The Ultimate 4L60E 3/4 Clutch ?
10-06-2016 | 12:43 AM
#41
...Your comment about the too-small apply piston makes me wonder why the Transgo HD2 kit has such stiff springs for the 22-spring 3/4 clutch return cage. I estimate they triple the cage return force from 30 lbs to 100 lbs. That is then 70 lbs less apply force on the 3/4 clutch which you indicate needs as much as possible...
Last edited by coryforsenate; 10-06-2016 at 01:11 AM.
10-07-2016 | 12:10 PM
#42
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It would lead me to believe that the stiffer springs would soak up less of the apply before they moved. A soft spring is going to have a lot of travel before it finally becomes stiff enough to actually engage clutches whereas stiff springs will have very little travel before apply. Thus eliminating some of that very short "slip" time GM engineered in for smooth comfortable shifts.
12-26-2016 | 01:55 PM
#44
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Thank you for the additional info Jake.
Q2 - I like to use the 3-4 release springs on the side, which Sonnax recommends and provides for their drum. (It seems logical that they would reduce friction in 1st/2nd gear by keeping the apply and backing plates separated.)
How many of the stiffer Transgo springs should I then use in the 3-4 spring cage? I'm inclined to use 11 of the stock ones and 11 of the Transgo stiff ones. Does anyone have experience and/or recommendations?
By my measurements, using all 22 Transgo stiff springs triples the spring cage pressure from 30 lbs to 100 lbs, resulting in 70lbs less apply pressure on the clutch. (And using 22 Transgo spring and the 3-4 release springs would be too much.)
Q2 - I like to use the 3-4 release springs on the side, which Sonnax recommends and provides for their drum. (It seems logical that they would reduce friction in 1st/2nd gear by keeping the apply and backing plates separated.)
How many of the stiffer Transgo springs should I then use in the 3-4 spring cage? I'm inclined to use 11 of the stock ones and 11 of the Transgo stiff ones. Does anyone have experience and/or recommendations?
By my measurements, using all 22 Transgo stiff springs triples the spring cage pressure from 30 lbs to 100 lbs, resulting in 70lbs less apply pressure on the clutch. (And using 22 Transgo spring and the 3-4 release springs would be too much.)
This trans is in a 500 hp super charged truck, that is street driven for fun.
Thanks
12-26-2016 | 07:41 PM
#45
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Once you install the TransGo springs (install all of them), you do not need or want the other springs, as this will be "too much" (overkill) and will take even more pressure to bring on the 3-4 clutches. The TransGo spring setup is good for 8,000 rpm. If you go over that, then add a .030" bleed hole to the outside edge of the aluminum drum under the 3-4 piston to prevent centrifuge bringing on the 3-4 clutch at high rpm in the top of 1st & 2nd gear.
01-03-2017 | 11:14 PM
#47
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I estimate that the 3/4 piston can exert about 850 lbs on pressure on the 3/4 clutch. Since even the five special "load release" springs on the Smart Drum compress with about 5 lbs each, you are only losing about 25 lbs of pressure, about 5%. It is unlikely to make a noticeable difference.
It would be more important to put a pressure gauge on the trans and make sure you are getting 220-240 psi at full throttle.
It would be more important to put a pressure gauge on the trans and make sure you are getting 220-240 psi at full throttle.
01-04-2017 | 12:09 AM
#48
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Thanks for the info, I hadn't taken the time to figure pressure based on area. I have a pressure gauge permanently mounted in the cab. Before I tore the trans back apart I was getting 190 psi at 8400' elevation. Could be up to 255-260 with pressure correction, but I was only around 240 psi at sea level. Little figuring left to do on that part.
I put the truck back asleep for the rest of the winter, mostly wanted to get the trans project out of the garage. Success it moves in all gears
The truck had been sitting for 8 months and I was out of methanol for injection, so I did not get on the truck to test it out. have to wait for warmer days.
I put the truck back asleep for the rest of the winter, mostly wanted to get the trans project out of the garage. Success it moves in all gears
The truck had been sitting for 8 months and I was out of methanol for injection, so I did not get on the truck to test it out. have to wait for warmer days.
01-04-2017 | 10:05 AM
#49
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First, I don't see why hydraulic pressure would go down with altitude.
