4L60E Build

I "Re-Case" 4L60E's with worn Case Lugs, Some Lug wear is acceptable......Got a picture of the Lugs?

How many 3-4 Frictions?

Wide bands need a little more clearance......070"-.080" is good.

There are 3 Bonded Apply Pistons....3-4, Forward, & Overrun. The only piston that has issues is the 3-4 Apply Piston. SAP "HP-Blue" are advertised as an upgrade.

With a Sonnax 4th Servo....
*Install a Sonnax Pinless Accumulator Piston dome toward the case.
*Original 4th Accumulator Spring against the Plate.
*Disregard the TG HD-2 instructions for 4th Accumulator set-up.

With a Sonnax 2nd Servo....
*You will need to add either a Delco or Trans-Go SK Cushion Spring/s in conjunction with the factory 2nd Servo Cushion Spring. The Blue Spring that comes in the HD-2 is better than nothing though!
*Grind/Cut Slots in the Servo Cushion Spring Retainer like TransGo SK-4L60E instructions say....This will clean-up the 3-2 downshift & help eliminate erratic harsh 1-2 upshifts as the ATF can no longer get trapped behind the Retainer allowing the 2nd Servo Cushion Springs to do their job.

2nd Accumulator....
*Purchase Accumulator Housing 24227211
*Use Inner Cushion Spring that comes with the housing.
*Purchase either GM# 24219942 or GM# 24209794 Outer Cushion Spring & install it in the housing.
**Nothing wrong with using the Phenolic Accumulator Piston here, People can say whatever they want....These pistons LAST!!!!

The reason you don't want to use the Pinless Sonnax in the 2nd Accumulator is it cuts the Range of the Accumulator in half causing overly harsh-thumping 1-2 shifts......That's trash on a street driven transmission!
 
The Orifice highlighted with the red arrow is the Band Release Orifice, This should be .086" which is what late 4L60E plates are from the factory. Do Not drill to .093".

I wouldn't go over .076" for the 1-2 Feed Orifice.

I like the 2-3 Orifice at .093".

The rest of the hole sizes are Okay per HD-2 instructions.

CDC9Qda.jpg
 
I "Re-Case" 4L60E's with worn Case Lugs, Some Lug wear is acceptable......Got a picture of the Lugs?

How many 3-4 Frictions?

Wide bands need a little more clearance......070"-.080" is good.

There are 3 Bonded Apply Pistons....3-4, Forward, & Overrun. The only piston that has issues is the 3-4 Apply Piston. SAP "HP-Blue" are advertised as an upgrade.

With a Sonnax 4th Servo....
*Install a Sonnax Pinless Accumulator Piston dome toward the case.
*Original 4th Accumulator Spring against the Plate.
*Disregard the TG HD-2 instructions for 4th Accumulator set-up.

With a Sonnax 2nd Servo....
*You will need to add either a Delco or Trans-Go SK Cushion Spring/s in conjunction with the factory 2nd Servo Cushion Spring. The Blue Spring that comes in the HD-2 is better than nothing though!
*Grind/Cut Slots in the Servo Cushion Spring Retainer like TransGo SK-4L60E instructions say....This will clean-up the 3-2 downshift & help eliminate erratic harsh 1-2 upshifts as the ATF can no longer get trapped behind the Retainer allowing the 2nd Servo Cushion Springs to do their job.

2nd Accumulator....
*Purchase Accumulator Housing 24227211
*Use Inner Cushion Spring that comes with the housing.
*Purchase either GM# 24219942 or GM# 24209794 Outer Cushion Spring & install it in the housing.
**Nothing wrong with using the Phenolic Accumulator Piston here, People can say whatever they want....These pistons LAST!!!!

The reason you don't want to use the Pinless Sonnax in the 2nd Accumulator is it cuts the Range of the Accumulator in half causing overly harsh-thumping 1-2 shifts......That's trash on a street driven transmission!
Thanks, 7 .67 high energy clutches &6 .95 kolene steels. Lugs on case show no perceptible wear. With gas prices as they are here 4.70 gal regular 😳 its not going to get driven except for snow and moving. Motorcycle is my new horse of choice. Thanks again, only big item I still need is a quality Torque Converter. 👍🛻
 
Hello forgot to ask, what is do special about the gm oe accumulator housing #24227711? Is it markedly different from the stock housing ie my 99 5.3 ls truck? Id have to check it,fairly sure the piston is aluminum on mine. They were fairly tight when removing on teardown. But to be fair i was doing this outside on a bench in low 30’s degree temperature. Will be assembling of course in a properly warm garage, had no room at the time of tear down.
 
