4L60E 1-2 Accumulator - Pinless Piston Installation - Inner Spring Purpose?

[fivetears]

Having installed a handful of B&M valve body shift kits since the mid 70's, and figuring it's going to take more than a "key punch" activity to get my 4L60E to shift when I want it to... I've looked to Transgo and Sonnax both for mechanical / hydraulic solutions. My question? What's the point of using the second "inside" yellow spring? Once the wider pinless piston bottoms out in the housing, that stronger yellow spring barely contacts the compressed piston. All that spring to absorb .015" of travel after contact at max travel? Just curious if anyone has had a similar observation with the pinless Sonnax part. I can't buy into the distorted flattened yellow spring phenomenon when the OEM piston (by the virtue of its thinner casting) travels much farther into the cylinder than the Sonnax part. In other words... the Sonnax pinless piston skirt bottoms out in the cylinder bore and renders the yellow spring practically useless. Anyone have experience with this issue or have a link to deeper reading? I've pecked this keyboard to death keyword searching for an answer, so I'm trying here.

[TransGo Robert]

Having installed a handful of B&M valve body shift kits since the mid 70's, and figuring it's going to take more than a "key punch" activity to get my 4L60E to shift when I want it to... I've looked to Transgo and Sonnax both for mechanical / hydraulic solutions. My question? What's the point of using the second "inside" yellow spring? Once the wider pinless piston bottoms out in the housing, that stronger yellow spring barely contacts the compressed piston. All that spring to absorb .015" of travel after contact at max travel? Just curious if anyone has had a similar observation with the pinless Sonnax part. I can't buy into the distorted flattened yellow spring phenomenon when the OEM piston (by the virtue of its thinner casting) travels much farther into the cylinder than the Sonnax part. In other words... the Sonnax pinless piston skirt bottoms out in the cylinder bore and renders the yellow spring practically useless. Anyone have experience with this issue or have a link to deeper reading? I've pecked this keyboard to death keyword searching for an answer, so I'm trying here.

None of our kits springs are compatible with those accumulator pistons, if you are using our kit please use OE style accumulator pistons only.

[fivetears]

None of our kits springs are compatible with those accumulator pistons, if you are using our kit please use OE style accumulator pistons only.

Thanx Robert. Completely agree; having tested, measured cylinder travel differences, the pinless pistons (by any manufacturer) do not travel the same distances as the OEM counterparts. Travel in the 1-2 accumulator renders the inner spring <90% functionless. Bought a new pinned OEM GM assembly for the dual spring accumulator; staying with pinless at the remaining while considering mechanical functions/limitations, noting spring rate differences and reviewing the pneudraulic requirements of the kit pieces.

No disrespect intended whatsoever Robert. Transgo products are firm footing in the overhaul and performance arena's. Y'all have solid phone tech support (which I used yesterday) that helped me with the 2017 .PDF change on the current 4L60E HD2 Kit to remove the need to drill one specific hole. Hell, you've been the only person to field a question from me this year. LMAO. Thanks Robert.

Now that I'm a 40-year retired heavy aircraft Pneudrualic Systems Technician, I got all the time and resources to learn this slushbox.

[TransGo Robert]

Thanx Robert. Completely agree; having tested, measured cylinder travel differenced, the pinless pistons (by any manufacturer) do not travel the same distances as the OEM counterparts. Travel in the 1-2 accumulator renders the inner spring <90% functionless. Bought a new pinned OEM GM assembly for the dual spring accumulator; staying with pinless at the remaining while considering mechanical functions/limitations, noting spring rate differences and reviewing the pneudraulic requirements of the kit pieces.

No disrespect intended whatsoever Robert. Transgo products are firm footing in the overhaul and performance arena's. Y'all have solid phone tech support (which I used yesterday) that helped me with the 2017 .PDF change on the current 4L60E HD2 Kit to remove the need to drill one specific hole. Hell, you've been the only person to field a question from me this year. LMAO. Thanks Robert.

Now that I'm a 40-year retired heavy aircraft Pneudrualic Systems Technician, I got all the time and resources to learn this slushbox.

I had to look up Pneudraulics, first time I ever hear that terminology. looks like its mainly a military thing. On the HD2 instructions, you lost me there. I am the one that corrects them when mistakes are found, if there is something that needs to be addressed on there let me know i'll get right on it.

[fivetears]

I had to look up Pneudraulics, first time I ever hear that terminology. looks like its mainly a military thing. On the HD2 instructions, you lost me there. I am the one that corrects them when mistakes are found, if there is something that needs to be addressed on there let me know i'll get right on it.

Pneudraulics - Fuels & Hydraulics. Military origin perhaps. Been a term of my vocabulary since July 1981; USAF Tech School.

