Trans failures

[Ramunit]

So Sil and Scott are yall both saying I should remove the resistor supplied in the Shift kit?? I agree an over all spike of pressure cant be good for it, but with the stiffer springs supplied to rebuild the valve body I would almost assume it was needed. Im courious about failures so i can try preventing them as long as I can, but that being said im sure all my 4lo racing in the dirt blowing through the gears is soon to catch up with it.

I'm not saying anyone should or shouldn't remove the resistors, it has to be your doing. Personally I (myself) would not blindly add LP with a resistor because you're fooling the ECU to bump up every shift point, up and down including reverse. What if one particular stock shift point LP was at it's upper limits and you are increasing everything globally, some exceed the limits and some don't get enough. A great example is if reverse is 220 stock and you up it with a resistor there would be a huge clunk going from P to R. Who wants that as we know that can't be good and that's at idle speed. What about the pressures at WOT? I personally don't want to exceed the pressure maximums blindly for 1-2, 2-3 up or for that matter any downshift. In my eyes the only way to do it right is to have the ability to monitor LP and adjust accordingly per shift up and down however that may be. If there ever is a tuner that supplies LP for 04's - 11's the info gathered as far as LP per shift could be beneficial to the 03 guys so they know where they stand as far as LP per shift point, now how they adjust that is another story but there is some great ideas forming in this thread already

 

[RubberFrog]

Kenneth,


There are many factors that could cause transmission failure. If I were running Superchips, with reduced TM, I personally would not run the booster. But that's me. There are plenty that are running the booster without issue. I would rather have a solution that allows the user to tweak line pressures where needed, instead of making a global change. There's no solution like that at the moment, so folks use the resistors and boosters to increase pressure.


Sil

I am running SC with reduced TM and that is exactly why I won't run a sonnax, or any other version.

 

[Redtruck-VA]

Gentlemen, reading the thread becomes interesting and I'm going to be a little critical so bear with me. Has anyone reported a trans failure from too much pressure? I know there have been more than a few from clutch slipping or too little pressure. The OEM design to vary the LP was to reduce parasitic losses (internal drag) from running the LP at a higher pressure then deemed necessary by the engineers. We know the engineers are gods. The trans already operates at 250 lbs. Sharadon did some test which I can't find now operating the trans at 185+ psig for I believe a off road racer. Maybe that article can be found? Or any other articles concerning higher than normal LP operation. What I see is we are all pushing our vehicles by increasing performance and then driving them harder than what is normally recommended which will eventually result in premature mechanical failure. I find it a little strange that folks will modify the engine for maximum output then resist modifying the trans in fear of breaking it. I for one am going to install the adaptor to monitor the line pressure and do what I can to run it high and tight.

 

[Redtruck-VA]

Again this is why I am often reluctant to discuss various subjects because I have a trusty 03. As most know the 03 is the ******* child, however it can easily eleminate torque control and IMO it is a good mod. I have yet seen any 03 go back to the stock configuration after doing this TMR mod. Unlike the newer trucks using the SC tuner where they can adjust the amount of reduction the 03 is all or nothing. I did the TMR mod way back and then installed a 220k ohm resister (Transgo) LP booster only a couple of years ago. This made no noticeable change, but on the other hand it really shouldn't have if the trans was not already slipping and not having a gauge to see what my LP was before and after the resistor install I have no idea how much LP boost I got. The clutches really don't move much when engaged or released. So, if you think they are clunking then you need to check your U joints, because it's not the clutches.

Edit: And don't forget, torque management and Liine pressure are two different things.

 

[Ramunit]

Again this is why I am often reluctant to discuss various subjects because I have a trusty 03. As most know the 03 is the ******* child, however it can easily eleminate torque control and IMO it is a good mod. I have yet seen any 03 go back to the stock configuration after doing this TMR mod. Unlike the newer trucks using the SC tuner where they can adjust the amount of reduction the 03 is all or nothing. I did the TMR mod way back and then installed a 220k ohm resister (Transgo) LP booster only a couple of years ago. This made no noticeable change, but on the other hand it really shouldn't have if the trans was not already slipping and not having a gauge to see what my LP was before and after the resistor install I have no idea how much LP boost I got. The clutches really don't move much when engaged or released. So, if you think they are clunking then you need to check your U joints, because it's not the clutches.

Edit: And don't forget, torque management and Liine pressure are two different things.

I disagree, high line pressure can cause harsh engagement resulting in a "clunk"

 

[SilsHemi]

Edit: And don't forget, torque management and Liine pressure are two different things.

This is correct, but adjusting both together isn't necessarily a good thing. Especially when making a global change to all pressures. Furthermore, the way Superchips adjusts TM for 2004-2010 involves changes on the TCM side as well. Example: Stock pressure for 1-2 in the Hemi is 160 psi. That's already a very high number. 2-3, 3-4, etc. are less. Making incremental adjustments for 1-2 would be a better solution. Adding 30 psi to 1-2, with reduced TM, in my opinion isn't a good thing. That would produce an overly aggressive shift. Adding 30 psi to reverse isn't a good thing either. Adding psi to 2-3 could be a good thing because, the stock psi there is lower. I asked the programmer if he made adjustments to LP for 1-2 in house. Here's his response:

"I have used it in the past. But, with the torque management out of the system it makes the shift real hard- almost too hard. Technically it is better to pin point the gear setting for a higher line pressure over a mass change."

