Torque reduction

retmil46 · **Posted:** Tue Oct 09, 2007 3:20 pm

MrWinkey wrote:

Yes but what if you send your tranny to Ron to upgrade the clutch packs and such?

This is my current plan....remove the tranny and have it rebuilt after the 70k warranty is up.

He did mention that if someone were determined to go this route, that they should install heavy duty clutch packs. Wasn't clear if he would endorse it even then.

For most people, that just want the tranny to hold together and work reliably for normal driving, that's a lot of expense to go to for what has been reported to be seemingly very little gain.

MrWinkey · **Joined:** Tue Apr 18, 2006 3:16 pm **Posts:** 37

Well that is why I'm going to wait for this TC to vomit before I deal with it.

But if I'm pulling the tranny I might as well upgrade to the heavy duty TC and cluch packs.

No point in pulling everything only throw junk back in.

gmctd · **Posted:** Wed Oct 10, 2007 12:18 pm

The Hemi trucks need the extra strength and friction on the track - you can specify the Red Eagle or the BW clutches anytime you have the trans rebuilt - they are standard options in the trans industry

BankNote4X4 · **Posted:** Wed Oct 10, 2007 9:25 pm

As far as Transgo shift kits, Ron's advice was not to install the resistor mod on the control harness if you purchased the kit that includes it. He said the replacement springs did a more than adequate job of maintaining line pressure, and if I understood Ranger1 correctly, the resistor has basically the same effect as disconnecting the torque reduction request wire.[/quote]

Do the Transgo Kits from SunCoast contain a Resistor Mod?
Can I assume my tranny shop would have installed the resistor mod?
Can I remove this easily?

danoid · **Posted:** Wed Oct 10, 2007 9:27 pm

Please plug the pin back in.

Shift torque reduction is an important component of transmission durability.

What happens when you upshift from 1st gear to 2nd gear? Speeds change. How does this happen? Clutch actuation. What speed changes? The engine, not the transmission output (the tires). Is it easier to lower engine rpm if the engine is making more torque?

Put it another way. When you shift a manual transmission do you let off the accelerator or keep it down? How long do you expect a manual transmission to last if you keep on the gas while shifting? Why do you expect an automatic to last while doing the same thing?

danoid · **Posted:** Wed Oct 10, 2007 9:33 pm

BankNote4X4 wrote:

As far as Transgo shift kits, Ron's advice was not to install the resistor mod on the control harness if you purchased the kit that includes it. He said the replacement springs did a more than adequate job of maintaining line pressure, and if I understood Ranger1 correctly, the resistor has basically the same effect as disconnecting the torque reduction request wire.

Maintaining line pressure is wasting energy (fuel). Line pressure is maintained by a pump that is driven by engine torque. Lower pressure means less engine torque required to drive the transmission. Variable line pressure was introduced to save fuel. Installing a shift kit to defeat that feature is not a help.

HERE IT COMES! Now everyone can jump on that bandwagon and yell at me about once again saying that shift kits are snake oil...

ATXKJ · **Posted:** Wed Oct 10, 2007 9:43 pm

danoid

if I remember the original post - you said the adaptive feature of the transmission would learn the changes from the shift kit and adjust for them - you're now saying it won't adjust and that the increased line pressure will waste fuel.
So either it will adjust and the shift kit will have no value - or it won't adjust and it'll waste fuel (but have a higher line pressure)-

your choice but you can't have both.

FYI - mine hasn't adjusted in the last 6,000 miles and it gets better mileage.

FYI 2 - I also called Ron about the resistor - he said the main problem they saw was in a Hemi application where there was a TCM update (obviously not the 545) and the resistor - increased to too high a line pressure and burned out the pump - he didn't think it would be that much of an issue on the CRD since we can't update the TCM - however I may pull a resistor if I add a tuner chip.

danoid · **Posted:** Wed Oct 10, 2007 10:02 pm

The clutch fill times (shift quality) will adjust to preset rpm accelerations. Line pressure goes to max during a shift anyways. Variable line pressure tries to lower the pressure (energy) while the transmission is in gear, not shifting. Thus, while cruising down the road with 10 psi (or whatever the shift kit is doing) too much pressure, you're thowing fuel out the door.

Every vehicle gets better fuel economy as it ages, until the rings wear out and blowby overcomes the positive effect of break-in.

gmctd · **Posted:** Wed Oct 10, 2007 10:44 pm

The Hemi's run the 545 also, prolly with the identical t\c - you should not manually increase line pressure if the 'tune' also raises it - alternately, you could wire-in a variable resistor, rather than the fixed version, or a switched resistor, for experimentation with the tune

One thing the resistor does is provide increased pressure while the t\c is engaging or disengaging, to get better apply-piston action - that is the precise time TCM is doing that emc2 stuff, trying to take it easy on the TCC lining - that's the 'shudder' felt at lockup and downshift - doesn't even help that the TC is sloppy - kicking line-pressure up should help at that point, if the TCC is up to the challenge - hopefully the intelligent euro-tune setup should compensate for it

The shift kit contains, amongst other goodies, several items intended for hi-mileage transmissions - some springs and other doodads for the pump, which, because they're laid horizontal instead of vertical, wear considerably as mileage accrues - you guys with low-mileage way under 100k trans need not worry about that stuff.

