A650e valve Body / shift kit and transmisison thread

[Brad Bedell]

Not sure if anyone else has gotten into these things, I posted this in the IS300 forums, but I know you guys are considerably more curious than the bulk of those guys. I figure I'll open the floor for a discussion to help me get my head around the whole valve body operation.

First things first, the 'shift kits' I've seen out there are pretty simple in design. They use a rod to limit the movement of the Accumulator piston. The only reason an accumulator is used is to absorb the shock of the hydraulic pressure between shifts.

It seems the easiest solution is to use a rod to stop that movement. My concern is that the rods stopping a moving item will eventually wear parts that probably were not designed to be worn. A stainless rod would wear the valve body and accumulator piston. An aluminum rod would eventually wear aluminum to aluminum. Toyota switched from Steel balls in the valve bodies to plastic ones for this reason.

Other ways to accomplish similar results with faster/stiffer shifting would be increasing pressure, raising volume to the accumulators or stiffer springs. Various Toyota models tweak these adjustments as seen below:


Accumulator pistons with limiting rods are shown here: (note the C0 Accumulator has a rod in this shift kit, it's the only one I've seen with it. )

From left to right:
B2: 3rd brake
c2: Direct Clutch
B0: Overdrive brake (which seems to be omitted in some shift kits)
C0: Overdrive Direct Clutch

This is how the GS400 accumulators come stock:

What's interesting is The IS300 C0 accumulator did not have the secondary spring inside as seen here:

My LS430 C2 spring had a helper spring and keeper, it looked like this:

The A340 box has rods in the lower springs also, Makes me think they were trying to close off some of the accumulator volume by limiting that spring:



Toyota also has built in adjustments on the following items:
primary regulator valve: 3 position that tightens the springs about 1mm per click. Shown in pic in the tightest position:

The accumulator control valve:

Release control valve:

The line pressure control solenoid has adjustments on it, as well as the lockup control solenoid. I'll photo these as I get time.


This chart shows what's being used in the gear of choice:

Key:


B0: Overdrive brake (which seems to be omitted in some shift kits)
B1: 3rd Coast Brake
B2: 3rd brake
B3: 2nd Brake
B4: 1st & Reverse Brake
C0: Overdrive Direct Clutch
c1: Forward Clutch
c2: Direct Clutch
F0: Overdrive 1 way Clutch
F1: No. 1 One Way Clutch
F2: No. 2 One Way Clutch

So, regarding accumulators, I'm interpreting that since B0 isn't used for anything in the chart, other than reverse and 5th gear, it's probably not necessary to stick a rod in. Can anyone speak of other shift kits?


I'm still wrapping my head around the whole thing, but I suspect there's quite a bit of tweaking available without even messing with the accumulators.


Anyone have any corrections as to the info I've shown or input from experience? Ideally, I'd like to not share in public the rod lengths from various kit builders. It's just bad form and they help us out from time to time. I do have the T274 TIS Toyota Training manual in PDF form. It goes over the A750 box, but Auto Transmissions are all similar in design. I'd like to find one of the earlier courses that covers the A650.


Reference threads that I've found, regarding the A340 transmission that have good info are here:
Tranny tech said "don't do VB upgrade" - CustomTacos.com Forum
MK3 TSRM On-Line
How to make a a340 last(56kers take a nap) - Supraforums.com
Modding the A340LE transmission - PerformanceForums

 

[Brad Bedell]

I'm using this post for questions/concernts that I'm still working on:

Anyone have any corrections as to the info I've shown or input from experience? Ideally, I'd like to not share in public the rod lengths from various kit builders. It's just bad form and they help us out from time to time. I do have the T274 TIS Toyota Training manual in PDF form. It goes over the A750 box, but Auto Transmissions are all similar in design. I'd like to find one of the earlier courses that covers the A650.

