4L78 clearance
Thread Starter
Teching In
Joined: Dec 2019
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From: North Branch, MI
4L78 clearance OK have a question, doing a final check on clearances. Using Masons 4L78 drum, (standard diameter frictions and steels, with a billet cap). Has 7/.078 steels, 1/.098 steel and 8 Reybestos Stage 1 frictions. And a Sonnax backing plate. Using the TG 7-CS springs, along with his load release springs.
With the cap on, load release springs in, and the set screw loosely set I'm getting .052.
I have a .106 kolene I can swap for the 098 and bring clearance down to .045ish.
Should I stick with the +50 or go smaller? Does it matter even?
7 - .078 steels 1 -.097 steel Frictions are .080 Raybestos Stage 1s. =.052
W/.106 steel =.045
With the cap on, load release springs in, and the set screw loosely set I'm getting .052.
I have a .106 kolene I can swap for the 098 and bring clearance down to .045ish.
Should I stick with the +50 or go smaller? Does it matter even?
7 - .078 steels 1 -.097 steel Frictions are .080 Raybestos Stage 1s. =.052
W/.106 steel =.045
TECH Junkie
Joined: Jun 2008
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From: Nitro Alley
If the Input-Drum uses Stock size Frictions and Steels...
I VERY STRONGLY recommend that you do not use the Raybestos Stage-1 Frictions.
Stage-1 Frictions are good Frictions, but NOT for the 4L60E 3-4 Clutch.
Use Borg-Warner High-Energy Frictions (the later Green Frictions, not the earlier Tan Frictions) or Raybestos GPZ Frictions.
For the 3-4 Clutch clearance; target 0.030" to 0.035".
You also should get the 2-4 Band clearance to 0.060" in addition for 2nd gear to 3rd gear shift timing.
I VERY STRONGLY recommend that you do not use the Raybestos Stage-1 Frictions.
Stage-1 Frictions are good Frictions, but NOT for the 4L60E 3-4 Clutch.
Use Borg-Warner High-Energy Frictions (the later Green Frictions, not the earlier Tan Frictions) or Raybestos GPZ Frictions.
For the 3-4 Clutch clearance; target 0.030" to 0.035".
You also should get the 2-4 Band clearance to 0.060" in addition for 2nd gear to 3rd gear shift timing.
Thread Starter
Teching In
Joined: Dec 2019
Posts: 12
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From: North Branch, MI
I had originally planned on using GPZ. Then got with Mason on this drum. He sent it with stage 1s. Was his thought they would serve me better than GPZ.
Just read that Sonnax recommends. 050-060 for their drums. That should apply here to as well ild think.
Mason said 50 was fine. But could change it around if I wanted.
Honestly just gonna quit thinking about things so much and send it. Lol
And that's what I'm shooting for. Have done most other things that are "standard" with you and a few of the others.
This was a last minute, thought I wanted to air out.
Just read that Sonnax recommends. 050-060 for their drums. That should apply here to as well ild think.
Mason said 50 was fine. But could change it around if I wanted.
Honestly just gonna quit thinking about things so much and send it. Lol
And that's what I'm shooting for. Have done most other things that are "standard" with you and a few of the others.
This was a last minute, thought I wanted to air out.
TECH Junkie
Joined: May 2012
Posts: 3,050
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From: Poplarville, MS
I had originally planned on using GPZ. Then got with Mason on this drum. He sent it with stage 1s. Was his thought they would serve me better than GPZ.
Just read that Sonnax recommends. 050-060 for their drums. That should apply here to as well ild think.
Mason said 50 was fine. But could change it around if I wanted.
Honestly just gonna quit thinking about things so much and send it. Lol
And that's what I'm shooting for. Have done most other things that are "standard" with you and a few of the others.
This was a last minute, thought I wanted to air out.
Just read that Sonnax recommends. 050-060 for their drums. That should apply here to as well ild think.
Mason said 50 was fine. But could change it around if I wanted.
