Dave3891

Does the 4L80E have engine braking (Overrun clutch?) in all gears when shifted with the solenoids electrically?

I currently have a 4L60 with a paddle shift controller that I made, it works well but the 4L60 doesn't have engine braking when the selector is in D and the solenoids are shifted with the controller.

I saw that TCI makes a valve body that would allow this on the 60E but I would prefer to just get a stock 4L80E (stronger) if it already has an engine braking when electronically shifted configuration.

Ratdaddy60

The 4L80E only has engine braking when shifted manually. The overrun clutches only engage in manual 1st,2nd, and 3rd gears.

pjwollman

I spoke to tech at Sonnax last week and their smart tech clutch over run kit or valve body with the preinstalled overrun kit is supposed to allow for engine braking with electronic shift (bump shift mode). I would like to confirm this again because I am about to remove my TCI 6x and install a built 4L80e and it is because the 6x will not do engine braking in electronic shift mode which defeats its whole purpose for me. I need engine braking and I want it to be used with my new Lokar sport mode shifter so I can electronically bump shift and engine brake through corners.

https://www.sonnax.com/parts/4496-sm...utch-valve-kit

pjwollman

I spoke to Sonnax again and this time spoke to the R&D department (really good people) and they spent a lot of time with me. The bottom line is, No Engine Braking in electronic bump shift mode is available with the 4L80e. The best bet at this time is to use their kit and a ratchet shifter whereby you are manually clicking down into L1, L2, and L3 as mentioned above by ratdaddy60. Sonnax certainly was thinking through the possibilities and what it would take to build a kit, but there would have to be a large demand. On a side note, I wonder how PCS managed to pull off electronically bump shift and engine braking with their 5/6speed valve body and controller when it was on the market?

MaroonMonsterLS1

You CAN have engine braking, even when in D4, if the right things are done to modify the valve body and the rest of the trans.

Sonnax doesn't offer anything. I'm not sure anybody that does to the public. But It's possible.

For engine braking, here's what you need.
Overrun clutches for all gears except 4th. This can be accomplished with the sonnax kit.

1st gear needs the rear band. This is not applied in stock form unless in D1
2nd gear needs the front band. This is not applied in stock form unless in D2
3rd gear has engine braking by default AS LONG AS the overruns are applied

You can modify as needed to get all of these components to apply in D4 but it's not easy and there are no kits or (as far as I know) valve body options available to just order

pjwollman

Thanks, well I guess it maybe best for me to pull the TCI 6X and get a purpose built 4L80e and run it with a ratchet shifter, if I want to stay with the automatic and have true engine braking this seem like the only way to go.

Do you have any recommendations about the best transmission builder, I doubt TCI will build a 4L80e with the Sonnax Kit or Valve body?

5.7stroker

iTrader: (36)

MaroonMonsterLS1 is one of the best transmission builders out there. He helped me build mine by answering many of my dumb questions and I didn't even know what the hell I was doing most of the time lol

pjwollman

In my never-ending quest to answer/understand the 4L80e electronic engine braking dilemma, I came across this post on the Yellowbullet site https://www.yellowbullet.com/threads...aking.2631725/ Jake said the following 11 months ago:I've made a VB that has engine braking in each gear with the shifter in D3. So you can have electronic control of upshifts and downshifts and have engine braking in low and 2nd. Might be able to combine it with the Sonnax deal and leave it in OD. I haven't looked. www.jakesperformance.com Racing GM Automatics 4L80Experts
Jake, does this mean that I can finally use myLokar Automatic Electronic Sport Mode Shifter and obtain electronic shifting with engine braking by using your "new valve body"? I am using the Lokar shifter on a TCI 6x transmission which I have had my share of issues with, but my biggest complaint was no electronic engine braking as many of you know, and I am not crazy about the multitude of gear split shifts either. So, if I am now able to run the 6x and turn it into a 4 speed with a new valve body and have an electronic shifting with engine braking, I would be satisfied. Currently, with my Lokar Shifter it will slip over into the electronic Bump Shift Mode from the overdrive position, so I would need to modify it, if possible, to do the same from D3 based on Jake's above-mentioned description.

truckdoug

iTrader: (25)

shoot jake an email. he still handles 99% of their tech emails. its on his website as thier main email.

pjwollman

After a discussion with Mike at Jake's Company, he says Jake does have an upcoming valve body "new product" that will have engine braking in L1 - L2 - L3 with electronic (bump shifting) when the shifter is placed in L-3, and also in all gears in auto-shift mode, as far as I can understand. Although I assume OD won't have engine braking. Evidently, he does have a prototype of this VB running in a few cars and trucks and is now perfecting it, but it's not cheap to buy from him.

In my case, it sounds like a good VB and would take care of the lack of engine braking and make the 6x function correctly (as a 4 speed except for the different gear ratios) I also would hope that the painfully hard 3 gear shift in the 6x would be eliminated. BTW, Lokar will modify my shifter to use the L-3 slot for the bump shift mode rather than the current OD position.

On another thread, MaroonMonsterLS1 said there is no problem converting the TCI 6x back to a 4 speed with a correct VB. Below is a link in which a guy tore down the 6x to see what modifications TCI made. There are pictures that show the TCI mods. However, some concerning statements in the link are as follows; "Case modified to accommodate the bigger bolt. The center seal has been removed from direct clutch drum and the reverse feed has been blocked on the spacer plate. The PDF is of the spacer plate holes that are blocked off". If any of the experts like MaroonMonsterLS1 has any last concerns about switching out the VB I would appreciate hearing them before going down this road which is expensive and will void my TCI warranty.

