exactly the same expensively misguided path you did, I did lay out a total of $450 for SEGR which is no longer needed with a GDE ECU and spent $450 for an IM SII tune plus "cloning", so I can relate to your financial pain.

DOC

nursecosmo · **Posted:** Tue Dec 22, 2009 11:34 am

danoid wrote:

flman wrote:

You can get the HT and add "Dr. Tranny Instant Shudder Eliminator" or shudder the hell out of it and get the Euro TC with you warranty. :twisted:

I have had no shudder just by using the shudder eliminator. And you can feel the torque of the HT at any speed.

I don't believe any additive will cure this shudder. It's a matter of springs bottoming out on the torque converter damper. Only stiffer springs will help. That's why a torque converter was released that had stiffer springs in the damper.

There are other shudders however. I used to have the one that came only after a hard acceleration, then trying to maintain a steady speed. GDE cures that one. I think another one is caused by engine mounts. That one is really frightening, but rare. You need high torque, low rpm, and time (like going up a hill and trying to gently accelerate). The fix for that one, is to punch it and downshift.

The TC shudder is not entirely damper related if even at all. The fact that Dr Tranny reduces or cures it demonstrates that it is mostly clutch related, as a friction modifier has no effect on spring rate. The new TC supposedly has stiffer dampers, but more importantly it has a better clutch. :2cents:

powerstroker67 · **Joined:** Thu Dec 18, 2008 9:21 am **Posts:** 19

We do a great deal of work with Suncoast on Ford,Dodge, and Chevy diesel transmissions on a daily basis and Ron(@Suncoast) has said there was a update made to the 545RFE kits recently. Ron has an very big interest in advancing the performance of this 545RFE tranny as he owns a Dodge p/u and car with this tranny in it. He has done some amazing things including turning this 5 speed into a 6 speed in one Dodge S/C Hemi. The change to help/fix the shutter was made in the pump and Transgo kit being installed. I installed the Suncoast stuff in my wife's Liberty when we got it at the beginning of this year, just haven't gotten a change to pull the tranny out and do it again. I have done a few 545RFE's in Hemi Dodges with the updated parts in the Transgo/Suncoast kit and had no issues. It use to be the pump had to be machined to be modified to prevent this, now this kit installs without machine work.

GDE "Hot" tune with stock TC

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