Ok Robert, here's the anomaly: On the current 4L60E-HD2 instructions dated 28 Sept 2017; Page 4 - On the top righthand side of the page there's a block of text that reads, "Start Z bolts first...gaskets to case." Look at the word gaskets. Where the letters ke are, focus your eyes down to the second OEM hole; 1.25" straight down on the actual plate. Prior to 28 September 2017, the previous HD2 instructional PDF called for this hole to be drilled to .093

Not being sure of what changed, that rendered this hole diameter to no longer be enlarged to .093, was why I made the call. My new plate has this hole at .0775

Robert, GM has a new manufacturing process for the 4L60E valve body separator plate P/N: 24241783. Both snap on filter screens have been replaced by flat screens embedded into the case-side gasket. Even more, these new GM valve body gaskets are pre-adhered to each side of the new plate. This (I feel) poses new issues with drilling/enlarging fluid passages; namely a foreign object (FO) finding its way in between the layers of this new assembly. Yes sir... the potential exists. See pics. Drill bits tearing the gasket surfaces could be another concern.

So if you find your transmission steel check balls have hammered craters into your separator plate, and you buy a new one... this is what you get and have to deal with; beyond the current Transgo instructions.

[TransGo Robert]

Pneudraulics - Fuels & Hydraulics. Military origin perhaps. Been a term of my vocabulary since July 1981; USAF Tech School.

Ok Robert, here's the anomaly: On the current 4L60E-HD2 instructions dated 28 Sept 2017; Page 4 - On the top righthand side of the page there's a block of text that reads, "Start Z bolts first...gaskets to case." Look at the word gaskets. Where the letters ke are, focus your eyes down to the second OEM hole; 1.25" straight down on the actual plate. Prior to 28 September 2017, the previous HD2 instructional PDF called for this hole to be drilled to .093

Not being sure of what changed, that rendered this hole diameter to no longer be enlarged to .093, was why I made the call. My new plate has this hole at .0775

Robert, GM has a new manufacturing process for the 4L60E valve body separator plate P/N: 24241783. Both snap on filter screens have been replaced by flat screens embedded into the case-side gasket. Even more, these new GM valve body gaskets are pre-adhered to each side of the new plate. This (I feel) poses new issues with drilling/enlarging fluid passages; namely a foreign object (FO) finding its way in between the layers of this new assembly. Yes sir... the potential exists. See pics. Drill bits tearing the gasket surfaces could be another concern.

So if you find your transmission steel check balls have hammered craters into your separator plate, and you buy a new one... this is what you get and have to deal with; beyond the current Transgo instructions.

Regarding that orifice in the plate, in 2016 when we went for 4L60E-HD2-C to the latest 4L60E-HD2-D version of the kit, we changed the 1-2 shift valve to the one with the slug instead of the checkball and spring (change had to be made because the newer solenoid would not flow the same as the old one when off). With the new design valve, there was no longer a need to enlarging that orifice. In fact, it could cause issues with the new valve design. That hole is to orifice manual low oil going to the 1-2 shift valve, and we use that in our special valve to get the Gear Command™ feature to work.

On the newer units with the bonded gaskets it is not a problem to drill the plate as long as the gaskets are still good but if you need to replace the plate, just get ours instead they are regular plate with separate gaskets. https://transgo.com/product-details/...arator-plates/

[fivetears]

The HD2 kit arrived late yesterday. Bought some new check balls too; those rubberized milk dud looking ones.
Thanx again for the education.

[TransGo Robert]

The HD2 kit arrived late yesterday. Bought some new check balls too; those rubberized milk dud looking ones.
Thanx again for the education.

[fivetears]

Got the HD2 kit installed; all sans boost valve and clutch springs; 4L60e not removed to facilitate the complete install. Second accumulator was a pin / aluminum piston kit upgrade. The remaining two received the Sonnax treatment with HD2 kit springs. Installed a Corvette servo and applied all valve body HD2 Kit upgrades including optional step 5.

The test drive got off to a rocky start when the 'vette servo tried to partially exit; failed to insure the retainer ring was completely seated. Installed another 'vette servo and hit the road again. 1-2 shift is akin to a horse kick and immediately got my full attention. 2-3 shift occurred the very split-second I selected it, but no big thrill. Decided to return to the garage and re-evaluate.

Spoke with a tech rep at Transgo and was told there were no requirements to update/tune the PCM to support a Transgo kitted 4L60E.
I continue to harbor minor grief issues with the tuneless installation. Intermittent rain in San Antonio is keeping me in the driveway. Further tests on hold for now.

Any truth to the "tuneless installation" Robert?

[TransGo Robert]

Got the HD2 kit installed; all sans boost valve and clutch springs; 4L60e not removed to facilitate the complete install. Second accumulator was a pin / aluminum piston kit upgrade. The remaining two received the Sonnax treatment with HD2 kit springs. Installed a Corvette servo and applied all valve body HD2 Kit upgrades including optional step 5.

