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I see that the Transgo 4L60E HD2 kit calls for the use of a blue spring and an orange spring in the 1-2 accumulator on either side of an aluminum piston, and that this is a popular configuration along with no shims used when browsing in the various build threads. I see that from GM, there was at least 3 different spring/piston configurations available which is interesting. The image below is based on various diagrams that I saw in a thread on here. I made this image to simplify the offerings that I viewed from the various diagrams, but not sure if the source images had the configurations correct or not and if this is representative of actual, untouched cores?
I also see that the Trangso 4L60E SK kit doesn't contain the blue spring, only the orange one and that it also contains an inner white spring, a small inner white spring, a small inner red spring, and a small inner orange spring, which get used in a certain 3 spring configurations depending on which piston (type 1, 2, 3) is used. The HD2 kit however only contains the orange and blue spring, and a single configuration recommended in the instructions regardless of which piston type is used.
So my question is this... has anyone come across spring rates or dimensions for the various OEM springs and shift kit springs available?
A reply of "get up off your ***, buy some OEM springs, and start measuring spring rates and dimensions!" is perfectly fine lol. I was just wondering if the information has already been published somewhere.
From my reading, there's quite a few things that go into determining the shift characteristics of the 1-2 shift other than the spring selection and how they are oriented with the piston. For guys that don't purchase the HD2 kit and use different springs with an aluminum piston (or with a pinless accumulator) to achieve the same desired 1-2 shift characteristics that the Blue/Piston/Orange sandwich configuration with no shims provides (along with other modifications aside from spring selection) it's well understood that they know exactly what 1-2 shift sleeve, what oz spring in the 1-2 accumulator bore in the VB to use, what size to drill the separator plate, etc based on the application details and other modifications performed to the unit along with years of trialing and testing...but if there is a spring offered by OEM that is similar to the blue transgo spring, it would be interesting to know what it is. I heard that the transgo orange spring in the 1-2 is prone to breaking, but not sure if that is still the case?
A quick view of a parts manual shows that there's a ton of different colored OEM springs (both inner and outer) in addition to all the other springs that come in a TG SK kit. I'm sure there's more than what's listed here. Combine all this with the all the different coded 1-2 accumulator sleeves and the 5 Transgo springs ranging from 24-88oz that go in the VB, and I see we have quite the number of combinations possible for fine tuning the shift characteristics along with modification of the separator plate.
I haven't come across a reference showing which colored OEM springs under the 1-2 accumulator housing come in which year models and makes, but that would be interesting to see as well if it exists.
Again, not asking for anyone to share their personal data that isn't already out there on test data with various spring rates, only asking if such data already exists somewhere online and if so, can a link be provided to the data.
I have often asked this question of myself.....how many diff springs are available and what are the diff rates among the springs ...that info would greatly assist in choosing a spring rate to soften or stiffen a 1-2 shift....not a fan of the trans go spring setup...and found the 1-2 springs in the sonnax kit to stiff.....i have settled on a spring combo I really like but wonder if there is room for improvement
do you use it by itself or with a inner spring ? what sep plate hole size do you prefer for it ?
Single spring with pinless piston on top. Plate hole size will depend on servo piston and torque converter. I usually don't go over .093 with the 093 piston, most of the time smaller.
I change the Orientation depending on the Application.
Please use either: "Piston against the Separator-Plate", "Spring against the Separator-Plate", "Piston against the Housing" or "Spring against the Housing"...
as the description of said Orientation.
"Piston on top" can be misunderstood.
Those of you who are familiar with the Older Cores and the THM700-R4 Cores...
Know that originally all Units came with the Spring against the Separator-Plate.
With a Firm 1-2 Up-Shift/ Firm 1-2 Accumulator Spring...
The "Spring against the Separator-Plate" Orientation was fine in terms of Parts lasting (particularly the 1-2 Accumulator Spring).
With a Soft 1-2 Up-Shift/ Soft 1-2 Accumulator Spring (just how Grandma liked here Buick, Oldsmobile, or Cadillac)...
This same Orientation most often would result in a BROKEN 1-2 Accumulator Spring.
GMs Solution...?
Flip the Orientation of the 1-2 Accumulator Piston and Spring.
Now a Firm Spring can be used (the Springs that do not break) and have a Soft 1-2 Up-Shift.
The Accumulator Valve-Train was also changed after the Orientation change (R and YZ Letter-Code Accumulator Valve-Train).
i know with 2 spring setups the smaller inner is STIFF as hell.....is there enough oil pressure to actually compress that spring or does it serve as a limiter limiting the stroke of the piston ....does piston stroke matter ???
The function of any accumulator is quite simple. It continually gets covered here and on other forums which is interesting to me.
The bulk of the matter is:
The FASTER an accumulator strokes, the softer the shift will be
The SLOWER an accumulator strokes, the firmer the shift will be
LARGER accumulator oil volume=softer shift
SMALLER accumulator oil volume=firmer shift
So...keeping this in mind.
You can intuitively understand how any change to the accumulator will affect the shift.
More regulated accumulator oil pressure (usually shown in drawings as green oil by GM) will result in a firmer shift. WHY? Because it is the force the accumulator piston must act against. Higher pressure means slower stroke.
The same goes for a spring. If the spring opposes the piston stroke...a firmer spring will make a firmer shift.
If the spring assists the piston stroke...a firmer spring will make a SOFTER shift.
you can even get into the weeds and look at accumulator oil (green) flow volume and why check ***** are used for exhaust on some of those circuits in different units.
This is another reason we pay close attention to band clearance on the 4l60e. It's not just for the timing of the band itself. much of it has to do with oil volume because the servo acts as an accumulator.
changing the clearance of the band, affects the total oil volume needed to move the servo back to the release position.
Now...think about a setscrew when we block accumulators.
Minimal oil volume. And the piston will take an infinite amount of time to stroke...therefore you get the firmest shift possible.
Spring rates and colors and "by the book" configuration is nice and all...but if you don't have the root understanding of how the system all works together, you're still off in left field.
You can mix and match springs, accumulators valves, orifice sizing, clearances, and line pressure. combine that with differences in vehicle weight, converter, rear gear, NVH, etc and you'll get different "feel" no matter what.
Knowing how to adjust that feel once you get it in each particular scenario is key.
02-21-2023, 09:47 PM
1-2 Accumulator Housing Springs? 