I just haven't had the time to go thru in this detail here- but I wanted to talk 3-4 drum, seems to be 4 flavours- 3 very expensive for me.
- sonnax smart drum- too much $$ for me, what type frictions does it take? I think oem type.
- 4L79 has/had three versions, obsolete type with th350 frictions (this is the one I would have been interested in), w custom frictions and stock type frictions- not interested in a wearing part that I have to source custom (especially 4L60/3-4 frictions), is the friction area a source of trouble (where the stock frictions are sufficient)
- sonnax reinforcement kit with thick oem backing plates and HE frictions (GPZ ok?)- where I'm at, with all the nickel and diming- cannot justify sonnax backing plates.
 
Yes I agree the Sonnax smart tech drum is expensive, but if you think about all the upgrades it does seem it would be worth it perfotmance and durability wise,if cost wasn’t an issue. I couldn’t justify it either way. Ive no business getting on it that hard anyway. Thanks for input on the servos. I definitely don’t want banging from gear to gear just driving normally, I do however want a positive engagement and shift if and when I put the pedal down. With all your help im looking forward to a positive outcome with this build. Thanks sincerely.
 
Hello forgot to ask, what is do special about the gm oe accumulator housing #24227711? Is it markedly different from the stock housing ie my 99 5.3 ls truck? Id have to check it,fairly sure the piston is aluminum on mine. They were fairly tight when removing on teardown. But to be fair i was doing this outside on a bench in low 30’s degree temperature. Will be assembling of course in a properly warm garage, had no room at the time of tear down.

Nothing special, But it's ALL new & at $11.00 on Amazon......Why reuse a Accumulator Housing?

Beginning May 11th, 1998, All 4L60E units received Phenolic/Plastic 2nd Accumulator & Forward Accumulator Pistons. Most see this as a cost cutting measure, But it wasn't!

Aluminum Pistons have nasty habit at wearing at the Pin Bore, GM tried softening the Steel Pin in the Housing to alleviate the issue, But this just caused accelerated Pin wear instead.

A lot of testing concluded that a Plastic Piston in conjunction with a "soft" Pin has the best wear characteristics for BOTH parts.

This created an issue for trans builders as there are different hardness Pins with no easy way to match Hard Pins with Aluminum Pistons & Soft Pins with Plastic Pistons if parts have been swapped around.

My guess is if you do have a Aluminum 2nd Accumulator Piston....It was likely installed during a past rebuild or someone was reading all the horror stories about Plastic Accumulator Pistons "breaking".....I say.....Show me one with cracks with under 200,000 miles on it. In fact I rarely see cracks anymore no matter the mileage.


As an extension to this, I either run a Sonnax Pinless Forward Accumulator Piston OR I buy a new GM Plastic Piston as simply swapping in a Aluminum replacement can cause Pin wear!
 
Thanks, 7 .67 high energy clutches &6 .95 kolene steels. Lugs on case show no perceptible wear.

.025" to .028" clearance would be ideal. Once the 3-4 clutch breaks-in....The clearance will be in the low-mid 30's.

If the Case Lugs are in good shape....A "case saver" is not needed.
 
I just haven't had the time to go thru in this detail here- but I wanted to talk 3-4 drum, seems to be 4 flavours- 3 very expensive for me.
- sonnax smart drum- too much $$ for me, what type frictions does it take? I think oem type.
- 4L79 has/had three versions, obsolete type with th350 frictions (this is the one I would have been interested in), w custom frictions and stock type frictions- not interested in a wearing part that I have to source custom (especially 4L60/3-4 frictions), is the friction area a source of trouble (where the stock frictions are sufficient)
- sonnax reinforcement kit with thick oem backing plates and HE frictions (GPZ ok?)- where I'm at, with all the nickel and diming- cannot justify sonnax backing plates.

The Sonnax Smart Drum accepts stock 3-4 Frictions & Steels.

I believe one of the 4L79 drums accepts stock frictions & steels, Their top of the line offering can only utilize 5 of the Load Release Springs which is a deal breaker for me as ALL 10 are needed to break the bond of the clutch pack.

