Over the years I have been copying and saving information from posts mostly from PBA/Dana, MaroonMonsterLS1 and vorteciroc concerning 4L60E modifications, mostly dealing with the hydraulic circuits. I realize that you can get into trouble when picking and choosing which combinations of mods to apply, so would you guys check over what I have in mind for this unit?

Trans is going in a 02 Firebird with an LS1 engine making around 450 rwhp. It will have a 4000 stall converter and 410 rear gears. I plan to rev it to 7200-7400 rpm.

This is how I plan to set the transmission up.

Clutch Clearances
Reverse Input Drum .040" To .070". Forward Clutch .030" minimum and .063" maximum 3-4 Clutches .025" minimum and .040" maximum Band clearance of .075" minimum and .125" maximum

A "waved" steel to replace the Belville steel in the Reverse Input Drum.

For the Input Drum I have a homemade copy of the Sonnax Smart-Tech drum with 8 BorgWarner High Energy 3-4 frictions and Kolene steels. TransGo 7-CS clutch spring kit

In the Pump I plan to use a 7 vain rotor.

I will be using Sonnax 2nd and 4th apply servo

Separator Plate Feed Holes
Reverse .104” Band release .104" Check ball Hole that is next to this hole just left of Band Release Hole should be blocked 1-2 feed hole to .099" (with Sonnax 2nd apply servo) 2-3 shift feed hole to .155" 3-4 feed hole to .140" to .155" (with the Sonnax 4th apply servo) 3-2 hole to .120" AFL balance leave it stock Must block the 3-2 control valve to use the larger 2-3 feed hole and band release hole.

I am using the Sonnax HD 2-3 Shift Valve so I will leave out the overrun clutch check ball in the vale body.

In the case I will block off the 4th accumulator feed and leave out the accumulator piston. Also leave the #6 check-ball on the case-side of the separator plate.

Valve body I will be blocking the 3-2 Down Shift (#389) and 3-2 control (#391) valve inboard. Installing a Sonnax HD 2-3 Shift Valve 2 Sonnax Forward & Reverse Abuse Valve kits Sonnax 2-3 O-ring end-plugs
Along with parts from a TransGo HD-2-C kit.

After installing a Sonnax .490 boost valve I will check line pressure and if short of 245 psi I will adjust higher with an EPC Solenoid adjustment.

Thank you for any guidance that you can share with me.
Brian

 

Made some notes in RED for you

 

Sorry, I tried to get the specks for each item on a line by its self put it kept going back. It someone can fix it that wound make it a lot easer to read.

 

Thanks MaroonMonster that was fast. One question, Quote "When blocking the 3-2 downshift valve, take the spring from that valve, and put it INSIDE the AFL spring" I have the TransGo HD-2 kit spring in this location. Should I replace it with the 3-2 downshift valve spring?

 

If you have the HD2 spring there, that is fine

save the 3-2 spring for the next build

 

Looks like a fun build Bbond. I used the white TransGo spring for AFL also. Are you going to vacuum check the VB?

 

MaroonMonster I thought that I saw where you didn't recommend omitting the check ball on the case-side of the separator plate when blocking off the 4th accumulator feed. Did you miss that or did I misunderstand?

 

The #1 checkball right by the accumulator housing?
Omitting is just fine. Also leave out the spring and piston for 4th accum

I'd omit the #6 check ball also for the overrun orifice.
#6 is the checkball right NEXT to the bathtub...do not leave out the one in the bathtub...you'll have a bad day haha

 

Not at this time, the valve body only has 15000 or miles on it since it was last rebuilt. The trans was working fine when I pulled it. I am replacing the rear gears and torque convertor and just decided to freshen it up and try some of the new mods that I have learned from the last rime I had it apart. I just can't leave things alone. Lol

 

Thanks again MaroonMonster. I have the car apart installing V-Band clamps on exhaust to make it easier when removing the trans, I'm also changing rear gears and torque converter. So it maybe a week or two before the torque converter comes in and I am able to get it all back together. I am making a lot of changes all at once, I hope it doesn't bite me in the butt. I'll report back to let everyone know how it turned out.

 

Sorry for the long wait on an update, it took over 5 weeks for the torque converter to come in. All of the trans mods worked out well. The trans shifts a little firmer than before, especially the 3-4 shift but not too hard. I ended up with a max line pressure of 240 psi, I was hoping for a little more but this will be okay. I did find that the input shaft was leaking where it presses into the drum so I had to reseal it again. The last time I sealed it I used red Loctite. This time I used some Loctite 640 Sleeve Retainer, hopefully this will work better.

As for the exhaust mods and ring & pinion change. The exhaust v-band clamps came out really good, I should have done this a long time ago. The gears are making a little noise at highway speeds but not real loud. You know what they say just turn up the radio. It has been raining here every time the track would have been open for the last week and a half so no time sleeps yet. The weather forecast looks good for this coming Wednesday, so helpfully we'll be able to make a few passes then.

Thank you everyone for your input.
Brian

 

Increasing the line pressure will firm up the shifts even more so... 240 Psi is perfectly fine for the HP listed in your signature.

The 3-4 up-shift is nice and firm with no accumulator.


What model differential are you using?
What type of carrier are you using?
Any additional pre-load on the clutches or cones?
What is the Pinion depth and pre-load? Crush or solid sleeve?
What is the backlash?
What is the carrier bearing pre-load?

 

Thanks vorteciroc the trans did turn out nice. The diff noise is not all that bad, I'm just a perfectionist and want everything I do to be prefect. That gets me into trouble sometime because I won't leave well enough alone. If the noise gets louder I'll buy another gear set and try it again.

 

Okay sounds good, and as long as the gear pattern looked good upon assembly...
it should not be too bad.

Make sure the Drive-Shaft and U-Joints are good...
When bad, there can be excessive load on the pinion gear.

 

Just an update on how my trans has been doing since the last round of upgrades and rebuild. All shifts are quick and firm. The 3-4 shift with the 4th accumulator bypassed is very nice, not too harsh. I've had it at the race track and the car has been running in the sub 7.40s - 7.30s in the 1/8. At the last race we made it to the finals with my son driving and it broke the diff at about the 60ft mark.

I got an open diff carrier and installed a mini spool in it and the car was still bound up. Thinking that maybe when the diff broke that it took out the transmission output shaft with it. So we pulled the trans and this is a few pics of what we found. The low roller race that come with the Sonnax Smart Shell had broken. All of the clutch packs looked great, so that is a plus.

Looking online At WIT, Summit and Jegs it seems that no one has a Sonnax Smart Shell in stock. Does anyone know where I can source one? I would really like to have this thing going again by the weekend.

 

Now that is IMPRESSIVE!

The Drive-Line clearly took a HIT!

Sorry, I would see If Dana can part with one.
Let me know if you need his (Personal) Phone Number.

 

Make certain that the Output-Shaft is not bent, twisted, or have Spline damage.

 

It looks okay, I have another one that I can use just to be safe. Is this common for the low roller race to break like this. I have never seen this before? I have broken the forward sprag a few times but never the low roller.

 

I have never broken the stock or Sonnax version...

LOL! that's why I said: "Now that is IMPRESSIVE!"

I have seen Differential/ Drive-Shaft failure cause somewhat similar breakage inside the Transmission.
Just not the Inner-Race of the Low Roller-Clutch.

 

Thanks for your input vorteciroc. I have another trans that I am going to harvest the gear set out of, all I need after a good cleaning is a sun shell, filler and a few gaskets.