Honestly just gonna quit thinking about things so much and send it. Lol
And that's what I'm shooting for. Have done most other things that are "standard" with you and a few of the others.
This was a last minute, thought I wanted to air out.
Thread Starter
Teching In
Joined: Dec 2019
Posts: 12
Likes: 0
From: North Branch, MI
I did listen to his advice. That's what it is, advice. Using different frictions and changing the clearance that much would require a complete different set. Then ild be going against others advice. Going to 030 is also under Sonnax advice.
There's a huge difference of opinion in alot of things with these transmissions. I've listened to the advice of and seen recommendations of alot. Can't follow them all though.
There's a huge difference of opinion in alot of things with these transmissions. I've listened to the advice of and seen recommendations of alot. Can't follow them all though.
TECH Junkie
Joined: Jun 2008
Posts: 3,202
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From: Nitro Alley
Airing-out your thoughts/ questions is fine.
0.050" - 0.060" for the 3-4 clutch on it's own is fine...
The reason why myself and other builders who specialize in the 4L60E Family Transmissions recommend a target of 0.030" is for the timing of the 2-3 shift.
The 2-3 shift is a synchronized shift... meaning that multiple components are applying and releasing at the same time.
When the timing is not correct, a tie-up or a flair occurs.
This is why I included the 0.060" 2-4 Band clearance as well.
Orifice sizing is also a factor.
As long as your 2-3 shift goes smoothly, you can leave the clearances where they are.
The 0.030" and 0.060" clearances generally work well...
Especially with BW HE frictions and one of the ONLY times I will recommend Kolene Steels.
0.050" - 0.060" for the 3-4 clutch on it's own is fine...
The reason why myself and other builders who specialize in the 4L60E Family Transmissions recommend a target of 0.030" is for the timing of the 2-3 shift.
The 2-3 shift is a synchronized shift... meaning that multiple components are applying and releasing at the same time.
When the timing is not correct, a tie-up or a flair occurs.
This is why I included the 0.060" 2-4 Band clearance as well.
Orifice sizing is also a factor.
As long as your 2-3 shift goes smoothly, you can leave the clearances where they are.
The 0.030" and 0.060" clearances generally work well...
Especially with BW HE frictions and one of the ONLY times I will recommend Kolene Steels.
Thread Starter
Teching In
Joined: Dec 2019
Posts: 12
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From: North Branch, MI
OK. Yea Ive come to learn the 2-3 both up and down seems to depend mainly on timing.
. 060 band clearance is one thing that has been said over and over and one I planned on doing.
I'm using a Sonnax kevlar wide band(new drum), have a corvette 2nd and Sonnax billet 4th. 3rd feed is 128, br 98.
Those were choose simply from the notes I took from Danas suggestions. And those are smaller than what equally built trans he's made recommendations on.
The whole 3/4 clearance thing has got me because I've seen so many people, Mason whose drum setup it is, Sonnax, Alto, and "others" talk about 3/4 stacks with 8 and 9 frictions should be at or around 50 to aide in cooling.
Then there's you and Dana both I've seen say 30.
Like I said I can swap one steel for a thicker on and drop the clearance to 45 or less.
I know you'd want GPZs and .030, but with what I have already and @ .043-.045 do you know there will be an issue, or just think it's possible?
If I could restart and do all this **** over I would, I've wasted alot of time and spent more money than I needed to making dumb newb mistakes and choices. Just trying to make best with what I have now, lol.
Oh, and why do you not like stage 1s in a 8 stack 4L78 3/4, but have said you do for the 8 stack 4L79 3/4?
. 060 band clearance is one thing that has been said over and over and one I planned on doing.
I'm using a Sonnax kevlar wide band(new drum), have a corvette 2nd and Sonnax billet 4th. 3rd feed is 128, br 98.
Those were choose simply from the notes I took from Danas suggestions. And those are smaller than what equally built trans he's made recommendations on.
