Hello,
I am going to do a filter change on my 2 year old 4l60E tranny OVH. So been thinking about doing the following two recommended modifications.
I been reading about blocking the 3-2 shift valve and the 3-2 control valve inboard, making them inoperative.

1. Question is why? Is the purpose to allow a down shift only at WOT?
So lets say you are going up a hill at around 30 MPH in third, it will not down shift but lug away up the hill in 3rd?
Please tell me what I am missing.

Note: for the shifting hard parts----
I have a Sonnax Performance shift kit with the TCC limiter, [minus the servo release check valve.] Sonnax Forward & reverse abuse valve kit. Sonnax 3-4 O-ring end plug kit. Sonnax heavy duty 2-3 Shift valve. Corvette 2nd gear servo, Sonnex 4th gear servo and a Yank truck Thruster 3000 converter. If I remember about .040" 3rd clutch clearance and .073" band clearance.

2. Question, Right now I have the AFL balance oil hole drilled to .052" and the recommended size is .093". Would drilling this out change the way it shifts?
I had many trany fluid showers from taking off the valve body trying to get the part throttle 2-3 shift from hanging up. So I do not want to mess that up. It has just alittle 2-3 hang up ---sometimes under part throttle. So I am planning on going from .101" to .113" [sneaking up very slowly.] the 3rd shift plate hole and from .093" to .100" on the band release hole.

thanks in advance.

 

Blocking these 2 valves will not affect when the vehicle tries to make a 3-2 downshift. That is still controlled by the computer.
These valves are just used to affect how much time it takes between when the computer commands the shift, and when it actually occurs. (we're talking in the range of tenths or hundreths of seconds difference here. Not multiple seconds)

The two 3-2 valves, in stock form, are just a VERY overcomplicated method of offering multiple exhaust paths of varying distance and flow capability.
Blocking them gives one fixed exhaust path, and you can control the size and speed of exhaust by using the "band release" hole we always talk about on this forum.

Blocking the valves eliminates large circuit leaks in the 3rd gear circuit and cures cross leaking from 2/3 fluid paths.
Also, it gives the builder control of the exhaust path. Once you change clutch count, clutch clearance, band width, servo size, band clearance, shift feed orifice size, pressure, etc...all of the factory programming/timing for the 3-2 shift goes out the window. SO, when the valves are blocked, each builder can use the separator plate to control shift feel for both UP and DOWN shifts.

I block both of these valves all the time. Even on my fiance's grandma-mobile that needed the 60e redone. She notices shift feel and timing better than most guys I know...and she has no complaints. And believe me...because I'm the builder I'd normally get fielded with more complaints than from a usual customer ha!



As for the AFL balance (and the hydraulic theory here correlates to the TCC balance also, so keep that in mind) That small orifice is opposing spring force (TCC Signal oil in the TCC lineup. But the oil acts like a spring-applies force)
So, the spring is trying to bottom the valve in its bore, which creates a path for line pressure to bleed its way into the AFL circuit. The deeper in the bore the valve is pushed by the spring, the more line makes it into the AFL. So, for example when transgo includes the spring that goes inside the stock AFL spring, they are adding more pressure to keep the spring bottomed in it's bore. This raises AFL pressure and also gives a larger path for more volume to help overcome AFL circuit leaks in worn VB's.

When you drill that orifice larger, you actually feed more fluid to the backside to push back against that spring force harder. Which un-does all of the effort of putting more spring force in there. It helps put some of the feedback loop into play.
I think .093 is much too large. IF I'm going to modify this hole from factory, I go no larger than .078

