Keep finding clutch on newly rebuilt 60e
I would say that 80% of the pro performance builders I have spoken to or have posted here prefer a 7 friction setup over an 8 friction setup. The main exception would be member PBA (Dana) who's widely used kits and transmissions use 8 or even 9 frictions.
His current performance kit uses 8x thick 0.080 frictions and thinner steels and plates.
Some of the sponsors have told me what they do, but I don't want to post any "secrets" they unintentionally told me, so lets just keep it at "80%". Personally, I run one more friction, e.g. 8 in a normal input drum, 9 in the Sonnax Smart Tech drum, but then I pull and at least partially rebuild my trans every year. My hypothesis is that while a higher count friction setup might hold better, it may also wear faster.
His current performance kit uses 8x thick 0.080 frictions and thinner steels and plates.
Some of the sponsors have told me what they do, but I don't want to post any "secrets" they unintentionally told me, so lets just keep it at "80%". Personally, I run one more friction, e.g. 8 in a normal input drum, 9 in the Sonnax Smart Tech drum, but then I pull and at least partially rebuild my trans every year. My hypothesis is that while a higher count friction setup might hold better, it may also wear faster.
Heat is the enemy...and the clutch's (any clutch) ability to both tolerate and dissipate it is key to its longevity. Thin discs don't take heat well at all, and will warp and cone at a even moderate levels of heat. Plus, on the 4L60E, the need to run the stack on the tight side to clean up the dual-event 2-3 shift comes into play as well. Once the discs begin to cone, they drag on each other when the clutch is disengaged, and game over...
The other, often overlooked factor is the apply and backing plates. Most setups with 8 or 9 discs (including the god-awful Alto "commercial" pack) use a very thin backing plate in order to fit that last friction in there. These thin backing plates flex badly under load. Once they flex, they are no longer flat and the effective apply area of that last friction diminishes to just the outer edge, adjacent to the snap ring. Even if the clutch doesn't burn up, the last couple of frictions are not doing much for you. The same goes for the apply plate. Due to the design of the 4L60E 3-4 clutch apply hardware, the apply force is delivered from the apply ring to the apply plate at just five points at the very outer edge of the apply plate. With the apply force at the outer edge, and the "load" (the clutch discs) toward the middle, this plate is constantly being loaded into a cone shape. Anything less than the latest design, hardened GM apply plate of proper thickness will result in the same diminished apply area as the backing plate scenario above.
Off of soap box now...
The other, often overlooked factor is the apply and backing plates. Most setups with 8 or 9 discs (including the god-awful Alto "commercial" pack) use a very thin backing plate in order to fit that last friction in there. These thin backing plates flex badly under load. Once they flex, they are no longer flat and the effective apply area of that last friction diminishes to just the outer edge, adjacent to the snap ring. Even if the clutch doesn't burn up, the last couple of frictions are not doing much for you. The same goes for the apply plate. Due to the design of the 4L60E 3-4 clutch apply hardware, the apply force is delivered from the apply ring to the apply plate at just five points at the very outer edge of the apply plate. With the apply force at the outer edge, and the "load" (the clutch discs) toward the middle, this plate is constantly being loaded into a cone shape. Anything less than the latest design, hardened GM apply plate of proper thickness will result in the same diminished apply area as the backing plate scenario above.
Off of soap box now...
Excellent info and explanation Dynamic.
Due to the coning issue, several pro builders have suggested always replacing the apply plate, even if it looks OK. Do you agree with that? Or only if it has more than .001" of warpage?
Due to the coning issue, several pro builders have suggested always replacing the apply plate, even if it looks OK. Do you agree with that? Or only if it has more than .001" of warpage?
The 3-4 clutch apply and backing plates are a zero-tolerance area in my book. It's rare to ever find ones that have been in service that are still in acceptable condition. Plus, there is an updated design to both plates, although I don't recall exactly when GM changed them to be perfectly honest.
But the reality is that both plates are cheap, and all of my builds get new ones, and all of our parts packages include them.
But the reality is that both plates are cheap, and all of my builds get new ones, and all of our parts packages include them.
The OP did write 60e in the title.
The advice on the 3/4 clutch applies to any 700R4 through the latest 4L70E.
Perhaps the OP will update us on what he really has, especially if he asks for advice on anything else.
The advice on the 3/4 clutch applies to any 700R4 through the latest 4L70E.
Perhaps the OP will update us on what he really has, especially if he asks for advice on anything else.
https://ls1tech.com/forums/member.php?u=219882
You'd think he had a 700R4 / 4L60 based on the link above.
Or change his info.....
You'd think he had a 700R4 / 4L60 based on the link above.
Or change his info.....
Anyways thank you guys for the info. It's really interesting and can see & enjoy when the experienced are learning new things & techniques from other members. That's why I make a million threads about the same damn thing. Lol you can never have enough Information! 😎
The 3-4 clutch apply and backing plates are a zero-tolerance area in my book. It's rare to ever find ones that have been in service that are still in acceptable condition. Plus, there is an updated design to both plates, although I don't recall exactly when GM changed them to be perfectly honest.
But the reality is that both plates are cheap, and all of my builds get new ones, and all of our parts packages include them.
But the reality is that both plates are cheap, and all of my builds get new ones, and all of our parts packages include them.
If you can, could you provide part numbers on the components you use? You had said that:
I use 7x .080" Borg Warner high energy frictions, 6x .076" steels, OEM .220" apply plate and OEM .193" backing plate. With an OEM .093" snap ring, this will have around .030"-035" clearance.
and:
...all of our parts packages include them.
I'm not saying these parts will solve my problem, I plan on checking every bushing and seal thoroughly, I'd just like to have a better chance of success than what I've had in the past.
I suggest installing the Sonnax input drum reinforcement ring after pulling the input shaft out of the drum and reinstalling it with Loctite. This not only eliminates one common leakage point, but also strengthens this somewhat weak area.
Rapid failure of the 3/4 clutch (with modest
Rapid failure of the 3/4 clutch (with modest