Until I tear this unit down....I'm not sold on the Sonnax replacement Apply & Backing Plates, I have however....Been beating the crap out of it for a year now.

OE GM Apply/Backing Plates, 7 HE Borg Warner .080" frictions, & 6 Kolene .077" Steels is still what I'm using on customer builds up to 500 foot pounds, Above that.....I use a Sonnax Smart Drum with 8 or 9 .080" HE Borg Warner frictions.

I like Raybestos GPZ frictions, But I'm not convinced they're any better than HE Borg Warner's.

I don't care for Raybestos Friction Modules as they haven't kept up with Friction blending technologies for the rest of clutch packs in the 4L60E.....While HE 3-4 Frictions.....The rest are standard Paper frictions you'd find in a 60's/70's transmission.
Borg Warner Forward, Overrun, Reverse Input & Low/Reverse Frictions are Far Superior.

There are a whole host of things that can kill the 3-4 clutch.....3rd Circuit leaks, Poor Band/3-4 Clutch Timing, Overheating the 3-4 Clutch from repeated "Quick Cycling", And poor Line Rise/Low Line Pressure are likely the top 4.

Increasing the Friction Count certainly helps Holding Capacity & Will help with "Quick Cycling" overheat to a certain degree, The more mass (Friction & Steel) the better for BOTH.

The drawback to any solution that can accept 8-9 full thickness Frictions & Steels is the weight added to the end of the Drum....This adds quite the strain on the Stator Support Bushings that already have wear issues with a stock weight drum. A Wide Coated Rear Stator Bushing is only so good. I recommend 100,000 mile refreshes when using a Sonnax Smart Drum.

The 4L60E & it's derivatives will never have the Torque capacity & Longevity of a 4L80E, TH400, Or even a TH350....It's just not physically possible.
 
Thanks again excellent explaining and information. Taking all the above information into account, i have a400&a 350,off topic but an olds 200r4 as well. Now to start utilizing them.
 
My 1 ton Chevy camper by example that has a full floating 14 bolt axle surprisingly has a 350 transmission. 350 engine so to be expected. That transmission is in need of a rebuild as it slips a bit. Was thinking of swapping in a 700r4 k case but if its not going to be durable? Forget it. Id like better mileage as 6 or 7 mpg. Is not doable at 4.70 a gal. Lets go Brdn! 🤣
 
The Sonnax Smart Drum accepts stock 3-4 Frictions & Steels.

I believe one of the 4L79 drums accepts stock frictions & steels, Their top of the line offering can only utilize 5 of the Load Release Springs which is a deal breaker for me as ALL 10 are needed to break the bond of the clutch pack.

Until I tear this unit down....I'm not sold on the Sonnax replacement Apply & Backing Plates, I have however....Been beating the crap out of it for a year now.

OE GM Apply/Backing Plates, 7 HE Borg Warner .080" frictions, & 6 Kolene .077" Steels is still what I'm using on customer builds up to 500 foot pounds, Above that.....I use a Sonnax Smart Drum with 8 or 9 .080" HE Borg Warner frictions.

I like Raybestos GPZ frictions, But I'm not convinced they're any better than HE Borg Warner's.

I don't care for Raybestos Friction Modules as they haven't kept up with Friction blending technologies for the rest of clutch packs in the 4L60E.....While HE 3-4 Frictions.....The rest are standard Paper frictions you'd find in a 60's/70's transmission.
Borg Warner Forward, Overrun, Reverse Input & Low/Reverse Frictions are Far Superior.

There are a whole host of things that can kill the 3-4 clutch.....3rd Circuit leaks, Poor Band/3-4 Clutch Timing, Overheating the 3-4 Clutch from repeated "Quick Cycling", And poor Line Rise/Low Line Pressure are likely the top 4.

Increasing the Friction Count certainly helps Holding Capacity & Will help with "Quick Cycling" overheat to a certain degree, The more mass (Friction & Steel) the better for BOTH.

The drawback to any solution that can accept 8-9 full thickness Frictions & Steels is the weight added to the end of the Drum....This adds quite the strain on the Stator Support Bushings that already have wear issues with a stock weight drum. A Wide Coated Rear Stator Bushing is only so good. I recommend 100,000 mile refreshes when using a Sonnax Smart Drum.