Why does B0 accumulator have a rod in some shift kits and not in others (340 series). I suspect it's not necessary unless you're really trying to boost in 5th gear. I need to see where 5th hits on my car, but I suspect I'm well into the triple digits by then. What I'm mostly concerned about is the timing of this accumulator. What happens if I soften B0 and when c1 and B2 don't have the same timing when going into 5th gear.

When adjusting the valves that Toyota designed into the transmissions, what does the primary and accumulator control valves do specifically with the 'shifting'.

 

[Brad Bedell]

Just reserving this one in the event I need more space in the future.

 

[jibbby]

Brad Bedell this is an interesting thread you started with outstanding pics... Apparently you know what you are doing and I don't... I just want to say I appreciate this thread so far, as I've never really had a chance to see how the inside of auto tranny looks and works.......

If I were to try taking that tranny apart like you did I guarantee it would never operate the same again after I put it back together.....:33:

 

[Brad Bedell]

Thanks Jibby, but I'm just fumbling through it... I'm more dangerous than I am good at this point. To repair, is easy enough. Measure specs and make it right. However, to modify it requires a whole other side of the brain. Auto trannys are quite simple in nature but VERY precise and unforgiving to the mechanic with ADD.

If my transmission wasn't a hybrid between the IS300 and GS400, I'd be more into destroying some parts for knowledge. However, to replace it requires me to completely disassemble a GS box and reassemble it with the IS300 tail shaft assembly... It was quite an undertaking. Not a simple swap the box out.

With that being said, if anyone wants the repair manual on the transmission or the Toyota automatic transmissions training course, I'd be happy to email it to one person. However, that person needs to be able to host it for me as I don't wish to tie up my mail server more than once.

-B

 

[jibbby]

Well from what I can see so far you have your project under control...

Good luck and perks to you for giving it a go..

 

[kc95sc400]

Brad,

Wondering if you've made on progress on this.

I have an SC400 with an A340E and have already adjusted the regulator and shimmed the accumulators.

If you don't mind, could you elaborate on what the accumulator control valve and the release valve do? And, are they externally adjustable?

Thanks,

KC

 

[Transdude]

Not sure if anyone else has gotten into these things, I posted this in the IS300 forums, but I know you guys are considerably more curious than the bulk of those guys. I figure I'll open the floor for a discussion to help me get my head around the whole valve body operation.

First things first, the 'shift kits' I've seen out there are pretty simple in design. They use a rod to limit the movement of the Accumulator piston. The only reason an accumulator is used is to absorb the shock of the hydraulic pressure between shifts.

It seems the easiest solution is to use a rod to stop that movement. My concern is that the rods stopping a moving item will eventually wear parts that probably were not designed to be worn. A stainless rod would wear the valve body and accumulator piston. An aluminum rod would eventually wear aluminum to aluminum. Toyota switched from Steel balls in the valve bodies to plastic ones for this reason.

Other ways to accomplish similar results with faster/stiffer shifting would be increasing pressure, raising volume to the accumulators or stiffer springs. Various Toyota models tweak these adjustments as seen below:


Accumulator pistons with limiting rods are shown here: (note the C0 Accumulator has a rod in this shift kit, it's the only one I've seen with it. )

From left to right:
B2: 3rd brake
c2: Direct Clutch
B0: Overdrive brake (which seems to be omitted in some shift kits)
C0: Overdrive Direct Clutch

This is how the GS400 accumulators come stock:

What's interesting is The IS300 C0 accumulator did not have the secondary spring inside as seen here:

My LS430 C2 spring had a helper spring and keeper, it looked like this:

The A340 box has rods in the lower springs also, Makes me think they were trying to close off some of the accumulator volume by limiting that spring:



Toyota also has built in adjustments on the following items:
primary regulator valve: 3 position that tightens the springs about 1mm per click. Shown in pic in the tightest position:

The accumulator control valve:

Release control valve:

The line pressure control solenoid has adjustments on it, as well as the lockup control solenoid. I'll photo these as I get time.


This chart shows what's being used in the gear of choice:

Key:


B0: Overdrive brake (which seems to be omitted in some shift kits)
B1: 3rd Coast Brake
B2: 3rd brake
B3: 2nd Brake
B4: 1st & Reverse Brake
C0: Overdrive Direct Clutch
c1: Forward Clutch
c2: Direct Clutch
F0: Overdrive 1 way Clutch
F1: No. 1 One Way Clutch
F2: No. 2 One Way Clutch

So, regarding accumulators, I'm interpreting that since B0 isn't used for anything in the chart, other than reverse and 5th gear, it's probably not necessary to stick a rod in. Can anyone speak of other shift kits?


I'm still wrapping my head around the whole thing, but I suspect there's quite a bit of tweaking available without even messing with the accumulators.


Anyone have any corrections as to the info I've shown or input from experience? Ideally, I'd like to not share in public the rod lengths from various kit builders. It's just bad form and they help us out from time to time. I do have the T274 TIS Toyota Training manual in PDF form. It goes over the A750 box, but Auto Transmissions are all similar in design. I'd like to find one of the earlier courses that covers the A650.


Reference threads that I've found, regarding the A340 transmission that have good info are here:
Tranny tech said "don't do VB upgrade" - CustomTacos.com Forum
MK3 TSRM On-Line
How to make a a340 last(56kers take a nap) - Supraforums.com
Modding the A340LE transmission - PerformanceForums

Seems that the first picture is from my website. Sorry to get your hopes up but there are no 'blocker' rods there.

Those are just studs that I screwed into the trans case to take pictures for my instruction sheet. The case was face-up on my bench so I held them in place with the studs and afterward rotated the pic in Photoshop.

If anyone wants info on what's involved with properly modifying the valve body, I can post some from an article that I wrote on the subject a while back.

-John

 

[kc95sc400]

If anyone wants info on what's involved with properly modifying the valve body, I can post some from an article that I wrote on the subject a while back.

I for one would absolutely love to see the article. I'm suprised you'd share the info.

I have a supercharged 95 SC400, which actually has a 96 SC400 transmission in it. I have shimmed the accumulators (pretty near completely blocked off), adjusted the pressure via both the regulator screw and the throttle cable. Also should mention the dragon tc with 2800rpm stall, multiple fluid coolers and a disabled no 4 solenoid.

Running 8.0 to 8.2 1/8 mile times with 350ish rwhp. I was bouncing off the rev limiter very badly with my original trans which I did the above modifications to after boosting on it for a year daily driving and 80+ track runs.

I modified the 96 trans before putting it in and it will still bounce 1-2 times with WOT before it shifts to second but it is a million times better. I would love for it to not bounce at all.

Any info / clues you could provide would be awesome!

KC

 

[Transdude]

I for one would absolutely love to see the article. I'm suprised you'd share the info.

I have a supercharged 95 SC400, which actually has a 96 SC400 transmission in it. I have shimmed the accumulators (pretty near completely blocked off), adjusted the pressure via both the regulator screw and the throttle cable. Also should mention the dragon tc with 2800rpm stall, multiple fluid coolers and a disabled no 4 solenoid.

Running 8.0 to 8.2 1/8 mile times with 350ish rwhp. I was bouncing off the rev limiter very badly with my original trans which I did the above modifications to after boosting on it for a year daily driving and 80+ track runs.

I modified the 96 trans before putting it in and it will still bounce 1-2 times with WOT before it shifts to second but it is a million times better. I would love for it to not bounce at all.

Any info / clues you could provide would be awesome!

KC

One can pull out their own teeth but it is usually better to go to a dentist.

There is much more to correctly modifying a valve body than shimming accumulators. That said, here is the article.

As many Toyota and Jeep owners know, the AW4 / Toyota 340, A340, and A341E series of transmissions are generally very well made and demonstrate excellent durability in unmodified applications. The framework is present for an extremely strong transmission that is to be used in a high performance or extreme duty application. The problem is that the original calibration is engineered for driver comfort rather than ultimate component strength. The soft, sliding shifts that are part of the original design are not appropriate for increased horsepower applications, towing, off road use, racing, etc.

These calibration inadequacies quickly manifest themselves as extremely poor shift quality, and more often than not, severe damage to the gearbox is soon to follow. One of the most common symptoms of this is the engine stuttering or hitting the rev limiter during a full throttle upshift. Without going into too much technical detail, the factory shortcomings can be addressed through modification and recalibration of the control valve assembly, a.k.a. the valve body.

The valve body is a component that is comprised of valves, solenoids, an orifice separator plate and an intricate series of passages- it is the most complex component in the most complex part of your vehicle- the automatic transmission.

The function of the valve body is to act as the "brain" of the automatic transmission- it directs hydraulic pressure to the appropriate clutches and bands at the right time to initiate upshifts, down shifts, selection of reverse, converter clutch application, etc. As well as controlling shift timing and shift quality, it is also responsible for directing hydraulic pressure to the cooler and the lubrication circuit. As you can imagine, the transmission's operational characteristics can be drastically altered and also customized to the given application through modifications to this component.

Because there are no commercially available shift kits for these transmissions, we began working on valve body modifications that were appropriate for Supras, Jeeps with the AW4 transmission, Toyota Tundra, Tacoma and 4Runner, and also Lexus SUV's and rear drive passenger cars- especially those that needed to handle the additional power that accompanies the installation of a supercharger, turbo or nitrous oxide injection.

At the risk of oversimplification, there are a few things that are done in concert to create much more favorable operation of the gearbox. The first thing that needs to be done is to increase the hydraulic operating pressure of the transmission- this pressure is known as "line pressure". All hydraulic functions of the transmission are based on this pressure- what is especially of concern for these purposes is the clamping force which is applied to the clutches and bands to get them to hold against engine torque.

In simple terms, increased engine output is complemented by increased line pressure and increased "clamp" on the clutches- this can be likened to a performance clutch with a heavier pressure plate spring in a manual transmission equipped vehicle. The idea is to raise this pressure only slightly at light throttle but increase it by 30-40% at full throttle- where it is really needed.

The effects of this are shifts that are not overly uncomfortable at lower throttle openings, while at heavier throttle, firm shifts with much shorter clutch application time and increased clamping force can be achieved. An additional benefit of this is increased flow through the transmission's cooler and lube system.

Secondly, hydraulic pressure is normally routed through an orifice in a metal "separator plate" that resides between the two halves of the valve body before it gets to its intended destination. By altering these orifices, we can increase the volume of hydraulic oil that is used to apply the various clutches and bands.

The final part of modification is the alteration of the accumulator circuits. These are hydraulic circuits that are parallel to the components that are used for shifting. Their function is to absorb or "accumulate" some of the hydraulic pressure that is intended to apply a clutch pack or band. By limiting the action of what is essentially a "shock absorber" for each shift, we are able to further reduce clutch lock up time and shift lag at wide open throttle.

The end result is that shift time is reduced by 30 to 80%, depending on the amount of acceptable shift feel and the intended application. The clamping force that is required to apply the clutches and bands is increased by 30 to 40% at full throttle. Flow through the cooler and lube circuit is increased and the converter clutch application time is also reduced.

Transmission and valve body upgrades are not only for American made vehicles anymore. Increased performance and more efficient shifting is now available for vehicles of almost every manufacturer thanks to the few companies that are willing to do the research and development work required for this rapidly growing segment of the automotive aftermarket.




----------------------------------------------------------------------------------------------------------------------------------------------
John Lombardo is owner of IPT Performance Transmissions and has been in the transmission and high performance industry for over 22 years.

 

[kc95sc400]

So, how much do you charge for a “proper” modification job? PM me.

I have seen that article before.

I know that there is more involved to it than stiffer springs / shims, the problem is knowing what else to do. Having the know how is what allows you to modify the valve bodies at a cost. I do completely respect that, I am actually a Toyota technician and I know all about getting paid for knowledge when it comes to working on cars.

But I have to be honest, it’s frustrating to me. I have a general idea (at least I think I do) of how the valve body works. Have some ideas on what could be modified to improve shifting. I’m assuming there are a few holes to be drilled larger. I would also think good things would come from changing out the springs for the shift valves. I would guess that enlarging the actual fluid passages isn’t needed. Again, it all comes down to knowledge…..I’m fairly sure I could make the modifications myself but without truly understanding the complexities of the valve body, I wouldn’t really know where to start.

Now that being said, turning the adjuster screw to increase pressure and shimming the accumulators alone have very much improved the shifting in my transmission. Shifts quick and firm (but not uncomfortable) for normal driving. TC lockup almost feels like a 5th gear engaging. It shifts so hard into 3rd at WOT it shakes the whole car a bit. The only problem I still have is 1 or 2 hits on the limiter before it shifts to 2nd at WOT.

I would also like to say that in my opinion, disabling the no 4 solenoid is a must.

I’m on my second box now but I really think the first one died because it took me so long to do anything about it. I never really even took it into consideration until it was already bouncing on the limiter, only then did I modify it. Helped for a while but then it quickly got worse. The box I have in now was installed with half the mileage on it and was modified before I put it in. I should also note that I had 80 or more track runs on the original box.

Sorry to be so long winded, PM me a price please.

If you don't mind, a question. Is there any reason I can't use dex instead of t4?

KC

 

[Transdude]

So, how much do you charge for a “proper” modification job? PM me.

I have seen that article before.

I know that there is more involved to it than stiffer springs / shims, the problem is knowing what else to do. Having the know how is what allows you to modify the valve bodies at a cost. I do completely respect that, I am actually a Toyota technician and I know all about getting paid for knowledge when it comes to working on cars.

But I have to be honest, it’s frustrating to me. I have a general idea (at least I think I do) of how the valve body works. Have some ideas on what could be modified to improve shifting. I’m assuming there are a few holes to be drilled larger. I would also think good things would come from changing out the springs for the shift valves. I would guess that enlarging the actual fluid passages isn’t needed. Again, it all comes down to knowledge…..I’m fairly sure I could make the modifications myself but without truly understanding the complexities of the valve body, I wouldn’t really know where to start.

Now that being said, turning the adjuster screw to increase pressure and shimming the accumulators alone have very much improved the shifting in my transmission. Shifts quick and firm (but not uncomfortable) for normal driving. TC lockup almost feels like a 5th gear engaging. It shifts so hard into 3rd at WOT it shakes the whole car a bit. The only problem I still have is 1 or 2 hits on the limiter before it shifts to 2nd at WOT.

I would also like to say that in my opinion, disabling the no 4 solenoid is a must.

I’m on my second box now but I really think the first one died because it took me so long to do anything about it. I never really even took it into consideration until it was already bouncing on the limiter, only then did I modify it. Helped for a while but then it quickly got worse. The box I have in now was installed with half the mileage on it and was modified before I put it in. I should also note that I had 80 or more track runs on the original box.

Sorry to be so long winded, PM me a price please.

If you don't mind, a question. Is there any reason I can't use dex instead of t4?

KC

We change about 9 springs, drill several holes, change sleeves and valves (depenidng on exactly what valve body configuration we are working on).

No offense, but just shimming accumulators and testing the results by "seat of the pants" shift feel comes nowhere close to cutting it.

This is why there are plenty of transmission shops use us to do the modifications. Although they work on transmissions for a living, they recognize that doing these types of modifications are outside of their area of expertise.

As far as info and pricing- it is located here:
IPT Toyota Performance Transmissionshttp://www.importperformancetrans.com/toyotaauto.shtml

-John

 

[kc95sc400]

Please, don't get offended. As I said, I know (and respect the fact) that knowledge here is power (and money) and I might very well need your services in the future.