Leaving it stock will have the end result of just increasing AFL pressure and volume.
AFL is used to feed the solenoids in the VB. All 5.
*3-2 solenoid (which if you're blocking the valve....doesn't matter now. You're just leaving it in the bore to seal the bore and you're just plugging it in so the computer won't get pissed off)
*TCC pwm solenoid. MOST people are blocking that valve, using TransGO or SONNAX or FITZALL. so the TCC pwm isn't doing anything now. those are all self regulating systems. (or blocking the stock valve...also makes tcc pwm useless)
*shift solenoids. These are simple on/off solenoids and they already are orificed down. The factory uses a small orifice before both shift noids to keep overall volume down because the solenoid can only exhaust so much fluid due to its internal bleed diameter. Some people will drill these orifices larger in an attempt to bandaid low AFL pressure, but it's a fools errand. Leave the orifice stock, and you could BLOCK the AFL inboard and it wouldn't matter. The solenoid exhaust would be larger than the orificed feed, so it would always exhaust.
*PCS-this is where abnormally high AFL pressure would cause a noticible change. The noticible change would be prettymuch the same affect as turning the PCS "screw" on the backside of the solenoid. It's just going to bump the base pressure and pressure across the board. In my history/experience and in practice, an extra 15psi on a 60e never hurt anybody. It extends the life of the trans and I've never had a single customer complain about harsh shifts or anything negative when running higher than factory-spec AFL pressure.



TLDR version:
Blocking both 3-2 won't hurt anything. It cures leaks. Lets builder use "band release" hole to control the downshift timing to their desired feel
Leave AFL balance hole alone OR drill .078 if it makes you feel better. No harm, no foul.


p.s. using the purple and yellow spring from the 3-2 downshift valve INSIDE of the factory AFL will do the same as the trangso white spring. It fits the same and has pretty similar spring rate. So if doing a shift kit without transgo...you can use that spring to your advantage for free

 

Thanks for explaining all that, MaroonMonsterLS1, that should help. I tried to find the why for the blocking the 3-2 but could not find much at all so your explanation is great.
I have tried to understand how this tranny works but my brain says STOP IT! YOU ARE KILLING ME!

So I understand more now about the blocking of the 3-2 valves, seems like a no-brainer!
1?? What does "TLDR" version stand for?


2?? What would you recommend for the band release hole size and the 3rd hole size?

The band release [3-2 shift--the hole at the top of the plate] is currently at .093".
PBA recommends drilling the band release to .099"-.101" when using the Corvette 2cd gear servo. And the 3rd hole to max of .120" for a 4WD, ----it is currently at .101" [after replacing the Sonnax 2nd gear servo with a Corvette 2nd gear servo and throwing out the Sonnax 3rd Accumulator check valve] which helped the 2-3 hang up--which now just has an occasional slight hesitation on a light part throttle -------bump--as measured by my head tipping forward during the up shift.

I did check the line pressure after the rebuild and it was good, just would have to find my notes to show. Drilled a hole in the floor board to run the hose through to have the wife record the pressure.

3?? Question? so using the purple and yellow spring and then leaving the AFL hole size factory should be good---correct?

On the AFL----
As per Sonnax, the AFL hole is at .052" now. But with the new plate and the purple and yellow spring leave the hole stock size--correct? I know, same question as #3.

On the TCC----
I did use the Sonnax limiter as per Yank's recommendation.

4?? Just another question, when I ordered valve body gaskets I was sent the updated glued on gaskets on a new plate with built in screens. I have been using the Transgo wire inserts into the stand up screens left over from the shift kit I replaced with the Sonnax Performance kit. So I have a fresh plate to drill. So the question is---how important is it to use a steel check ball to peen the plate holes for the plastic *****? With the gaskets glue on it will make that job tricky?

OR What would you use, metal or plastic check *****?
The plate I got along with the Transgo shift kit using the metal check ***** had sharp peened holes worn in it so I used the original plate in this full rebuild and the plastic Sonnax ***** [2 years ago.]

5?? If I could be so bold and ask another question---
After this last rebuild I ended up with a harsh 3-4 up-shift. Worst in Cruise Control. What is-was happening is when going up hill with a strong head wind or pulling my light camper it would down shift into 3rd, going into 3rd convertor lock up and then at the top of the hill up-shift directly into 4th gear lock up causing a harsh shift. I had my tuner address this and he changed the down shift to keep it in 4th longer before a down shift which helped. Driving with out Cruise control it barely has the harsh shift. All torque management has been removed. The tuner has said he would address then again so there is no problem there but I was wondering if you had any thoughts on this??
The worst part of this is on the highway it is a bad time to find out that the roads are slippery , the back end likes to fish tale!! Which makes the traffic slow way down that is behind me! As I am correcting the fish tailing going down the road at 75-80 MPH! I think this mostly a tune fix but I am just wondering if there is any thing valve body wise I could do.