The 4L60E & it's derivatives will never have the Torque capacity & Longevity of a 4L80E, TH400, Or even a TH350....It's just not physically possible.
So did you use the .80 clutch stackup with the Sonnax apply and backing plates in the one you have been beating the crap out of?
 
Yes, I use .080" 3-4 Frictions in all my 4L60E builds, I don't care for 4L65E/4L70E .067" Frictions & absolutely refuse to use aftermarket .062" Frictions.
 
Yes, I use .080" 3-4 Frictions in all my 4L60E builds, I don't care for 4L65E/4L70E .067" Frictions & absolutely refuse to use aftermarket .062" Frictions.
I hope the .67 frictions i am going to use work out. Should i suck if up and get some .80 frictions? And new kolene steels of ? Thickness. I bought the set recommended for the Sonnax apply and backing plate kit. So what do you think? Thanks
 
Sorry.77 kolene steels you did mention. I just really don’t want to put this together unless im sure im using the absolute best possible clutch stackup for durability i can. 4x4’s are not as easy to pull as you know, goes without saying.
 
One knock against the drop-in Sonnax 3-4 Plates is they don't offer varying thickness Backing Plates.
I "Level" the 3-4 Clutch Pack via the 3-4 Apply Housing/Ring, This allows precise clearances once you stack the clutch on the tight side.....Then sneak-up on the desired clearance when leveling the 3-4 Apply plate.

GM Input Drums can vary quite a bit, The easiest way to achieve desired clearance without blueprinting is run a GM Apply Plate & select the proper thickness GM Backing Plate.

Alternative to leveling to achieve proper clearance using Sonnax plates
You might need one .095" steel in the stack.....Example.....
7 .080" Frictions
5 .077" Steels
1 .095" Steel
But don't be surprised if clearance is still off one way or the other.

Sonnax plates are designed to mimic 4L65E/4L70E "HD" Plates far as the space between them & that's why Sonnax recommends using 7 .067" Frictions & 6 .095" Steels as that's what GM used on 65E/70E units.

I like to keep the Mass in the Frictions & thin the Steels just a bit.....It's just works for me. Some builders have good luck with .067" Frictions!

Ask 10 different builders & you'll get 25 different philosophy's;)
 
One knock against the drop-in Sonnax 3-4 Plates is they don't offer varying thickness Backing Plates.
I "Level" the 3-4 Clutch Pack via the 3-4 Apply Housing/Ring, This allows precise clearances once you stack the clutch on the tight side.....Then sneak-up on the desired clearance when leveling the 3-4 Apply plate.

GM Input Drums can vary quite a bit, The easiest way to achieve desired clearance without blueprinting is run a GM Apply Plate & select the proper thickness GM Backing Plate.

Alternative to leveling to achieve proper clearance using Sonnax plates
You might need one .095" steel in the stack.....Example.....
7 .080" Frictions
5 .077" Steels
1 .095" Steel
But don't be surprised if clearance is still off one way or the other.

Sonnax plates are designed to mimic 4L65E/4L70E "HD" Plates far as the space between them & that's why Sonnax recommends using 7 .067" Frictions & 6 .095" Steels as that's what GM used on 65E/70E units.

I like to keep the Mass in the Frictions & thin the Steels just a bit.....It's just works for me. Some builders have good luck with .067" Frictions!

Ask 10 different builders & you'll get 25 different philosophy's;)
Thanks going to try the Sonnax stackup, i will use your stackup on the 700r4 for the camper.
 
Hey Cline- have a look at this thread- bought a band off of Jeg's and wondered what your current experience is with manufacturer markings?
 
Sonnax has never made bands, Alto used to make a good number of Sonnax Branded bands, But like every other manufacturer these days.....Probably can't keep up with demand, So Sonnax looked to other sources.

Though I'm almost certain Alto isn't/wasn't the supplier for the HD Kevlar Band that Sonnax, ATI, TCI, Summit, Jegs & a host of other retailers rebranded as their own....The one with white lettering on the friction material.
I realize that the Sonnax "Stock Photo" shows Sonnax printed on the friction material along with Heavy Duty Kevlar.....But I've never seen Sonnax printed on one in person.

What made you choose a straight Kevlar Band over a "Blended" Pro-Series Band?
 
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