The 545 has been around since the turn of the century, in one form or another, so some are gettin' mighty long in the tooth, here at the end of ought seven - not your problem - ours just had a new TCC and pump MAR07.

The 5 servo accumulators get improved seal-rings and springs with altered tension, intended to increase shift response while reducing leakage, which increases pressure stability - should help keep the TCM sane.

Now, if you can also reduce fluid temperature while you're cheerfully romping thru the woods, or otherwise flogging it unmercifully, TCM should respond with reliable control in any situation.

chrispitude · **Posted:** Thu Oct 11, 2007 8:37 am

Since we're on the topic, I have a question about shifting.

While towing my trailer (5000lbs), I let off the throttle briefly when the transmission makes the shift from 4th to 5th. My thinking was that it was better to not transmit power while the transmission was in the process of re-locking in 5th. Is this unnecesary, and the transmission does the proper things internally to prevent unnecessary wear if I keep my right foot where it was?

- Chris

gmctd · **Posted:** Thu Oct 11, 2007 9:18 am

Normally, it is unnecessary - if the trans s-s-l-l-i-i-i-i-ps into gear, then you could consider helping it a little - how was the overall shifting and TCC lockup after the Suncoast upgrade?

retmil46 · **Posted:** Thu Oct 11, 2007 10:45 am

BankNote4X4 wrote:

Do the Transgo Kits from SunCoast contain a Resistor Mod?
Can I assume my tranny shop would have installed the resistor mod?
Can I remove this easily?

They sell two different versions of the shift kit, one with and one without the resistor.

From what I gathered from Ranger1, the version Suncoast sells DOES NOT contain the resistor, for reasons already mentioned in this thread.

Don't assume anything, ask them!!

Don't know if it is easily removeable or not, I'm not familiar with the way it's installed.

ATXKJ · **Posted:** Thu Oct 11, 2007 11:24 am

The Suncoast Transgo kit - includes the resistor mod
(I just gave mine to the transmission shop and said install -so they added it)
- instructions show it on a connector outside the transmission - bridges 2 wires - should be fairly simple to unsolder.

http://liberty.eurekaboy.com/545rfeinstructions.pdf
scroll down to page 4

gmctd · **Posted:** Thu Oct 11, 2007 12:59 pm

You can clip one wire to disconnect the resistor for later experimentation, or both to remove it - the Transgo 545RFE-HD2 Reprogramming Kit has the resistor, the SK-45RFE kit does not - I think the SK is not carried by Suncoast

CATCRD · **Posted:** Fri Oct 12, 2007 3:26 pm

I got the HD2 kit, not from suncoast, and the line pressure resistor made the shifts act weird, and inconsistent. I took it out and I'm much happier with it.

gmctd · **Posted:** Fri Oct 12, 2007 4:19 pm

Just thought I should mention, here - my posts are not intended as contradiction of Danoid and others' input - only to give a general idea of what the shift kit is designed to do, and the transmission's expected response.

As indicated, if the TCM is intelligent, programmed shift-event duration - the time it takes to upshift from 1st to 2nd, 4th to 5th, even TCC lockup - is monitored by comparing input shaft speed to output shaft speed - slippage will increase event duration, and TCM should respond with more pressure as needed to expedite the event - if duration is short, TCM should respond by decreasing pressure

A shift kit functions mechanically and hydraulically to decrease shift duration, making for quick, firm shifts - TCM may not respond well to that interference

It will be easier to determine TCM response as more owners post on the results in their vehicle - so far, the upgrade seems to be a satisfactory improvement

ATXKJ · **Posted:** Fri Oct 12, 2007 9:00 pm

On the CRD side most of the folks installing shift kits have done it in conjunction with the Suncoast so the results are confounded.
On the gasser side - there have been some shift kit installs seperately - reporting positive results.

Mine works better - but I added the Suncoast at the same time so I can't distinguish between torque converter and shift kit except by subjective feel, which is a really bad measurement technique.

BankNote4X4 · **Posted:** Sun Oct 14, 2007 5:49 pm

Pulled the plug, unwrapped the electrical tape, and sho nuf, transistor. Cut both wires re-wrapped, and so long random hard jerking shifts. Ah

finally drives right. Thanks again.

chrispitude · **Posted:** Sun Oct 14, 2007 7:52 pm

I had a shop do my install. Which connector would have the resistor?

- Chris

ATXKJ · **Posted:** Sun Oct 14, 2007 8:11 pm

The passenger side of the transmission - there's a plug - the resisitor was soldered bridging 2 of the lines.
(on the plug don't forget - pull back on the red to unlock and press the center to release - similiar to other plugs like the MAF)

I just took mine out today - the shifts are a lot smoother. With the resistor - the 1-2 shift while the trans was cold - felt almost like a manual powershift without the clutch.

Torque reduction

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