The whole 3/4 clearance thing has got me because I've seen so many people, Mason whose drum setup it is, Sonnax, Alto, and "others" talk about 3/4 stacks with 8 and 9 frictions should be at or around 50 to aide in cooling.
Then there's you and Dana both I've seen say 30.
Like I said I can swap one steel for a thicker on and drop the clearance to 45 or less.
I know you'd want GPZs and .030, but with what I have already and @ .043-.045 do you know there will be an issue, or just think it's possible?
If I could restart and do all this **** over I would, I've wasted alot of time and spent more money than I needed to making dumb newb mistakes and choices. Just trying to make best with what I have now, lol.
Oh, and why do you not like stage 1s in a 8 stack 4L78 3/4, but have said you do for the 8 stack 4L79 3/4?
Last edited by SSIINN; May 12, 2021 at 05:42 PM.
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TECH Junkie
Joined: Jun 2008
Posts: 3,202
Likes: 1,390
From: Nitro Alley
Ehh... Sonnax.
Sometimes they produce a great product that is really beneficial for the Transmission being worked on...
Other times I really wonder what Sonnax was thinking when they made certain products that do not benefit said Transmission.
The Sonnax Kevlar 2-4 Band for the THM700-R4/ 4L60E Family is one of those products that boggles my mind.
I have had some real experience with Kevlar and lead projectiles being fired at it...
Kevlar in my opinion does not belong in an Automatic Transmission.
My engineering experience tells me that Kevlar was chosen due to it's ability to combat heat/ burning...
But it does not do so well in terms of grabbing the clutch drum.
If you wish to use a wide 2-4 Band; use the Alto Carbonite wide Band.
This is probably the ONLY Alto part that I will ever recommend.
0.043" is not bad...
It is way better than the clearance used from the factory.
Sometimes they produce a great product that is really beneficial for the Transmission being worked on...
Other times I really wonder what Sonnax was thinking when they made certain products that do not benefit said Transmission.
The Sonnax Kevlar 2-4 Band for the THM700-R4/ 4L60E Family is one of those products that boggles my mind.
I have had some real experience with Kevlar and lead projectiles being fired at it...
Kevlar in my opinion does not belong in an Automatic Transmission.
My engineering experience tells me that Kevlar was chosen due to it's ability to combat heat/ burning...
But it does not do so well in terms of grabbing the clutch drum.
If you wish to use a wide 2-4 Band; use the Alto Carbonite wide Band.
This is probably the ONLY Alto part that I will ever recommend.
0.043" is not bad...
It is way better than the clearance used from the factory.
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TECH Junkie
Joined: Dec 2012
Posts: 3,615
Likes: 1,327
From: Iowa
The thing is
set the drum up with .030
and by the time it has gone 1000 miles, it'll be .050
gpz/borg HE both "shed" a bit
.001-.0015 per friction is pretty normal and once it has shed, it usually does not continue to unless you burn the pack up.
.0015 x 8 frictions is a good bit of clearance
set the drum up with .030
and by the time it has gone 1000 miles, it'll be .050
gpz/borg HE both "shed" a bit
.001-.0015 per friction is pretty normal and once it has shed, it usually does not continue to unless you burn the pack up.
.0015 x 8 frictions is a good bit of clearance
OK. Yea Ive come to learn the 2-3 both up and down seems to depend mainly on timing.
. 060 band clearance is one thing that has been said over and over and one I planned on doing.
I'm using a Sonnax kevlar wide band(new drum), have a corvette 2nd and Sonnax billet 4th. 3rd feed is 128, br 98.
Those were choose simply from the notes I took from Danas suggestions. And those are smaller than what equally built trans he's made recommendations on.
The whole 3/4 clearance thing has got me because I've seen so many people, Mason whose drum setup it is, Sonnax, Alto, and "others" talk about 3/4 stacks with 8 and 9 frictions should be at or around 50 to aide in cooling.
Then there's you and Dana both I've seen say 30.
Like I said I can swap one steel for a thicker on and drop the clearance to 45 or less.
