Just wanted to ask the question , is anyone successfully running a 4l60e up to 8000rpm or more ?
if so , what modifications were needed?

 

I dont have an answer but dang I'd like to see the results! Please post up a vid when you get there! Good LUCK!

 

Slide locked for maximum volume
7 vane rotor
properly sized separator plate orifices
7-cs springs in the 3/4
I'd run stiff springs in the reverse drum with an added bleed hole
extra bushing support in a couple key areas...mainly both sun gears, case, and stator tube
Kill the 4th accum and use the additional spray lube to help the rear
a little extra 3/4 clearance won't hurt as long as you properly time the 2-3 shift

 

Reverse-Input Clutches can be a pain in the *** to deal with at High-RPM.


As already said; stiff Return-Springs for the Reverse-Input Piston, and a Bleed-Hole in the corner of the Drum under the Piston.

 

See notes above

 

There are different Reverse Input Piston Return-Springs that can be used...
I have used many different Springs that were sold for Power-Glide, THM200-4R, and THM350 Trans-Brakes.

The Rear Sun-Gear Bushing ends-up being one of the most-important Bushings as a "Floating Gear-Train"/ Center-Supprtless Design Transmission.
On every unit, I would Install Two Factory Bushings on-top of one another...
Instead of the Sonnax Wide Bushing (that can be problematic with fitment).

Two OEM Bushings creates a slightly wider surface area over the Sonnax Bushing.
Be mindful of the Lube-Holes!

The Case Bushing width fits the Rear Ring-Gear VERY well... I am happy with it.
The case could possibly accommodate a wider Bushing... if desired.

Sonnax offers Wider Bushings for the Stator-Support that work well.

Something that I usually do away-with is the Front Sun-Gear being retained by the Tabs of the Sprag-Assembly.
I almost always enlarge the Output-Shaft Lube-Passages for the Sprag-Assembly...
and ensure that the Front Sun-Gear Bushing placement is ideal for proper lubrication.

The Lube Oil between the Output-Shaft and the Reaction-Shaft can also be increased.
More Lube between the Output-Shaft and the Reaction-Shaft...
as well as the Reaction-Shaft, and the Rear Sun-Gear.

More or less... this should suffice for Higher RPM Builds.
Centrifugal apply of the Reverse-Input Clutch, and Pump Volume are the two more important things to deal with.

Good luck, and have fun!

 

I was hoping that Maroon Monster would still add to this further
...as I believe he is the most experienced builder on the forum, of high-performance 4L60E Units.
I always find his contributions to be of value.

Even when he is just breaking-*****/ havin' fun!


I feel like he has not been receiving as much credit as he deserves recently...
So if you guys see him Posting, it is always nice to receive a: "Thank You", in this Business.

 

Thankyou for all the replies , the trans will be purely used at the strip, engine is making peak power @ 8400rpm and shifting @ 8700rpm. Still tossing up whether to stick with the 4l60e or convert to th400.
it's a 355 cube holden engine , 685hp , 493 ftlb naturally aspirated.

 

If it’s just strip go turbo 400. Then you don’t have to worry how many passes it will stay a live. Also the amount of money to keep that trans a live at that rpm is not worth it imo

 

The TH400 would be more problematic at those higher Engine Rpms...
Unless going to lighter aftermarket Forward, and Direct Drums.

 

I would add that the placement of the bleed checkball on the 3-4 clutch is an issue. It needs to be taken care of.

 

I am assuming you are referring to the Input-Drum Check-Ball Capsule that is under the 3-4 Clutch Piston.
I have seen some of the Aftermarket replacement Check-Ball Capsules be too tall and interfere.
What is your recommendation here?

Only after sealing-up the many, many leaks in the 3-4 Clutch and 3rd Accumulator Circuits:
I personally add a 0.060" bleed under the 3-4 Clutch Piston (in addition to the Check-Ball Capsule) for Higher RPM Units...
as well as a bleed under the Reverse-Input Piston (I see more issues here with unwanted centrifugal-apply).

 

If any of you are looking to go with a THM400, and have a high-Reving Engine...
There is an amazing Aftermarket Forward-Drum/ Direct-Drum, that has been around for over 20-years now.
Look up John Kilgore Racing/ THM400 Transmissions.
He is an amazing Builder! ...and has designed his own Drums, that I am referring to.
(John Kilgore Super-Lite THM400)





Otherwise, more traditional Drums are also produced in Alloys of Aluminum, and some in Titanium.

 

what do those units cost ?

 

You don't want to know...

 

Plus the OP is in Australia, shipping would cost an arm and a leg...

 

It's a modified TH180 drum, Kilgore has always been an innovator in the transmission field. I remember running into John at the Long Beach performance swap meet held here in Cali when he introduced this set up.