Second, even if it does, you are only 4 psi lower at 8400'.
190 psi is low for a performance transmission. You may want to install the Sonnax .490 boost valve which has o-rings to seal a worn bore.
BTW - Some pressures, like tire pressure, actually goes up with altitude because there is less atmospheric pressure to counteract the pressure source.
Second, even if it does, you are only 4 psi lower at 8400'.
190 psi is low for a performance transmission. You may want to install the Sonnax .490 boost valve which has o-rings to seal a worn bore.
BTW - Some pressures, like tire pressure, actually goes up with altitude because there is less atmospheric pressure to counteract the pressure source.
01-10-2017 | 06:51 AM
#50
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Thanks, I allowed my self to get confused with the altitude pressure calcs. I knew the pressure it self did not change, but was trying to calc for less on gage. Finally found some of my old hydraulic books and it would drop 4 psi on the gauge. I had the Transgo boost valve in the trans. Now I have a new pump with Sonnax o-ring boost valve and a new Sonnax complete valve body so hopefully will be good now. I will make sure it is up around 240 psi this spring when I get it back out.
One last quick question does anyone know of or have recommendations for someone who is good at tuning a 94 4l60E with TunerPro in a pretty modified truck engine and trans?
One last quick question does anyone know of or have recommendations for someone who is good at tuning a 94 4l60E with TunerPro in a pretty modified truck engine and trans?
04-03-2018 | 12:57 PM
#53
What year is it? Some improvements were made for ones produced after certain years.
And yes, a good rebuilt 4l60e should have addressed the 3-4 clutch issue to varying degrees depending on what your budget is.
And yes, a good rebuilt 4l60e should have addressed the 3-4 clutch issue to varying degrees depending on what your budget is.
04-04-2018 | 06:41 AM
#54
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In 1994 GM introduced the 1st generation 3-4 Borg Warner Hi-Energy clutches, and in 1996 the Borg Warner Hi-Energy 2nd generation clutches started being used, which were used to the end. This solved which material would be the best to use in the 3-4 clutch pack. GM added the .472" boost valve in the High Performance units, the Corvette servo was also being used. This combination helped a lot. In 2002 the 7 clutch (instead of 6) BW Hi-E 3-4 setup was introduced, and this helped even more. I had pretty much solved the 3-4 clutch problem back in the 1995/1996 time frame, when they introduced the BW Hi-E's. All of my rebuild kits come with the 3-4 setup, larger boost valve, matching servo, etc. matched to what you have, what the vehicle is for, how much horsepower and how you drive. So yes, my kits address the 3-4 clutch problems.
04-06-2018 | 07:05 PM
#56
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A cheapo rebuild will probably use only 6 cheap frictions in the 3/4 clutch; not even as good as the OEM ones. Probably true for many aftermarket "swaps".
If you have a local shop rebuild it, be sure they use 7 BW HE frictions as PBA explained.
Lots of builders say the GPZ frictions are equal to the BW HE; so either of those.
If you have a local shop rebuild it, be sure they use 7 BW HE frictions as PBA explained.
Lots of builders say the GPZ frictions are equal to the BW HE; so either of those.
04-07-2018 | 02:25 PM
#57
Something to add , If your mot using the sonnax drum or apply plate make sure you apply and backing plates are perfectly flat and do not assume new is perfectly flat, I have seen brand new plates with a none visible irregularity cause a burn mark on the steel at every position above it or below the top and burn or glaze all the frictions due to that raised place . Of course the thicker the steel plates the less noticeable this becomes but is always true original. Used plates its even more so no matter how nice they look all must be checked they are absolutely flat.
We made a way to make sure they are flat removing a little material till surface is even but a slower but effective way is a flat stone large enough to do it on.
We made a way to make sure they are flat removing a little material till surface is even but a slower but effective way is a flat stone large enough to do it on.
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04-07-2018 | 03:29 PM
#58
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Thanks for the input Frank; it is always greatly appreciated. Can we count on the Sonnax apply plate being absolutely flat or does that need to be checked too? If they are indeed always flat, they might be worth the extra $10 (or so?) over buying the thickest GM apply and backing plates.