I know you'd want GPZs and .030, but with what I have already and @ .043-.045 do you know there will be an issue, or just think it's possible?
If I could restart and do all this **** over I would, I've wasted alot of time and spent more money than I needed to making dumb newb mistakes and choices. Just trying to make best with what I have now, lol.
Oh, and why do you not like stage 1s in a 8 stack 4L78 3/4, but have said you do for the 8 stack 4L79 3/4?
. 060 band clearance is one thing that has been said over and over and one I planned on doing.
I'm using a Sonnax kevlar wide band(new drum), have a corvette 2nd and Sonnax billet 4th. 3rd feed is 128, br 98.
Those were choose simply from the notes I took from Danas suggestions. And those are smaller than what equally built trans he's made recommendations on.
The whole 3/4 clearance thing has got me because I've seen so many people, Mason whose drum setup it is, Sonnax, Alto, and "others" talk about 3/4 stacks with 8 and 9 frictions should be at or around 50 to aide in cooling.
Then there's you and Dana both I've seen say 30.
Like I said I can swap one steel for a thicker on and drop the clearance to 45 or less.
I know you'd want GPZs and .030, but with what I have already and @ .043-.045 do you know there will be an issue, or just think it's possible?
If I could restart and do all this **** over I would, I've wasted alot of time and spent more money than I needed to making dumb newb mistakes and choices. Just trying to make best with what I have now, lol.
Oh, and why do you not like stage 1s in a 8 stack 4L78 3/4, but have said you do for the 8 stack 4L79 3/4?
Also, make sure you calibrate your dipstick to establish the correct full mark. We talked about this already...
Last edited by 2BFAST; May 13, 2021 at 09:42 AM.
TECH Junkie
Joined: Dec 2012
Posts: 3,615
Likes: 1,327
From: Iowa
Yes
0.050 will work fine
The reds will work fine
I'll be putting tan frictions in my personal camaro this summer just to prove a point
Friction material does not matter as much as 99% of guys think it does.
The borg setup is nice and common to use because they are reliable, have great quality control, and are priced fairly compared to "fancy" frictions.
They take heat fairly well also.
But the reds will treat you just fine and the reds share many of the same qualities listed above.
The kevlar band doesn't have as much friction coefficient and it is much much more prone to wearing a drum out than other options
For MOST power levels...a wide band is prettymuch not necessary at all anyway
0.050 will work fine
The reds will work fine
I'll be putting tan frictions in my personal camaro this summer just to prove a point
Friction material does not matter as much as 99% of guys think it does.
The borg setup is nice and common to use because they are reliable, have great quality control, and are priced fairly compared to "fancy" frictions.
They take heat fairly well also.
But the reds will treat you just fine and the reds share many of the same qualities listed above.
The kevlar band doesn't have as much friction coefficient and it is much much more prone to wearing a drum out than other options
For MOST power levels...a wide band is prettymuch not necessary at all anyway
Thread Starter
Teching In
Joined: Dec 2019
Posts: 12
Likes: 0
From: North Branch, MI
At this point not getting the kolenes is just another thing I probably did wrong.
But live and learn... And learn I have.
At least I have the ability and more knowledge than I did before this started. Will just use it on the next trans. I'm sure there will be a next... Lol
TECH Junkie
Joined: Jun 2008
Posts: 3,202
Likes: 1,390
From: Nitro Alley
The frictions and steels that you have will be just fine.
I simply do not prefer them over the BW HE frictions...
Also 99% of the time I will say not to purchase Kolene steels...
The 3-4 Clutch pack is one of the few places that I prefer Kolene steels.
You shouldn't have any issues, as long as the Line-Pressure and separator-plate is squared away.
I simply do not prefer them over the BW HE frictions...
Also 99% of the time I will say not to purchase Kolene steels...
The 3-4 Clutch pack is one of the few places that I prefer Kolene steels.
You shouldn't have any issues, as long as the Line-Pressure and separator-plate is squared away.