The only reason I have a tone of frustration is because of the fact that I know I could do the modification myself if I knew where to drill, what springs to change, ect. Seems to me the hardest part of the whole thing is removing the valve body from the trans to begin with. I've never split a valve body into its two halve but it really doesn't seem like a big deal to me.

As far as the seat of the pants test....these mods have also taken 4 tenths or more (don't have the numbers in front of me) off my 1/8 mile times. This good proof of the difference the simple mods can make. You have to admit that the few little things I've managed to do are better than nothing.

KC

 

[minty uk]

hi transdude , i have an ipt modified valve body in my car , its the one that you recently sent to england , the shifting is very fast and the car chirps the tyres when shifting , i am very pleased with this mod . currently i am using the standard type 4 transmission fluid can i use royal purple ? . the valve body from my sons car will be coming out to you after xmas .

 

[Transdude]

hi transdude , i have an ipt modified valve body in my car , its the one that you recently sent to england , the shifting is very fast and the car chirps the tyres when shifting , i am very pleased with this mod . currently i am using the standard type 4 transmission fluid can i use royal purple ? . the valve body from my sons car will be coming out to you after xmas .

Hi,

I'm glad to hear that your are happy with the work.

I use and recommend our own blend of ATF as well as Amsoil Universal Synthetic ATF, but feel that any synthetic Dex III type of fluid would well also.

-John

 

[Transdude]

Please, don't get offended. As I said, I know (and respect the fact) that knowledge here is power (and money) and I might very well need your services in the future.

The only reason I have a tone of frustration is because of the fact that I know I could do the modification myself if I knew where to drill, what springs to change, ect. Seems to me the hardest part of the whole thing is removing the valve body from the trans to begin with. I've never split a valve body into its two halve but it really doesn't seem like a big deal to me.

As far as the seat of the pants test....these mods have also taken 4 tenths or more (don't have the numbers in front of me) off my 1/8 mile times. This good proof of the difference the simple mods can make. You have to admit that the few little things I've managed to do are better than nothing.

KC

As you can imagine, everything in a valve body mod is a coordinated system. Getting it right involves a lot of transmission experience, knowing exactly how they work, some math, extensive in-vehicle testing and a lot of valve bodies getting R&R'ed for additional tuning.

As far as a claim of an over four tenths in 1/8 mile ET reduction from valve body mods alone, you must have reinvented the wheel, that's the equivalent of adding 60-80 horsepower.

Have you quantified these improvements scientifically, i.e., swapped a valve body while at the track on the same day etc.?

I have been doing this since 1987 with all types of transmissions and it is pretty rare to see anything really measurable in a timeslip from a valve body mod. alone with no other changes. I have, however, seen some disreputable companies make these types of claims but we certainly don't (won't mention names here).

-John

 

[Fasteddie]

Transdude,

since we are on a V8 forum: will those modified IPT A340e/A650e boxes survive the torque delivered from a built Lexus 4.0 V8 ?
I am thinking of a built block with 600 rwhp and 800+ ft/lbs....
And if not, what will kill it?...excessive heat ?

thx !

 

[Transdude]

Transdude,

since we are on a V8 forum: will those modified IPT A340e/A650e boxes survive the torque delivered from a built Lexus 4.0 V8 ?
I am thinking of a built block with 600 rwhp and 800+ ft/lbs....
And if not, what will kill it?...excessive heat ?

thx !

We have 340's out there with higher power levels than that for sure. As far as the 650's go, that would be approaching their limit.

-John

 

[Arnout]

John
I tried to contact you at the shop twice today but missed you. I was wondering if you know in what way the shift solenoids are controlled on the A650E. I'm having a hard time controlling the transmission, somehow it doesn't shift from 1 to 2. The seller (PF Supercars) said that you have to PWM the shift solenoid signal and not On/Off like the A340E. Do you know anything about this?

regards
Arnout

 

[stevechumo]

John,
With a valve body that you modified for the A341E or A340E, do you think it'll hold up the tranny up to around 400 rwhp and rwtq? How much does it cost to have you modified it? You may P.M. me. Thanks.