04-07-2018 | 04:19 PM
#59
Thanks for the input Frank; it is always greatly appreciated. Can we count on the Sonnax apply plate being absolutely flat or does that need to be checked too? If they are indeed always flat, they might be worth the extra $10 (or so?) over buying the thickest GM apply and backing plates.
On the thickest GM plates while yes thicker is better bear in mind if choosing one or the other opt for thicker steels over the thickest apply and backing plates IMO . Of course we generally start with the thickest apply and backing plates then machine them down till flat.
One rather interesting note , The 700r4 backing /top plate with the bevel is almost always flat or very very close , I am not sure why this is but have noted it.
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06-16-2021 | 08:25 PM
#60
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From: The Niagara Frontier
Here is a picture of what comes with the Sonnax Input Drum kit. Notice that it does not include the input shaft.
Attachment 610656
The primary difference is the top where it supports a screw-in plate and not the snap ring.
Attachment 610657
Attachment 610658
Attachment 610659
The kit includes the Sonnax input drum reinforcement ring which gets pressed on AFTER pressing in the input shaft. To work with the reinforcement ring, a modified aluminum overrun piston is provided. This aluminum overrun piston must be used with an old-style aluminum forward piston (not provided). Since the old-style GM aluminum forward piston had a reputation for cracking, it is suggested to use the Sonnax billet aluminum forward piston. (Another $95).
Attachment 610660
As an alternative, I found an early-production billet overrun piston which works with the new-style OEM steel forward piston; it includes a slightly different reinforcement ring.
Attachment 610661
Comparing them, on the top are the Sonnax Billet Forward piston (extra $95), and the supplied custom-modified Overrun piston and input drum reinforcement sleeve.
On the bottom are a stock GM steel Forward piston, and the billet overrun piston with matching input drum reinforcement ring.
Attachment 610662
The Sonnax supplied apply plate is only .120 thick, compared to the stock .220; however it is uniquely reinforced on the inside and .340 thick there as can be seen in this picture.
Attachment 610663
Since the clearance cannot be adjusted with different thickness backing plates, the only way to change the clearance is with different thickness frictions or steels. For example, Hi-Energy frictions come in .067, .062 and .080 advertised thicknesses. I noticed that different batches had slightly different thicknesses; for example some of the .062 I ordered came in at .065. The Raybestos Blue are advertised at .062, but measured .065. The same was true with steels; I bought two sets of .076 steels from two vendors (TranStar and transmissionpartsusa.com); the first were actually .080 and the other .078. When you multiply these small .002 differences over 8 or 9 units, it is .016 to nearly .020. Here is a picture with specs of the different thickness frictions and steels I experimented with.
Attachment 610664
After getting suggestions from several trans builders, I am aiming for .005 dry clearance PER Hi-Energy friction and .007 clearance PER Blue friction. (In other word, .045 and .063 dry clutch clearance.) Wet, each clutch will be about .001 thicker, so would be aiming for .036 clearance with Hi-Energy and .054 with Blue clutches.
9x BW .067 with 8x .080 steels = .031 (dry) ==> Too tight
9x BW .067 with 8x .078 steels = .047 (dry) ==> Perfect for 9 Hi-Energy clutches
9x Raybestos Blue .062 (.065) with 8x .078 steels = .062 (dry) ==> Perfect for 8 Blue clutches
For those who prefer thicker steels with 8 clutches, I made this measurement:
8x BW .067 with 7x .095 steels = .060 (dry) ==> A bit loose
Real .097 steels should give an excellent .046 clearance, but I only had the GM 4L65E steels, which aren't a good choice anyway because they can only be bought as a kit of 7 frictions and 6 steels. I had a few TranStar 74120D steels which measured a true .097.
Therefore, to build the Sonnax Input drum with 9 BorgWarner Hi-Energy clutches, I would recommend buying the following parts from TranStar or equivalent vendor:
9x 74100D 3-4 Clutch .067 Hi-Energy (Request Borg Warner)
4x 74100CA 3-4 Clutch .062 Hi-Energy (Request Borg Warner)
8x 74120AK 3-4 Clutch .076 Kolene Steel
Depending upon the actual thickness of the steels, you might have to use a few of the .062 frictions to get the desired clearance.
