Automatic transmission operation, figuring out how it works

[djkeev]

I have a 1990 2.1 automatic Vanagon GL
I have shifting problems and drivability problems.
Creating this thread is a step to hopefully solving my problems.
I should mention that these problems began after putting on a GoWesty throttle body.
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While I have a pretty good grasp on how the automatic transmission works, I fail to fully grasp some details.

First this link has a great guide that has been interpreted for we non German speaking folk.....

https://kourt.dehaas.com/westy/transaxle/010-repair-guide-translated.pdf

Recognize that these pages were a book with two pages side by side so images spread across the crease. Not so in the scanned version, you have weird little images on the side of the pages.

While I understand the valve body acts as the brains of the transmission deciding what gear should be engaged based upon shift lever settings and oil pressure feed back from various areas but largely the governor.

What is only lightly touched upon is how the down shift lever works.
It obviously does way more than just switching a down shift valve.

It influences shift points some how based upon its rotation controlled by the gas pedal.

Can anyone provide more detailed operational information?
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[MarkWard]

Regarding the VW 010 automatic. Prior to that, VW used a vacuum modulator to tell the automatic engine load. Many other manufacturers did the same thing. It worked well because intake vacuum is a good reference for engine load.

I can’t tell you how the 010 lever works. Basically it is using pedal position and the governor to determine engine load. It works, but is not a true indicator of engine load.

Based on your other thread data points, the internal valve is controlling upshifts because by modifying the geometry you’ve seen the shift points change.

I rebuilt some automatics and even went to VW school for the automatic 010. I might even have some pro training from the class. I don’t remember enough to answer your questions and what I took away from the training was to be neat and organized. There is a member who posts time to time Atlas Shrugged. He seems very knowledgeable about these units. It might be worth reaching out to him.
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[skills@eurocarsplus]

the kickdown valve is nothing more than a spool valve that allows oil flow at different positions

it's linked with the throttle pressure valve which does basically the same thing. it re-routes oil thru the valve body and controls the upshift or downshift depending on position.

you messing with the length of the throttle rod to try and make an aftermarket part work is your downfall

it's pretty clear that the throttle body you're using has introduced more problems than it's worth.

bottom line? the lever has to be "locked" all the way forward for kickdown and all the way rearward for idle

it HAS to move in a linear fashion for the trans to work correctly. I know...you're fucking with micro switch adjustments but it seems that it isn't going to play out they way you want.

either modify the T body so the switches do what you want or throw it away and get a OEM one rebuilt. Fooling with the trans is not your answer
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[danfromsyr]

the stock automatic throttle linkage is adjustable AT BOTH ENDS to allow you to set the throttle body to where it needs to be and then adjust the throttle cable/rod to allow the pedal to be at idle for idle and kickdown at full throttle.

in the stock WBX since kickdown is attained by the over-reach spring pportion, that ensures that the throttle body is ALWAYS at WOT when you kickdown allowing the ECM to ignore the O2 feedback for that time.


the kickdown/throttle lever on the AT is a 'manual valve' and it does impact the 'driveability' by setting shift points relative to throttle position.
so if you have that adjusted to far forward it'll shift more aggressively than if you have it adjusted to far rearwards it'll shift soft and slip the plates more.
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[kourt]

One interesting learning point about the Vanagon 090 transmission is that so many engine conversions fail to get the throttle linkage right.

I had a Bostig and the linkage was effective for only half of the throttle conditions. Most of the other conversions waffle it.

So if you want to learn by doing, study some conversions and drive them. Then go back to the original linkage and study it.

kourt

[djkeev]

[djkeev]

[djkeev]

I'm thinking of making a new kick down lever.

I will copy kick down shaft hole "A"
I will copy the location of the 8mm ball stud for the accelerator cable.

I will copy the bends for the upper portion.

For hole "B", where the accelerator rod mounts I will make an 8mm slot rather than a hole. This will allow me to easily adjust this point on the Van.
I believe being able to adjust this location is key to proper shifting.

I do not know where this hole must be (dimension X) but I do know that mine was at 5 1/2" and I moved it to 5 5/8" by flattening out the 45° bends.

I figure I'll make the slot 5 1/2" at the uppermost point and come down shorter.

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http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[Shonandb]

You can drill another hole in the kickdown lever for the cable attachment after adjusting the rod to the throttle body as this will give you more or less throw to match the WOT and idle range.
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76 Westy with a 2.5L Subaru SOHC + Vanagon (010) Automatic Transaxle
Build & Trip Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=758760
Previous 1973 Panel Bus:
Click to view image

[djkeev]

[kourt]

The governor is a major player, for better or for worse.

The governor is gear driven from the final drive pinion, and it regulates the ATF pressure by its rotational speed. This controls shifting in response to vehicle speed.

Conversely, your throttle linkage is how the transmission is controlled by driver throttle demand.

I thought it would be helpful to visualize an example of differing highway onramp approaches as an example, but the governor and throttle linkage are so carefully tied together, that it is hard to separate the two.

Add on top of this the nuanced design of the throttle linkage, with the use of springs, and you can see why I've complained about engine conversions getting it wrong. They all try to simplify the linkage, but end up robbing it of its coordinated elegance with the governor.

kourt

[djkeev]

OK....... more hours burned.........

Here is inside the 090 NH transmission case. (NH is the designation for a WBX transmission. NG is Air Cooled)
The pencil end is pointing to the gear selection lever......

This is the other end of the gear selection where it operates the parking pawl.

This inner single lever is connected to the kick down lever shaft...........

This lever will swing to the extremes that the case allows......there is no detent, no spring, no nothing......

Once you slip in the valve body, you can see how the lever works and its movement becomes much more confined.

By my thumb you will notice two things.......

1) a black flat spring with a roller on the end. This roller provides the kick down detent we speak of.

2) a flat spot on the bottom of the lever contacts the top of a sliding piston valve.

(The round 90° bent rod goes into the gear selector lever, but I didn't bother hooking it up for the photos)

On the valve body, you can see the piston that is in contact with the lever.
You can see how far it is extended out. (A smart man would have measured that distance! 🤷‍♂️ But...... I've never been accused of being smart)

EDIT:
18.5 mm fully extended.
It will push in to 1mm exposed

I can easily push the sliding valve in until it is flush, it is spring loaded.
There is also a threaded adjustment that can be made but everything I read says...... DO NOT ADJUST!!

The piston is held in by a steel plate and two Phillips screws...... you know I'm going to remove those screws don't you?

Well of course I am!

As the last screw came lose I was sure to hold the plate in place with my fingers and then gently let it lose. I didn't want springs or items propelled by springs shooting across the work area...... never to be seen again.

I then gently pulled out the piston it is officially called the "Kick Down Valve".
I placed a ruler next to it.......

I then fished out the spring and the next slide valve called the "Throttle Pressure Valve".

The whole assembly which is operated by the kick down lever.

For giggles I was able to get a photo of the bore for the kick down valve, you can see holes and slots for oil flow.....

I also got a shot of the throttle pressure valve bore, also milled for oil control.....

Here is a blow apart of the NH valve body.......

A close up of the kick down lever parts.......

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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[djkeev]

What is my take away from this exploration?

1) as the kick down shaft rotates the lever pushes against the Kick Down Valve slowly but surely pushing it into the bore in the throttle body.......

2) the detent just before kick down is also a very real spring .....

3) the kick down lever is moving valves which not only control kick down but it also operates a valve which I believe controls upshift points. The THROTTLE PRESSURE VALVE.

4) I do believe the Governor plays a major role in shifting but it is serving more as a back up system or a safety valve to the THROTTLE PRESSURE VALVE to prevent engine over reving.

5) there is an absolute direct relationship between the KICK DOWN LEVER position and THROTTLE PLATE position.
I also think the margin of error between the two working together is quite small.
I think that adjusting it precisely is going to be a major PITA!

6) the adjustment of the gas pedal is only to fully move the kick down lever.
It has no interaction with shifting or kick down...... unless it is incorrectly adjusted and it is not fully moving the kick down lever.
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Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[djkeev]

What are my next moves?

#1) reinstall the VW throttle body, I've worked the sticky out of it but I pan to purchase a rebushed unit.

#2) build a new kick down lever.
But I'll make this lever so I can adjust the height for the throttle rod.
Between adjusting the length of the throttle rod and the length of the kick down lever, I should be able to dial this in to a happy compromise of throttle, shift points and kick down.
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http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[skills@eurocarsplus]

Dave, I like you a lot and it's taking everything for me not to scream at my computer

like I said, it's a spool valve that controls oil flow which then controls the shift points.

You seem to be trying to monkey fuck an aftermarket throttle body to make the microswitch work.

all of the shit you're trying to do is introducing more issues where there were none before this throttle body.

Bottom line, and dead simple... the kickdown lever needs to open the throttle blade wide open.... or close to it at kickdown and close at idle

this is so easy to achieve it would be funny if it weren't so sad you're chasing your tail.

you need to modify your microswitch to work, period. all of this fucking around with linkage etc will NEVER get you the result you need or want

as an aside... if your throttle blade is off a few degrees it does ZERO for performance. you need to worry about making the GW microswitches work with the OE stuff...not the other way around.

I assume this is what you have?

https://gowesty.com/products/gowesty-throttle-valve-housing

by the looks of it, there is ZERO adjustment for the TPS and that's bullshit

it should have slotted 'ears' to make the adjustment

like this:

https://www.partsgeek.com/7xlr5tw-subaru-forester-...38EALw_wcB

This is the joy of making aftermarket shit work. I would have modified that throttle body before going down the road of screwing with the linkage.


Do you not have the ghost view of the valve body circuits? Not that it will help you because you really need to make the gas pedal and trans lever work the way they were designed but it may help you understand the oil flow and how it works.

here is a good video on how a spool valve works...which is basically what the valve body is full of:

https://youtu.be/Jfdmrm4A99s?si=jpIo-y1eeaoj5Ry_

I can get you the circuit if you'd like. Let me know
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[Shonandb]

I set up my kickdown as Skills instructed and it works perfectly.

I have a cable running from the top most section of the kick down lever (on my Vanagon 010 auto trans) that goes to the throttle mechanism on the engine. I adjusted the cable so that at WOT the kickdown lever is all the way forward as far as it can go. I know that at full throttle (WOT) on the engine, my kickdown lever is all the way forward and will downshift my transaxle to 2nd.

After making sure that the kickdown lever to throttle mechanism on the engine is adjusted correctly, I then experimented with the cable from the kickdown lever to the accelerator pedal in the cab.

At idle, my gas pedal is all the way up and I selected a point on the kickdown lever to drill an additional hole a little higher so that when the gas pedal is all the way to the floor, my kickdown lever is all the way forward and my throttle is wide open.

When driving, my shift points are well positioned and when I need to pass or accelerate, I press the gas pedal to the floor and the transmission downshifts to 2nd and off I go.

It works well but as I have a Subaru engine, I manually downshift to 2nd at times as I don't always need the full HP that WOT brings to accelerate, pass a vehicle, or get up to speed.

When you check your kickdown lever, when it is held as far forward as it can go, is your throttle butterfly wide open (are you at WOT) on your engine?

Additionally, when you press your gas pedal all the way to the floor, is your kickdown lever all the way forward and is your throttle valve/butterfly wide open?

If yes to both, then I think that you have an issue with your internal transaxle kickdown settings/adjustments or your kickdown lever is worn and has too much play causing the shift point issues.

On a similar note, when I first got my drive train installed and running, I used a single throttle cable from the gas pedal to the throttle at the engine and forgot to attached a pinch nut at the kickdown lever. When I drove it, the shift points were way off. After taking a look and connecting the kickdown lever, the shift points improved but were still too early so I did a search on The Samba threads and readjusted as above and the shift points improved and the kick down function worked.
_________________
*******************************
76 Westy with a 2.5L Subaru SOHC + Vanagon (010) Automatic Transaxle
Build & Trip Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=758760
Previous 1973 Panel Bus:
Click to view image

[skills@eurocarsplus]

^^^^

As far as I can tell he's trying to futz with this aftermarket throttle body to get the microswitch to work

You and I having subaru's did pretty much the same thing. That said...

stock or otherwise... adjust the throttle cable so you have the kick down lever locked into it's detent when the pedal is to the floor and at it's rest position when released

THEN adjust the throttle. It's a 2 step adjustment. In all of Dave's threads it seems he is chasing the operation of the microswitch on this aftermarket throttle body.

The problem seems to be (and he's unwilling to realize) that it's the throttle body causing the problems.

He's trying to overcome a shit design on the T-Body by fooling with the trans linkage.

This is like trying to lose weight while exercising on a bad diet...you can't out exercise a bad diet just like you can't out engineer a shit product.

Obviously, this is a non issue for the manual trans people but for us automatic guys you CAN'T fool the kick down lever...it just isn't going to happen because (as seen in the valve body) it's on a cam that get's more progressive as the pedal is pushed.

basically what Dave is trying to do is put a timing belt on 2 teeth off and trying to compensate by turning the distributer... it ain't gonna work
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[djkeev]

Skills,
Thanks for your reply and time.

I listen to you, I've contacted GoWesty explaining my frustration with making their throttle body work on the automatic.
In short I said that I'd like to return it because of the design inadequacies.
I'm not sure that they will admit a design flaw or not, I'm sure that 100's have been installed on automatics with no complaints. Those hundreds probably run so much better with the new throttle body that they have nothing to compare to previous operation ...... so its great to them!

Anyway......
So far I've heard only crickets...... but in my experience they aren't known for fast replies.

Their TPS is adjustable and I adjusted mine.
When mine arrived there was no TPS closing at idle.
They had paint on every screw and claimed it is factory adjusted...... but it wasn't.
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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[kamzcab86]

[djkeev]