I hope my questions are not as confusing to you as it is to me!!!
My first rule is understanding how something works before I try to fix, modify or replace. But sadly I break this rule when it comes to automatics.
I have looked at the descriptions-read the book so to speak-- on how the tranny works---------and am still confused.
Thanks for the careful explanation and your time. I will try to understand more before I open up the tranny's valve body.
I have time, I pulled the engine out for a rebuild. Time to reduce the .004" piston clearance, .002" bore tapper and the cold piston knock. And try some different lifters for the lifter tick.
I replaced the right front axle seal and wheel hub. Easy to do when the motor is gone!
And, cleaned the rust spots off of the front of the frame and paint it AGAIN. In ND the beet juice used on the streets for snow and ice loves to eat metal.
Thanks again

 

1.TLDR= "too long didn't read"
2. hole sizing is usually per-application for me. If you have a recommendation from PBA, it's likely spot on.
3. I've had success with Stock AFL spring, purple/yellow 3-2 spring INSIDE stock AFL spring, then the balance hole stock size.
4. I'd use plastic ***** and YES peen the plate. Just set one of your old steel check ***** on the plate, put the plate on a flat workbench, and give it a light blow with a hammer. You don't have to hit it hard.
5. the harsh 4th gear upshift is because the converter is locked. In stock builds I very very often will block 4th accum with a check ball, and drill the feed to .100
As long as the trans doesn't try to shift 3-4 with the converter locked, it feels fine even with blocked accum and large feed. Most truck guys actually prefer it this way.
A tune to only allow lockup in 4th gear will solve the harsh shift and extend the converter clutch life. If you're going to tow in D3, then I can see a case for lockup in 3rd.

 

I sure hate when people do that! There's a lube orifice that feeds the low reverse clutches that's there for extended highway driving in high gear. I've seen distressed LR because of blocking the 4th accumulator case feed. Double stacking two accumulator pistons "Legs to Legs" with some 1/4" washers between them effectively blocks the 4th accumulator without cutting the lube to the LR clutches. Precision "Ring Shims" are avaliable from McMaster-Carr.

Not trying to be a dick, And it wouldn't bother me as much if driving a check ball in the case was easily undone!

 

Drives me nuts too...that's why I leave the guts of the accumulator out.

Then, accum oil still feeds the lube orifice. Except now, that orifice sees oil ALL the time...rather than just in 4th gear.

From the 6 or 7 units I've refreshed, some that I know spin 7k+ rpm, having 4th blocked and leaving all the guts out shows no negative affects at all. Rear geartrain looks nice and pretty.

 

OK, I think I have two of the three mods figured out.
1. Blocking the two 3-2 down shift valves.


2. Putting the removed 3-2 spring into the AFL.


3A. Drilling out the 4th feed hole to .100" letter "E" in the diagram. And removing the spring and piston.


3B. Is where I am confused. So please school me in what I am missing, I am lost when it comes to figure this out.
1. What about the case side check ball? Leave in or take it out?
EDITED PLEASE SEE POST #10 below
[FOUND 3 PORTS] 2. I see two holes in the 4th accumulator bore in the case. I noted which one I think I should block, correct?

[FOUND 3 PORTS] 3. So in the posts above it is mentioned that it will stop the lub flow or not--if one of two is blocked how can any flow be there? And in the diagram it shows 3 ports, one is labeled EX, but I only see two? Is there a joined passage on the back side in which the diagram does not show? In the page diagram there is a small #19 by the EX label on the left side on the accumulator.

4. How will this effect the 3rd shift convertor lockup to 4th gear convertor lockup upshift? Which I am try to soften.
In the diagram it notes that a bad or leaking accumulator can cause a rough upshift. Is not what I am doing?

Thanks again for your patience. Any foul or abusive language with be tolerated.

 

I'm in for more knowledge too.

