Tranmission upgrades

gmctd · **Posted:** Thu Dec 04, 2014 5:57 pm

dirtmover wrote:

gmctd wrote:

- loss of battery voltage dumps the memory

So, if you disconnected the battery, the TCM went dumb and don' kno' nuttin 'bout nuttin..........

You sure about this? I've read it in many places but I've had the battery disconnected many times for as much as many days at a time and never noticed any changes in the performance so I suspected that disconnecting the battery simply causes the owner to forget how his vehicle drives. Kinda like a placebo effect.

You'd probably notice it if your driving course had sudden changes in it - like a short trip thru traffic, then right onto the service road, then onto the hiway - you'd likely notice it more when back down into street traffic and down-shifting, then normal upshifting\down-shifting in slower traffic till your arrival and parking

Cold weather would amplify the effect, where fluid temps slowly increased to operating levels

It's just a capacitor that holds the internal voltage - how fast it bleeds off determines the state of the memory - age and cold effects faster bleed-off

gmctd · **Posted:** Thu Dec 04, 2014 6:07 pm

WWDiesel wrote:

gmctd wrote:

my personal delivery style, like no other, eh.........

Took a bit of getting used to, but now I understand and pay your comments no attention!!!! A SA!!!
SA=Strong Attitude! :ROTFL:

Inference noted and accepted - since that part of my body was also present at each and every learning juncture, it must therefore be assumed that it is also, by association, smart, eh............

dirtmover · **Posted:** Thu Dec 04, 2014 10:45 pm

gmctd wrote:

dirtmover wrote:

gmctd wrote:

- loss of battery voltage dumps the memory

So, if you disconnected the battery, the TCM went dumb and don' kno' nuttin 'bout nuttin..........

You sure about this? I've read it in many places but I've had the battery disconnected many times for as much as many days at a time and never noticed any changes in the performance so I suspected that disconnecting the battery simply causes the owner to forget how his vehicle drives. Kinda like a placebo effect.

You'd probably notice it if your driving course had sudden changes in it - like a short trip thru traffic, then right onto the service road, then onto the hiway - you'd likely notice it more when back down into street traffic and down-shifting, then normal upshifting\down-shifting in slower traffic till your arrival and parking

Cold weather would amplify the effect, where fluid temps slowly increased to operating levels

It's just a capacitor that holds the internal voltage - how fast it bleeds off determines the state of the memory - age and cold effects faster bleed-off

The thing is that the adaptation is also accounting for wear in the transmission, thinner clutch plates etc. not just subtle differences in driving style. If removing power resets this history and it thinks it's controlling a brand new transmission again then it's going to drive pretty crappy until it re-adapts.

ArmyChief · **Posted:** Thu Dec 04, 2014 11:34 pm

GDE published the spring tensions and torque limits for OE, euro TC and Suncoast. Do we know what the tolerances are for the Hemi TC?

gmctd · **Posted:** Fri Dec 05, 2014 2:40 am

dirtmover wrote:

The thing is that the adaptation is also accounting for wear in the transmission, thinner clutch plates etc. Correct - by monitoring input rpm and output rpm during shift intervals and comparing this to design spec, pressure and valve solenoid timing can be altered to increase apply, compensating for clutch-plate wear and maintaining correct shift-timing interval - 'nuther words, it still gets into each gear on-time - and it's not like worn clutches need timing for 1/2" of increased travel -
not just subtle differences in driving style.
If removing power resets this history and it thinks it's controlling a brand new transmission again then it's going to drive pretty crappy until it re-adapts. It's been a long while since switching back and forth between Hemi and KJ TCMs, so I don't remember particulars, but it seems like there were a few conigulations with each -all I'm can say at this time is: some is as do, some is as don't

ArmyChief · **Posted:** Fri Dec 05, 2014 8:26 pm

Do we have a HP/Torque spec for the Hemi converter?

gmctd · **Posted:** Fri Dec 05, 2014 8:40 pm

ArmyChief wrote:

Do we have a HP/Torque spec for the Hemi converter?

It's here somewhere, likely sometime after ought 7 when I posted the orig information

ArmyChief · **Posted:** Mon Dec 08, 2014 9:56 pm

gmctd wrote:

Again, this is in no way, shape, or scope intended to detract from the aftermarket race-hardened 5.7L Hemi torque convertors - they are simply
not needed to upgrade a KJ driven in normal street or off-road manner - however, they do give excellent bragging rights for those that can
afford them, and those who are also afflicted with the 'mine's bigger'n yours' syndrome

NOTE: I installed the SUNCOAST TC in my KJ B4 anyone knew the oem stock 5.7L hemi TC was the correct and available upgrade - subsequently doing considerable research to determine this, I immediately posted the new information on this forum back in ought 7 - so........