The test drive got off to a rocky start when the 'vette servo tried to partially exit; failed to insure the retainer ring was completely seated. Installed another 'vette servo and hit the road again. 1-2 shift is akin to a horse kick and immediately got my full attention. 2-3 shift occurred the very split-second I selected it, but no big thrill. Decided to return to the garage and re-evaluate.

Spoke with a tech rep at Transgo and was told there were no requirements to update/tune the PCM to support a Transgo kitted 4L60E.
I continue to harbor minor grief issues with the tuneless installation. Intermittent rain in San Antonio is keeping me in the driveway. Further tests on hold for now.

Any truth to the "tuneless installation" Robert?

Correct nothing to tune, the kit is design to work with factory programming.

Why did you not install the boost valve? Is it because yours as an input speed sensor?

[fivetears]

No Robert, just heeded the note: on page 5: "If Trans is on Bench, remove Pump and install Step 1 PR parts." My speed sensor is on the transfer case; 4X4. Also watched a UTV showing an "in-Vehicle" struggle with it and elected to forego the installation for now. I figured it would also be best to see what all the other upgrades did before I jacked up the pressure to the Transgo standard. I think I need a narrower set of snap ring pliers too. Having Dextron in my eyes and nearly every other orifice of my face over a two-day time frame and ruining a pair of Chuck Taylors from putting a foot in my drain pan... yeah, patience wore too thin.

So I'll take it that since this kit is "design to work with factory programming" any code I get is going to be from something I did (or didn't) do. No codes to date. I am put back a notch trying to accept this computerized marvel accepts all the Transgo changes without a blip of concern. Search me.

[TransGo Robert]

No Robert, just heeded the note: on page 5: "If Trans is on Bench, remove Pump and install Step 1 PR parts." My speed sensor is on the transfer case; 4X4. Also watched a UTV showing an "in-Vehicle" struggle with it and elected to forego the installation for now. I figured it would also be best to see what all the other upgrades did before I jacked up the pressure to the Transgo standard. I think I need a narrower set of snap ring pliers too. Having Dextron in my eyes and nearly every other orifice of my face over a two-day time frame and ruining a pair of Chuck Taylors from putting a foot in my drain pan... yeah, patience wore too thin.

So I'll take it that since this kit is "design to work with factory programming" any code I get is going to be from something I did (or didn't) do. No codes to date. I am put back a notch trying to accept this computerized marvel accepts all the Transgo changes without a blip of concern. Search me.

You really should do the PR spring and the boost valve, otherwise the kit does very little, not to mention that all the other calibration now are not correct since main line is not where it should be for those calibration. Yea ATF down the armpits and in your eyes is not fun, but in this case it is really not something you want to skip. As for the computer, it has very little control on the transmission, it is not like modern clutch to clutch synchronized transmissions. On a 4L60E the only things the computer controls is the shift timing by deciding when it is firing the shift solenoids and the kit does not change any of that except for the protection from back to low where we override the computer when you do the optional step 5 on page 2. Other then that the computer control the line rise, we simply give it a little more base line and a steeper rate of boost. The computer has no feedback for line so it never notices a problem, everyone is happy.

[fivetears]

Hope you and family had a wonderful Easter Robert. The 4L60E and Transgo HD2 systems relationship & operational explanation you provided (below) was perfect; clear & concise.

As for the computer, it has very little control on the transmission, it is not like modern clutch to clutch synchronized transmissions. On a 4L60E the only things the computer controls is the shift timing by deciding when it is firing the shift solenoids and the kit does not change any of that except for the protection from back to low where we override the computer when you do the optional step 5 on page 2. Other then that the computer control the line rise, we simply give it a little more base line and a steeper rate of boost. The computer has no feedback for line so it never notices a problem, everyone is happy.

I took your recommendation (below) to heart over the weekend and ordered a pair of 90 degree offset extended tip snap ring pliers and a new fluid catch receptacle to make it happen.

You really should do the PR spring and the boost valve, otherwise the kit does very little, not to mention that all the other calibration now are not correct since main line is not where it should be for those calibration. Yea ATF down the armpits and in your eyes is not fun, but in this case it is really not something you want to skip.

Gonna pull the pan back off and follow through. Bet that VB has to split again too. if so... so be it. My bad.

[fivetears]

The Pressure spring and Boost valve upgrade was very easy; well... keeping the regulator valve up in the pump stator was a bit frustrating, but all in all; very easy. I removed the manual shift valve detent spring and rotated the gear selector as necessary for tool clearance. Didn't require VB removal either. Makes a notable difference in shift quality across the board. Thanks again Robert.

[TransGo Robert]

The Pressure spring and Boost valve upgrade was very easy; well... keeping the regulator valve up in the pump stator was a bit frustrating, but all in all; very easy. I removed the manual shift valve detent spring and rotated the gear selector as necessary for tool clearance. Didn't require VB removal either. Makes a notable difference in shift quality across the board. Thanks again Robert.

Good job