The steels I measured at .078 were from Transmissionpartsusa.com:
8x 35553K 3-4 Clutch .077 Kolene Steel
Again, different vendors and different batches seem to have slightly different thicknesses for the "same" part; therefore you may need an assortment to reach the desired clearance. These frictions and steels are only about $3 a piece.
I will be using the Blue frictions for my actual build. I will report whether the 2-3 shift feels different compared to my current setup with a stock drum and 8x GPX105 frictions.
Attachment 610656
The primary difference is the top where it supports a screw-in plate and not the snap ring.
Attachment 610657
Attachment 610658
Attachment 610659
The kit includes the Sonnax input drum reinforcement ring which gets pressed on AFTER pressing in the input shaft. To work with the reinforcement ring, a modified aluminum overrun piston is provided. This aluminum overrun piston must be used with an old-style aluminum forward piston (not provided). Since the old-style GM aluminum forward piston had a reputation for cracking, it is suggested to use the Sonnax billet aluminum forward piston. (Another $95).
Attachment 610660
As an alternative, I found an early-production billet overrun piston which works with the new-style OEM steel forward piston; it includes a slightly different reinforcement ring.
Attachment 610661
Comparing them, on the top are the Sonnax Billet Forward piston (extra $95), and the supplied custom-modified Overrun piston and input drum reinforcement sleeve.
On the bottom are a stock GM steel Forward piston, and the billet overrun piston with matching input drum reinforcement ring.
Attachment 610662
The Sonnax supplied apply plate is only .120 thick, compared to the stock .220; however it is uniquely reinforced on the inside and .340 thick there as can be seen in this picture.
Attachment 610663
Since the clearance cannot be adjusted with different thickness backing plates, the only way to change the clearance is with different thickness frictions or steels. For example, Hi-Energy frictions come in .067, .062 and .080 advertised thicknesses. I noticed that different batches had slightly different thicknesses; for example some of the .062 I ordered came in at .065. The Raybestos Blue are advertised at .062, but measured .065. The same was true with steels; I bought two sets of .076 steels from two vendors (TranStar and transmissionpartsusa.com); the first were actually .080 and the other .078. When you multiply these small .002 differences over 8 or 9 units, it is .016 to nearly .020. Here is a picture with specs of the different thickness frictions and steels I experimented with.
Attachment 610664
After getting suggestions from several trans builders, I am aiming for .005 dry clearance PER Hi-Energy friction and .007 clearance PER Blue friction. (In other word, .045 and .063 dry clutch clearance.) Wet, each clutch will be about .001 thicker, so would be aiming for .036 clearance with Hi-Energy and .054 with Blue clutches.
9x BW .067 with 8x .080 steels = .031 (dry) ==> Too tight
9x BW .067 with 8x .078 steels = .047 (dry) ==> Perfect for 9 Hi-Energy clutches
9x Raybestos Blue .062 (.065) with 8x .078 steels = .062 (dry) ==> Perfect for 8 Blue clutches
For those who prefer thicker steels with 8 clutches, I made this measurement:
8x BW .067 with 7x .095 steels = .060 (dry) ==> A bit loose
Real .097 steels should give an excellent .046 clearance, but I only had the GM 4L65E steels, which aren't a good choice anyway because they can only be bought as a kit of 7 frictions and 6 steels. I had a few TranStar 74120D steels which measured a true .097.
Therefore, to build the Sonnax Input drum with 9 BorgWarner Hi-Energy clutches, I would recommend buying the following parts from TranStar or equivalent vendor:
9x 74100D 3-4 Clutch .067 Hi-Energy (Request Borg Warner)
4x 74100CA 3-4 Clutch .062 Hi-Energy (Request Borg Warner)
8x 74120AK 3-4 Clutch .076 Kolene Steel
Depending upon the actual thickness of the steels, you might have to use a few of the .062 frictions to get the desired clearance.
The steels I measured at .078 were from Transmissionpartsusa.com:
8x 35553K 3-4 Clutch .077 Kolene Steel
Again, different vendors and different batches seem to have slightly different thicknesses for the "same" part; therefore you may need an assortment to reach the desired clearance. These frictions and steels are only about $3 a piece.
I will be using the Blue frictions for my actual build. I will report whether the 2-3 shift feels different compared to my current setup with a stock drum and 8x GPX105 frictions.