This is for members, and especially new members, who need to know that they do not need to spend a small fortune just to improve seat-of-the-pants-noticeable driveability of the KJ CRD

What is needed is the aggressive forward-curved turbine vane-angles designed into the oem Hemi version which produce much greater hydraulic coupling than the
slightly rear-curved vanes in the KJ - the aftermarket vendors do not alter the Hemi turbine-vane angles - they merely furnace-braze the ends
which are oem inserted into slots with bent-over tips to secure them in-place - brazing is required for hi-performance useage

These pics illustrate the SUNCOAST Hemi TC compared to the stock KJ TC - Suncoast in gray, KJ in rust
viewtopic.php?p=255007#p255007
These pics illustrate the oem stock Hemi TC compared to the stock KJ TC
viewtopic.php?p=547899#p547899

A sense of the difference in thrust can be experienced by sticking an arm out of the window at ~60mph, palm forward, fingers straight - this
represents the hydraulic coupling produced by the KJ TC straight turbine vanes - note the exertion required to keep the arm\hand in place

Now arch the fingers such that the tips are parallel to the heel of the palm, forming a cup - this represents the increased hydraulic coupling
of the curved turbine vanes - note again the exertion required to keep the arm\hand in place

Notice the strong difference in applied force in the two examples

The actual seat-of-the-pants experience is equally noticeble after installing the Hemi TC, with it's drastically-increased hydraulic hookup

The verbiage accompanying these same pics indicates the improved response resulted by installing the factory-stock oem Hemi TC (for those who only look at the pictures and wonder what's it all about)
viewtopic.php?p=547899#p547899

Further word to the wise - any used TC of unknown origin, if not previously flushed by the vendor, should always be flushed prior to installation

Edited lo, these many times, for clarity and syntax

So, do we have a comparison of the OE, Euro TC and Hemi TC? I may be installing a TC in the near future and wanted to know if the Hemi TC is a better option than the Euro TC?

Does it have a higher torque holding value than Euro TC?

If and when I upgrade my TC, I will want to upgrade my tune from Eco to Eco FT or even Hot Tune

gmctd · **Posted:** Mon Dec 08, 2014 11:27 pm

Nothing on the EURO, which is merely a (same as the KJ CRD) 3.7L V6 TC with increased TC Clutch hub spring tension to absorb the greater torque of the 2.8 CRD - no difference in stall speed, which would require aggressive re-curvature of the drive and driven turbine vane-angles

It's not the torque input rating you need concern yourself with - the DCJ 5.7L Hemi V8 is a much more powerful engine than the 2.8L CRD - SUNCOAST, et al, merely "race-hardens" the TC for much greater-than stock Hemi power ratings :
- machines a new 'billet' drive housing\clutch plate to handle upgraded power ratings for drag-racing
- bonds KEVLAR clutch friction material to the clutch-hub\disc for same purpose
- furnace-brazes the drive and driven turbine blades to their respective housings for same purpose
- some other proprietary stuff for same purpose

If you plan on running the li'l puffer in repeated full-power 500hp^ runs at up to 8000rpm down the drag-strip, then the $700^ TC's are what you will be needing

Otherwise, the oem stock across-the-counter Hemi TC will give you the same increased hydraulic hook-up as the $700 version, with the same torque-multiplication ratio, and with even lower stall speed than when used behind the 5.7L V8 Hemi because the 2.8L torque output is lower than the 5.7L Hemi V8 - higher torque = higher stall

The Hemi torque-output is much greater than the 2.8L output across the rpm-band - the Hemi TC is rated to exceed the higher specs of the 5.7L V8

Stall-speed is the highest-rpm any engine can spin a torque-converter with rear brakes locked - using the same TC on two different-power engines, the low-power (torque, HP) engine will "stall" at lower rpm than the hi-power (torque, HP) engine - the term "stall-speed" is then very relative to applied power

The stator, which produces torque-multiplication, is instrumental in stall-speed rpm, but since our concern is with the Hemi TC, hardened and un-hardened, torque-multiplication is the same\similar and need not be of concern in selection choice

Likely, the DODGE RAM HEMI forums will have specific 5.8L TC specs

ArmyChief · **Posted:** Tue Dec 09, 2014 9:09 am

Thanks as always

Franko · **Posted:** Thu Dec 11, 2014 12:11 am

Do we have a part number for the Hemi TC?

gmctd · **Posted:** Thu Dec 11, 2014 2:26 am

Franko wrote:

Do we have a part number for the Hemi TC?

Number(s) is posted in several responses on pg1 of this thread - only one part # for US and Export - there is no EURO version, TMK

ArmyChief · **Posted:** Thu Dec 11, 2014 8:24 am

Franko wrote:

Do we have a part number for the Hemi TC?

5.7L Hemi TC -- 4736587AC
R4736587AD. (remanned) Replaces:4736587AA, 4736587AB, 4736587AC, R4736587AC
new transmission pump - 68009879AB
flat transmission filter - 5013470AD
spin-on transmission filter - 5179267AC
WIX transmission filter set with pan gasket - 58843

Tranmission upgrades

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