Ive seen a few people do this and i dont know why im always open to new stuff on the 4l60e ive build lots stock and mod but why would you leave the over run clutch check ball out

 

I apologize as I am short on time at the moment...

I am only replying because no one else has yet.

The simple answer is that doing so helps prolong the transmission life.
Particularly; the 3-4 clutch pack, the sprag for 3rd gear, and the over-run clutch pack.

If no one else chimes in/ replies... Then I will post again when I have more time...
and provide a better more detailed answer.

 

The first thing to understand is what these check ***** do - when a clutch circuit is activated, the checkball closes and forces fluid through a smaller hole to control how quickly the clutch applies. Then when the clutch circuit is released, the checkball opens to allow the clutch to disengage quickly. You probably know that people drill the separator plate to make shifts firmer and quicker by allowing more fluid to the clutch. Well, removing the checkball is equivalent to drilling a really big hole for that circuit.

So, removing the checkball for the overrun clutch is going to let that clutch apply very quickly. That will reduce the strain on the forward sprag.
Darn, I certainly do not have the experience and knowledge to disagree with vorteciroc, but before he posted, I had the opposite opinion - by allowing max fluid to the overrun clutch when shifting to third gear (with the shifter in D3), the 3rd clutch would be deprived of fluid and could start slipping. This is one reason the Sonnax HD 2-3 Shift valve was designed - to keep the overrun clutch applied in all gears while in D3 so that the 3rd clutch is not deprived of fluid first going to the overrun clutch. Note: this was my prior OPINION and it may be completely or partially wrong.

Therefore, I look forward to vorteciroc's much more knowledgeable explanation. (He is/was a GM transmission engineer.)

 

I have no doubts that you are already familiar with what I have added. Also I am sure all of our regular guys here in the forum are also...
The forum has just been a bit quiet recently.

 

cant find my ATSG manual at the moment....is the check ball being referred to the one(s) in the VB ?

so in order to do a successful check ball removal mod.....what is needed to be done ?

 

There is quite a lot!
Searching our forum will bring up most all of the modifications needed.
From shift-kits, to individual parts like the Sonnax 2-3 valve and O-ring end-plugs...

Honestly, from both an internal leak and a performance standpoint...
The 4L60E valve-body (and circuits in general) are really bad.

Thinking back on this; I am shocked that the 4L60E became the worlds most common RWD electronic 4-speed automatic.

I wish the THM200-4R was updated to a modern transmission instead of the THM700-R4.
But GM is "El Cheapo Company" and decided to update the less expensive THM700-R4 instead.

 

Yes, the #6 check-ball.

The only check-ball to go on the case-side of the separator plate is for the 4th accumulator (there is also two check-ball capsules, low-reverse and 3rd accumulator).

Most builders remove the ball from the capsule (keeping the capsule) for low-reverse. Most builders also delete the 4th accumulator portion of the accumulator circuits.
I remove the low-reverse check-ball from the capsule. However in most cases, I also remove the 4th accumulator ball, but keep the circuit active with piston and springs.
The only thing on the case side of the separator plate for me; is the 3rd accumulator check-ball capsule, (I make some big changes to the 3rd accumulator circuit) and just a dual-spring and pin-less piston for the 4th accumulator.

The list of hydraulic circuit modifications for the 4L60E is very extensive...
I would do some serious searching or hope some of the other members chime in.
Unfortunately the forum has been really quiet recently.

 

Just to add to the conversation being had above by vortec and mrvedit...Removing the checkball for the overrun clutch orifice can be good or can be bad depending on the situation at hand.

I'm in agreeance with mrvedit that under full load, in d3, with an otherwise stock valve body, removing the checkball is a bad thing. Really, the design as a whole is a bad design. GM has the overrun clutch being fed only in 3rd gear when shifter is in D3. Just sillyness. but...since that's the way it is, on a 2-3 shift, the volume needed to fill the overrun clutch acts like an extra accumulator.

So, in D3 on a 2-3 shift, you have LOTS happening inside the 4l60e. The backside of the 2nd gear servo is filling with oil. 3rd gear oil has to "push off" the band and let it release. At the same time, the 3/4 clutches need to apply which means filling up the volume in the piston, AND now the overruns need to apply needing to fill the volume in that piston.

Think of "filling the piston" or the volume needed during the shift like filling buckets with a garden hose. That hose (our transmission pump) can only move so much liquid. If you split that hose up and try to fill 3 buckets at once, it's going to take longer .Same thing with the transmission...taking longer to fill means more slippage and nobody wants that.
Also, imagine now you split that hose and then have individual valves on each end. You can open and close them to your liking. (These valves are the orifice holes in the separator plate) If you have the valve barely open for the 3rd clutch bucket, but you have the valve wide open for the overrun clutch bucket (aka remove the check ball) then the overrun bucket will fill first...exaggerating the problem EVEN MORE and now the 3/4 clutches take even longer to "come on"

If using the sonnax HD 2-3 shift valve, (mrvedit called it the HD 1-2 in his above comments...it's actually the 2-3) you apply the overruns before you're ever moving when the shifter is in D3. You've now eliminated a "bucket" needing to be filled during the 2-3 shift.
Leaving the checkball out will ensure that the overruns receive maximum apply volume and pressure...if there are circuit leaks and you have a small orifice, the leaks may be too large and the orifice will not have enough volume to actually build any pressure and effectively apply the clutch


quick summary
removing the checkball on stock valve body...bad
Removing the checkball on a valve body with Sonnax HD2-3 valve...good.

 

Is the check ball marked in blue the one being talked about or both of those in that location (overrun clutch control, overrun clutch feed)

 

NOT the one in blue. That's called the "bathtub" and it needs to stay

It's the one right next to the bathtub

 

Thanks vorteciroc and MaroonMonsterLS1 for the info. I will try this the next time I do a hi-pro build.

 

@mrvedit take this down if if violated some sponsor rules. (I'm not trying to sell them here right now!) But I have been considering getting some separator plates cut for the 60e that will do quite alot for the home builder and pro alike. I plan for it to do the following:
-Engage the overrun clutch anytime in D3. All gears. No need for the sonnax HD 2-3 Shift valve
-Block the 4th accumulator. I've found this to be a VERY good upgrade on any performance build
-Make the TCC on/off only.
-correct shift timing with proper orifice dimensions

Yes, it will just take a separator plate to do that stuff. (You'll still need to fix all of the leaks that are inherent to the valve body, but the separator plate would be an easy bolt-on upgrade for any trans build

Is that something guys would be interested in? @bbond105 @vorteciroc @98CayenneT/A @PBA etc etc there's loads of guys I could tag so don't feel left out if I didn't write ya down

 

Yes I would be very interested in something like that and would give it a try. PM me if you have a prototype available or when you are ready to go forward with them.

 

Very interested here also. Especially since I will be starting a build pretty soon here due to a driveline failure at my road course event last year that absolutley murdered my transmission. Actually just picked up a 4wd unit from a 2003 Tahoe for the case and hard parts, planet's, sun gear ect......

So yes, I'm absolutely game.

 

see....now i just have more questions !

so sonnax valve and chek B ( i luv how you cant say B A L L S ) removal....good ...or just indifferent ? meaning it does not affect anything.....and you just mention if the tranny is in D3....what if in D4 ....still good?

and a already modded plate would be a time saver

 

In D4 the overrun clutch is never activated and you will therefore put more stress on the forward sprag. Better to let the sprag and overrun clutch share the load, especially with a performance enhanced engine.

 

I am interested. This might be a time saver for me, i am not sure.
I have laser-cut separator plates made for the shop... but I make them universal, and have to plug holes and drill holes depending on what the build entails.

I do not buy very much from Sonnax any more...
I hate to say it... But I machine my own parts in the shop that more or less do the same as some of the Sonnax parts.

O-Ringed end-plugs are by far the thing I make the most of for the 4L60E.

As I said in an earlier post... These modifications really should be performed as a complete system.
Picking and choosing hydraulic changes can make things worse.

 

Damn that implies you know very well the location of every circuit in the valve body. Do you therefore ever have dreams where you are running in a maze and you can't get out? Or a valve crushes your leg? Or crushes your head and you wake up?

 

LOL He probably does.

MaroonMonster is a sharp guy, (Has a degree in Mechanical Engineering) who is self taught when it comes to automatic transmissions.
He reminds me a lot of myself at a slightly younger age... the kind of guy who can essentially learn anything that he wants to.
I have completely wasted all of my degrees... I hope MaroonMonster does not also.

When I opened my business, I had many of the Hydra-Matic complete circuit diagrams enlarged to 4 foot by 16 foot images across 2 sheets of ply-wood and covered by plexi-glass.
They are still on the walls... So that the guys do NOT ruin my last few MINT-CONDITION Hydra-Matic books with ATF finger-prints and filthy stains.

 

It took me a while to figure this out, but I guess you could say check That works for plural anyway not sure how you would say remove one check...