Again, thanks for all your help (yes I know I shouldn't have bought the 6x)

https://www.hotrodders.com/threads/6...-4l80e.285594/

MaroonMonsterLS1

The bolt being enlarged just means you need to reuse the bolt that comes out of the trans. Not the end of the world

The center sealing ring being left off is pretty typical.

The separator plate won't matter because you'll replace it when you replace the valve body

Don't remember where you're from but if it's close to me I'd be happy to help you with a VB swap and could put a *normal* gearset back in if you wanted

pjwollman

If the center bolt is larger will the bolt hole in the VB need to be enlarged? On the Hotrodder's thread he said "center bolt hole is enlarged from a 4.1mm to a 4.8mm hole".

So assuming the bolt is slightly larger, will it have any effect on the new VB 's performance?

Currently under WOT at high RPM I feel like my driveline is going get ripped out of the car..... TCI says this is normal with this transmission, I cannot see how they can say that. I assume that TCI did leave out the third feed check ball (I don't know why) and that is what causes the brutal 3 gear shift, with the new VM and check all check ***** installed the shifts should be more normal, correct?

I wish I was closer to your place of business, but I am out in CA. The whole purpose of replacing the VB is get the 6X to operate more normal and have engine braking, and not to take the trans out of my 71 Camaro RS, unless I go another direction entirely. I spent a huge amount of time fitting that transmission in the car, so doing an R&R isn’t what I have in mind right now. If Jakes VM is going to work the way he said it will work, I may just live with the 2.97 first gear ratio and my 3.42 rear ratio. I don't like the RPM drop first to second, but it is no worse than the 4l60e.

BTW, have you ever thought about offering a service to revise TCI's 6X valve body and make it have engine braking and fix up the shifting issues? I know you said it could be done, and there has to be others like me that have the 6X and are not happy with it.

vorteciroc

I am assuming that you are asking about the Bolt that goes into the Center-Support...
If so, the Bolt only goes through the Case, and not the Valve-Body.

The Fluid that passes through the center of that Bolt is Intermediate-Clutch Fluid.
This is for applying 2nd-Gear.

If the ID of the passage inside the Bolt is larger, it might make a minuscule difference in apply time.
It wouldn't really matter.

If your Transmission is shifting overly-firm...
I would replace the Separator-Plate and install all Check-*****.
Fast, Firm, Positive Shifts are what you should want from the Transmission.
Excessively harsh Shifts will only increase wear and tear until something breaks.

The original Gear-Sets are plentiful and good-used Sets are cheap.
I would go that route if you can.

I currently have an Aux. Valve-Body (not much different than what Sonnax produces), and Tubing, with a Solenoid that operates the Overrun-Clutch.
I am in the final process of adding the two needed Circuits into Gen-IV PCMs.
I will have a Daughter-Board professionally Printed that gets soldered on to the PCM Mother-Board.

When that is done, I have to decide who I am going to sell the designs to...
I do NOT want to sell to TCI, but they were the most interested party that I spoke with.
I do not want to do it on my own... I am too busy as it is.

MaroonMonsterLS1

it's the 4th clutch bolt that is enlarged
it's a screw up

he can't just change the separator plate...because this is a 6x and it uses a special plate

applying the overruns will give you engine braking in 3rd, but not 1st or 2nd.
1st needs the low band
2nd needs the intermediate band

OP wants engine braking for all gears, in D shifter position, preferably paddle shifted.

vorteciroc

Thanks for clarifying...
I should have read through the Thread, instead of just making assumptions.

It's good to see you back Grady!

Hopefully you got some good R&R time on vacation.
It is far too easy to get burnt-out, when working in this field.

pjwollman

Grady, remember I am not very knowable about automatics….

• So are you telling me I cannot replace the Separated Plate with a standard one and put the origin Check ***** back in with the new Valve Body?
• If I cannot change out the separator plate then wouldn't that make the new valve body function incorrectly?
• The techs at TCI told me that I could put a standard valve body in the 6x and it would run as a 4 speed, but that was in an effort to keep me from returning the transmission (for whatever its worth).
• The whole idea of using Jakes new VB is to be able to shift my modify Lokar electronic sport mode shifter and put it into D3 and then sideways into bump mode, which will function like a paddle shifter, but with a stick.
• I still don't understand 4th clutch bolt enlargement, so it has nothing to do with the valve body or does it?

Lastly, I wanted to mention that I am using the EZ TCU and the techs at TCI told me I could run the 6x in the standard 4L80E program mode and that it would run as a 4 speed; however it does not shift into OD when I do that. The techs say it should run that way, but it does not and they don't know why. My thought is that it because they use the extra solenoid to shift into OD with the 6x program function, which doesn't work with the 4L80E program function. This issue should be eliminated with a standard VB and a standard harness.

Sorry guys for all of this, but I hope this long thread helps others.

jakeshoe

iTrader: (14)

I sat down and looked at this VB again today.
We're going to do one that allows shifter in D4 position, engine braking in all gears, electronically commanded.
So each band on in 1st and 2nd respectively.
I will machine a couple of valve bodies when I get some time.

MaroonMonsterLS1

If you swap the whole valve body, you will have to run a new separator plate with it.
I was saying you can't just keep the 6x valve body and slap a new stock separator plate on it...that would not work

pjwollman

Ok Jake, that sounds good, so I will call next week and see what your schedule is like. It seems, as if, you now have the R&D done and will go into limited production. You are one of the few to accomplish this in D4 as most have said you cannot have engine braking without pulling the shifter manually into D-3,2, or 1. This is great for me as that was the whole purpose for buying the Lokar sport mode shifter. I am sure many people will be interested in this VB!