I almost missed what you had said about using a TH400 wave in the forward, so I figured it would be best to recap everything we discussed incase I missed something else lol.
The following is a list of 4L80E hard parts and modifications to perform on a stock 4L80E electronically shifted application with a transbrake that will support 1200+ hp is desired while conforming to SFI rules for the bellhousing. A transmission blanket will be used also. Application is a 2000 camaro.
Hard parts:
- Jakes Aluminum Super Sprag 36 drum
- Jakes 300M input shaft
- Jakes Billet rollerized forward hub
- Reid bellhousing with Jakes adapter plate/machined oil pump
- Jakes D3+ Transbrake
Modifications
Perform all instructions as noted that come with D3 transbrake and do not modify the valve body
Drill a "Lube to Line Bypass" in the pump cover 1/16”
Drill a bleed release hole in the direct drum 1/16”
Enlarge the feed passage on the rear stator support with a 1/8” drill bit at 45 deg angle
Enlarge the seal drain back hole in the pump cover with a 1/4” drill bit
Enlarge the lube hole in the Overrun Clutch housing with a 1/8" drill bit at 45 deg angle
Enlarge the feed passage on the center support with a 1/8” drill bit
Remove/do not install the center lip seal from the direct clutch housing
Remove/omit the second from the top Sealing Ring on the Center Support
No need to plug the valve body where the pressure relief valve is installed when using a D3 brake
No need to use a Sonnax 4L80E LB1 boost valve & PR spring when using a D3 brake.
No need to use an Oversized AFL valve kit or TCC regulator valve bore kit as the D3 brake will already account for this.
There is no need to install a 0.375” cup plug into the case for the dual feed mod if using Jakes D3 brake as the valve body and separator are already modified to account for this.
There are 2 holes on the rear planet used to secure a 2 tang plastic washer. To use a better 4 tang metal washer 34268, use a drill press to make the 2 extra needed holes.
Use a 34127 TH400 wave plate in the forward 34127 (0.060" 12 lug) as it’s stronger than the 4L80E wave plate. Standard 0.077 steels and .080” clutches (5 of each) can be used in the forward along with this wave plate. Clearance should be 0.040” - 0.060”
Use an early TH400 direct piston and machine the work surface for a 0.045 tolerance (dry) using 6 frictions that are 0.080” and 5 steels that are 0.077” and one steel that is .090” which will make initial contact with the piston. Start by machining 0.20” off the work surface area of the piston. The center lip seal on the piston will be omitted. No wave plate will be used in the direct. Make sure that the piston has a check ball in it if the direct drum has no check ball. If the direct drum has a checkball, use a piston with no checkball or remove the checkball in the piston and plug the hole.
Use high spring rate springs with the direct TH400 aluminum piston (The # of springs to use will depend on spring rate) along with a TH400 spring retainer and TH400 snap ring.
Use a heavy duty Snap Ring to secure the intermediate pressure plate – use part number A22878C
The intermediate band should not be used with the aluminum 36 sprag direct drum on a street driven application. The intermediate band must be removed along with other modifications. Shim the intermediate band apply servo flush with the case using washers or a machined shim and then use a snap ring support where the intermediate band anchor pin was. If there are concerns with the piston seal and the bore leaking, remove the entire intermediate servo piston assembly ( Pin, Retainer ring, Oil seal, Piston, spring retainer clip, and Front servo piston spring) and tap the passage for a set-screw. Another method is to drive a check-ball into the feed passage from inside the servo bore. Block the band apply orifice (31b) in the separator plate. Delete the #3 check-ball, plug that hole where the check ball was, and plug the small orifice hole next to it.
The use of c6 alto red frictions R600340 in the intermediate that fit the 36 sprag race will result in a harsher 1-2 shift. You will use a 4L80E wave plate in this setup. If you cannot get the needed clearance of 0.040” to 0.060”, use some R600335 which is thinner at @0.062" and with no oil grooves and replace some of the R600340 frictions.
Reduce the hole in the 2nd-feed orifice (24c) in the separator plate and make it smaller if it’s not drilled conservative to reduce the size for a more conservative 1-2 shift.
Use a TH400 spring retainer and TH400 springs in the intermediate.
Replace the plugs in the pump if they are worn. O-ring plugs from Sonnax can be used if desired but are not necessary. New OEM plugs can be used, or use Sonnax 34200-05K and 34994-14K where applicable.
Use red loctite on the pump body bushing and seal. Stake the bushing. Use a wide body bushing.
Don’t use a standard bushing on the over drive drum which would normally be 34037, use a fluted bushing (groves on the ID) like the one used in the sun gear shaft. This part number is 34037C
Don’t use a standard case bushing, use 34006-SP Sonnax no walk case bushing but install it backwards with red Loctite in a rollerized output setup.
Rollerize the rear output. You will need to purchase part 44200F which is K35412 shims and 9436851 (which is 44211C) to perform this modification.
Ensure that the rear servo pin length is correct.
Air check the various locations in the transmission for leaks
Check all end play tolerances and make sure everything is within pecs. Tolerances are as follows:
Total Rear Unit.....003"-.008" (Rollerized)
Reaction Carrier to Center Support......008"-.015"
Direct Drum to Forward Hub......003"-.008" (Rollerized)
Front unit.....005-.008" more/greater than the Rear Unit
Replace all other pistons, sprags, seals, metal clad seals, washers, bushings, bearings, o-rings, electronics (D3 brake comes with new TCC and shift solenoids) reverse bands, Center Support to Case bolt, 4th Clutch Housing to Case Bolt, filter, internal wiring harness. It’s cheaper to buy steel and friction plate kits and just purchase the additional steels, frictions required than to buy all the clutch pack assemblies individually.
The following bushings should be pressed in, and not banged in.
Sun gear shaft
Both bushings on the stator
Center support bushing
Parts list:
Checklist: