model a 1930-aa-4 speed transmission

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RichardG
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model a 1930-aa-4 speed transmission

Post by RichardG » Mon Jan 18, 2021 8:39 pm

whats the best fix on the shift lever that allows the tranny to stick between two gears. i'm told the ball is worn,--weld and re shape ? i have not taken it apart yet, just trying to get some idea. thanks-- greg


Bill Dizer
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Re: model a 1930-aa-4 speed transmission

Post by Bill Dizer » Tue Jan 19, 2021 8:02 pm

I am not familiar with model aa transmissions but when I have seen it happen on slightly newer transmissions, they had a pin sticking out the inside of the top of the shifter tower where the ball fits, and a slot in the shifter ball that slides over the pin. Both the pin and the slot wear, which allows the the shifter to pivot a bit, and engage two shift forks at the same time, locking it up. With two forks moved, the shifter sometimes could be moved sideways and disengaged entirely from the forks.

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Pep C Strebeck
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Re: model a 1930-aa-4 speed transmission

Post by Pep C Strebeck » Wed Jan 20, 2021 10:02 am

Richard G wrote:
Mon Jan 18, 2021 8:39 pm
whats the best fix on the shift lever that allows the tranny to stick between two gears. i'm told the ball is worn,--weld and re shape ?
Definitely looking in the right direction. It is not just the ball on the end of the gear shift lever, it is also the slot on the shifting forks that the ball fits into as well. Welding up and re-shaping the ball and forks was/is one way to go. I had that same problem on Model A's in the past. I had to do that many years ago before replacement parts were available. For the standard Model A 3-speed, new gear shift levers and shifting forks are available, but I do not think they are available for the AA transmission. Here is a link from one of the Model A Chapters on rebuilding the Shift Tower:

http://www.santaanitaas.org/wp-content/ ... ration.pdf


The AA transmission is not "too much" different from the standard 3-speed. Please be careful when removing the spring on the gear shift lever, that retainer and spring become missiles very quickly and are normally aimed directly at your face.
"Remember son, there are two ways to do this: The right way, and your way” Thanks Dad, I love you too.

LOOKING FOR A LUFKIN No. 9A Height Gage Attachment.

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Pep C Strebeck
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Re: model a 1930-aa-4 speed transmission

Post by Pep C Strebeck » Wed Jan 20, 2021 5:06 pm

I found some photos of the tool I built to disassemble and reassemble the shift tower on the Model A. Like I had said in my earlier post, that spring is dangerous and it seems like it as a guidance system built into it that is aimed right at your face and eyes. Getting it disassembled safely is quite an exercise, but it getting it reassembled with a freshly re-plated gear shift lever and a nicely painted shift tower, without scratching anything is more than a challenge.

Complete tool, with disassembled tower..JPG

It is a pretty nice tool that gives you a stable working platform, holds the tower securely and more importantly keeps that spring held in place. With the lever handle it takes very little pressure to compress the spring and keep it compressed so you can take off the keeper.

Compressing the spring..JPG
Removing spring retainer..JPG

It also makes it easy to punch out the pins that hold the shifting forks in place and for removing and replacing the detent plungers for the shift rails.

Removing the plug for the detent plungers..JPG
Removing the shifting fork pins._2_2.JPG
"Remember son, there are two ways to do this: The right way, and your way” Thanks Dad, I love you too.

LOOKING FOR A LUFKIN No. 9A Height Gage Attachment.

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RichardG
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Re: model a 1930-aa-4 speed transmission

Post by RichardG » Thu Jan 21, 2021 10:21 pm

WOW--- GUESS ITS GOING TO BE MORE OF A PROJECT THAN I THOUGHT, THANK YOU AGAIN FOR THE SUPER HELP ON WHAT TO EXPECT IN THE TAKE DOWN, I HAVE A FAIR AMOUNT OF THINGS TO WORK WITH IN MY SHOP, AND THOSE PICTURES [PEP]- WILL BE VERY HELPFUL IN THIS PROJECT... A-S AND T-S- NEVER HAD MUCH TO DO WITH THEM- STUTZ-MARMON-PACKARD-RR- REO--ECT- WAS MY BREAD OVER THE YEARS- STUTZ BEING MY FAVORITE, THIS OLD FORD IS A AFTER THOUGHT, SEEMS NO ONE CLOSE BY DOES THIS STUFF ANY MORE, SO IM IT,WITH YOUR GOOD ADVICE WE WILL CONKER, THINKING WAAAAAY BACK IN MY YOUTH I DID HAVE 31 SED A CUT DOWN TO A MIGHTY NICE PICK UP, IM NOT A SMALL FELLA NEVER WAS, SO TO GET MORE ROOM WHEN OUT CATING AROUND I FOUND BY LIFTING UP ON THAT LEVER IT COULD BE SWUNG OUT OF THE WAY,,, NOW AS -U- KNOW THERE IS NOT MUCH ROOM IN A CUT DOWN MODEL-A- AND THAT HELPED A-LOT-- IVE HEARD THAT IN THE SEDAN THE REAR FLOOR BOARDS COULD BE FLUNG OUT AND GIVE STANDING ROOM--THOSE WERE THE DAYS MY FRIEND---

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Pep C Strebeck
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Re: model a 1930-aa-4 speed transmission

Post by Pep C Strebeck » Fri Jan 22, 2021 1:41 pm

Richard G wrote:
Thu Jan 21, 2021 10:21 pm
WOW--- GUESS ITS GOING TO BE MORE OF A PROJECT THAN I THOUGHT,
It looks and sounds more complicated than it actually is. Aside from a tool for the spring removal-re-installation, all standard mechanics tools. I know the Model A vendors sell a tool for the spring (made from a piece of pipe, I believe) and it works well enough for removing and re-installing the spring, but still does not hold the entire tower in place. There was a tool made by ACR that I had bought 20 years ago or more and that was one of the driving forces behind making the tool you see, it did not work well. I can not stress enough, BE CAREFUL WITH THAT SPRING!

The hardest part about doing this job is that there is no good way to hold the shift tower in place while you work on it, which leads to 99% of your accidents/problems. My first time doing this repair (1958 or 1959), the retainer almost got my eye and I always hated having to do it again after that. The 28-29 gear shift levers always held up much better than the 30-31 did, the ball on the end of the earlier gear shift never really wore that much. But something changed when the started making the 30-31 gearshifts, and the ball wore out a lot faster.

Again, the worn ball and forks will make it get stuck in between 2 gears, if your problem is it "popping" out of gear look at the shift rails, detent plungers and the spring for the plungers. Those little plungers are what are keeping the transmission in gear, a little bit a wear in each part adds up. I only worked on a couple of AA trucks and they were always much more tired (worn) than your standard Model A.



Just some more photos:
Holder for gear shift lever..JPG
Installing the spring compressor, #3..JPG
Spring compressor foot, bottom..JPG
spring compressor foot, top..JPG
"Remember son, there are two ways to do this: The right way, and your way” Thanks Dad, I love you too.

LOOKING FOR A LUFKIN No. 9A Height Gage Attachment.

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Mark Gregush
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Re: model a 1930-aa-4 speed transmission

Post by Mark Gregush » Tue Jan 26, 2021 11:36 am

Just clamp the tower in a vice, no need for all that fancy holder. (Nice job building it) Make sure the vent hole in the casting is open. It is about half way up on the back side. If you don't you will be blowing lube out the transmission.
I know the voices aren't real but damn they have some good ideas! :shock:

1925 Cut down pickup
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