I'm sure some folks would like an almost too hard shift, but if you could tweak it to be just right that would be the optimal. Most of these trucks are daily drivers as well. Track trucks may want this kind of shift. This a a good thread Greg. Thanks for posting it.


Sil

 

[Redtruck-VA]

I disagree, high line pressure can cause harsh engagement resulting in a "clunk"

Scott, I encourage disagreement it brings out points that are otherwised overlooked. I would like to state that a clutch pack being activated at a normal 135 psig (OEM pressure) and a pack that is being hit with 185 psig will respond the same with the only difference being the higher pressure will reduce contact slippage. This will reduce clutch wear and heat. There is really very limited travel within the clutch packs so the clutch itself will not be clunking. Also, most shifting shock is absorbed by the TC. Higher stall TC are softer by design and can absorbs even more of shift shock. I'll give you, your definition and mine may differ for the word clunk. But if your "trans" is making noise shifting or going into gear you probably have other issues.

 

[RubberFrog]

I'm sure some folks would like an almost too hard shift, but if you could tweak it to be just right that would be the optimal. Most of these trucks are daily drivers as well. Track trucks may want this kind of shift.


Sil

This pretty much sums up why we would like user adjustable line pressure.

 

[Redtruck-VA]

Sil, like everything with mods there are a ton of varibles involved and really depends on personal preference. A really harsh shifting trans with a OEM TC might very well feel soft with a high stall converter. So making any general recommendation other than everyone needs 4:56 gears is not the best approach. Good luck with the new trans options....

PS I'll be reflashing my PCM when I get back and hopefully won't have anymore issues with my SC3865. Believe me I will let you know how that goes.

 

[Redtruck-VA]

This pretty much sums up why we would like user adjustable line pressure.

George, Absolutely, to make your adjustments on the tuner to suit indivdual needs would make for a perfect world...

 

[SilsHemi]

Sil, like everything with mods there are a ton of varibles involved and really depends on personal preference.

This is correct and one of the main reasons I believe an LP app that gives the user fine tuning control is the way to go. Good luck with your 3865.


Sil

 

[frostking]

Everyone is barking up the wrong tree. Increased line pressure is what gives more holding power while in a gear and not the predominant factor in shift firmness. I could care less about firmness. I need to hold major low RPM torque. The shift solenoids are pulsed shorter or longer to control how quick a shift is and can be adjusted without messing with line pressure.

 

[RubberFrog]

You cant just shift real quick with the solenoid and expect the clutches to grab each other instantly. Increased line pressures allows a quick shift to actually happen by allowing the clutches to grab. Imagine shifting quickly in a stick, but leaving the clutch slightly depressed for an extra half second.

 

[frostking]

Yes, line pressure plays into it but the slow shifts are from the computer timing the solenoids. Slamming the solenoids at stock line pressure will still be harsh enough to break things without having to increase the pressure.

 

[RubberFrog]

You may be right, when it gets this deep into the trans functioning and programming, I get lost.

 

[Redtruck-VA]

Darell,
Since you recently completed your own trans rebuild I appreciate your input. Running a turbo'd 03 has given you a lot of exposure on how to work around some of the problems that come up taming a 03.

 

[RAMpage]

Ive got an 03 with major tranny problems and a complete overhaul and uprgrade coming in about two weeks minus new cases. i dont remember the exact codes its pullin but it got to the point where it wouldnt shift into forth at all so i lost fifth as a result and then a few days later 3rd started slipping from the word go. its slipped ever since i stabed the throttle with the new motor and just got worse over time. the new trannys gonna have new planitaries and all new internals with an upgraded solinoid, bigger clutch packs, shft kit, molded reverse piston for the increased line pressure, tripple disc stall converter set for the cam specs and a special tranny fluid called raptor blood to increase holding power. ill be sure to give you guys some input on the new tranny. its a 545rfe and its junk with the crysler tuning on it. the company thats building my tranny kit is transmission one and the guy im taliin to there said they are in the process of getting a stand alone unit for these transmissions and the 45 rfes for the 1500 series trucks. the problem with these transmissions is the factory programming. if someone had a stand alone crontol unit for these trannys they would be very hard to beat but chrysler obviously thought we couldnt handle the potential of it so they had to treat us like tards. hopefullly transmission one or someone else will get us a solution to our problems and get a stand alone unit out there sooner than we expect.

 

[Redtruck-VA]

Not sure I read that correctly, sounded like you installed your new motor in front of a trans that you knew was crippled and a now it is getting worse. Well anyway you got a plan for a new one. Let us know how it all works out for you. As you already know there is no transmission support for the 03. As you can see from the thread we are developing some ideas, or at least trying to. It's all fun...

 

[adamwilkes14]

I would like to know who transmissioncenter.net is having blend and package that Raptor Blood...I can't find anything on it as far as specs go that doesnt go to PATC. I would like to have a sample of it and take it to our lab at work and break it down like we did Lucas.

 

[Redtruck-VA]

I have never heard of it before. But I live a sheltered life.....