 

Never thought about leaving the piston out & letting Accumulator oil feed the lube orifice, Thanks.....Even an old dog can learn new tricks!

 

Hello MaroonMonsterLS1,
I am sorry for doubting your instruction, I am so dumb, you must have much patience. The 4th accumulator problem was driving me nuts, so I looked at the schematic and what did I find 3 passageways. #21 is at the top -lip of the bore. Now it makes sense.
So all I need to know now is
1. Do I leave the check ball out of the case?
2. And to double check if this will help the harsh 3rd lockup to 4th convertor lockup shift?
Thanks again

 

[QUOTE=Metalchipper;20257572]OK, I think I have two of the three mods figured out.
1. Blocking the two 3-2 down shift valves.


2. Putting the removed 3-2 spring into the AFL.


3A. Drilling out the 4th feed hole to .100" letter "E" in the diagram. And removing the spring and piston.



[/QUOTE)

1. yes.
-you are helping to control a leak in the 3rd circuit by blocking the 3-2 down-shift valve (it is ideal to use a Sonnax or TransGo "Abuse Valve Plug" in this location).
-You are also gaining greater control of 3rd accumulator oil by blocking the 3-2 control valve (all 3rd Acc. oil now must pass through the #2 check-ball and #12 orifice).

2. is fine... better to perform an AFL ream and valve job on the valve-body

3. is fine.

These are simplified diagrams of some of the hydraulic circuits when shifting up to 3rd gear.

This is with the 3-2 control valve open:

 

Orifice #28 is Third Feed/ Letter A for TransGo.

Orifice #12 is Third Accumulator/ Band release/ Letter G for TransGo.

Orifice #13 is Third Exhaust/ Letter C for TransGo.

 

This is with the 3-2 Control valve closed:



This essentially closes off a path around the check-ball and orifice (shown as a separation in the diagram).

 

UPDATED WITH NEWER DIAGRAM!

Blocking the 3-2 control valve forces the oil to always pass through the check-ball and orifice.
The Fluid Passages that show as Purple, you should consider them to not exist, as Fluid is blocked to the Passage or at the component.
This essentially removes one path from the circuit (the Path through the 3-2 Control Valve).

Like this:

 

2. Putting the removed 3-2 spring into the AFL.




[/QUOTE)

Hello vorteciroc,
Thanks for your reply, I do have the Sonnax Forward and Reverse Abuse Valve kit in, so you are saying that I should leave that in? And not block it?
Then I will have to find another 3-2 spring for the AFL but that is no problem.

Edit, I see now you said "Abuse Valve plug" which I have, so i can still block the 3-2 valve correct?

 

just block it.
it is fine.

 

Thanks, I got it now.

 

Hello vorteciroc,
Any thoughts on blocking the 4th accumulator to help a harsh 3rd convertor lockup to4th gear convertor lock up?
Look at post #10

 

Regarding lock up... Look at the plastic snout of the TCC apply solenoid... it is often found cracked.

 

Looks like you're getting most of it figured out.
1/2/3 you have done just fine. The brake line to block is perfectly fine.

for step 4, you have noted the correct hole to block.

As for shift firmness, this will firm the 3-4 shift. It helps the band live a longer happier life, and helps 4-3 downshifts be nicer also (because you don't have a reverse quasi-accumulator trying to backfeed the band while the oil exhausts)
With that said, blocking 4th has NEVER been too aggressive for any setup I've had. From stock caprice classics, to my fiance' buick rainier (she's picky on shift feel too...probably my fault ha!), camaros, pickups, etc.

The reason your 3-4 shift is SO aggressive is because the converter is locked during that shift. Even a stock setup with accumulator and small feed hole will feel bad because the converter is locked.
If you will be towing in D4 shifter position, have 3rd gear converter lockup tuned out. I think you'll find that mileage will not change, and pulling hills or other areas where a 4-3 downshift needs to be made...you'll like how it tows better because the converter will be able to use the torque multiplication in 3rd to help pull that grade instead of being locked and making the motor do it all by itself. No lockup in 3rd also means that your overly firm shift into 4th will be fixed.