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Solving the Modern Overdrive with a Floor Shift using Mopar Parts


timkingsbury

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I will start this Blog entry off with a cut and paste from an entry I recently posted on the forum.

 

The preamble:

 

I am not a fan of the non-mopar t5 transmission conversion. A great deal of those transmissions have gear splits that
were meant for low horsepower, low torque engines and they just do not match up well to a flathead mopar. The are also in my opinion, a great deal of work to make the conversion. There are many models of the T5 transmission, with several having very little overdrive to them. As some have pointed out, when I posted a chart showing a great deal of the T5 transmissions, in at least one case a member who is a huge t5 supporter, editted his post as his transmission was not what he thought it was.
That may should like a shot, it isn't meant to be, but what it is really is an illustration that a lot of guys have ventured into the t5 project without realizing what they are in for or what they even have. I do completely understand why so many having went though the conversion process, claim to be happy. They may indeed be, with all the work behind them and in some cases guys are not about to admit that they wished they have never went that route. At least one of those recently posted on the blog here, who was beyond frustrated with the project effort level and the results.

 

Now having said that, there are some t5 with better splits and more overdrive than others, but given the work effort, the cost and the end product it still wouldn't be my first choice.

 

The goal:

 

I wont go into the ramble on why I still prefer the Mopar Overdrive solution, and why for me the 1952-56 R10G Borg Warner overdrive gives you in essence a 6 speed transmission, and concentrate on the pursuit of many. That being a easier to
find Overdrive transmission that provides you with a decent level over overdrive, with a decent gear split and for many,
the desire to have a floor shift in their car.

 

There is also those with earlier (pre-1939) Mopar's that had a floor shift transmission and would like to keep that original cab look, but want an overdrive and cant find one of the floor shift overdrives from the 30's that came from Chrysler/Desoto.

 

The Solution:

 

A 1975 - 1987 Aluminum A833 4 Speed Transmission with overdrive.

 

Yes, the A833 "bullet proof" transmission is the in essence the same transmission as the "cast iron" version of the 60's that went behind the 426 Hemi. Those transmissions tend to be very pricy and 4th is direct drive 1:1 so since were looking for Overdrive, the older cast iron A833 doesn't fit the bill. Although the 1975- 1987 Aluminum A833 certainly does!

 

The details:

 

Lets start with for the earlier Plymouth we have to deal with the "X" frame so the A833 becomes a great candidate for this application.

 

I would use the Aluminum cased a833's 4 speed with overdrive which started part way into 1975 and went thru until mid 1987.

 

Here is the gear splits:

 

1st: 3.09:1, 2nd: 1.67:1 3rd: 1:1 4th: 0.73:1 (Trucks used a 0.71:1 fourth)

 

The overdrive configuration with a 23-spline input appeared in these vehicles:
o 1975 to 1979 Valiant, Duster, Dart, Scamp, Swinger, Volare, Aspen (3.09:1 ratio first gear)
o 1975 to 1987 Dodge light-duty pickups and Dodge and Plymouth Vans (3.09:1 ratio first gear)
o 1977 to 1979 Diplomat and LeBaron (3.09:1 ratio first gear)

 

The "Coles note" version of what you will need to do and I will mix in the details concerning the "X-Frame" which only becomes relevant in the models from the 1930's. You will be using the original bell housing, not the one that came from the vehicle
that had your donor A833 4 speed and yes ones like the bell housing in the pickups are large and might leave you
the impression your on the wrong track.
You will need and Adapter plate and screws to mount the transmission up to you stock bell housing. You do not
need to make modifications to your bell housing

 

* The Adapter plate kits (Plate and screws) are available from AoK. We do not have A833 transmissions for sale
You will need to change your clutch to fine spline and you will need to make an adjustment to the connection of the A833 transmission to the drive shaft. You can change the yoke on your drive shaft so it will connect up to the new transmission or in many cases this may be the opportunity to put in a modern rear end which will allow you to use a modern driveshaft with the A833 and the new rear end. Will talk about that more in a second.

 

** Note: Sept 2015 we sold the last Adapter plate and our Supplier cranks up the price to the point that we are looking for another
supplier. Will update this blog entry when we have more details.
Nov 2105 - as covered below, we have got a new supplier and have the adapters and bolts (as a kit) for $125 USD plus
shipping. That is the price for the next 25 at least and is priced really based on what the cost of the aluminum stock price is.

 

IMG 20151124 03076

 

 

You do not need to change your pilot bushing as it is the same as original.

 

On 1937 – 39 Plymouth cars (with the X-Frame), you can cut bottom of x frame loop off - (half off) to get the transmission in place. Some think it is fine to leave it with the piece of X-Frame taken out, although it is easily to get it back in place so that would be my preference. The the last one I saw done, they made a bracket to put the x frame loop and then fasten the half of the X-Frame back in.

 

Depending on which A833 transmission you get, you may have to make a minor modification of the bearing retainer. It is the round plate that has 4 bolts holding it on to the tranny.. A couple of the A833's have a longer housing and you need to unbolt it and cut some of the housing off. About an 1” 1/8”,

 

For the 1937 we recently had a hand in, he used a 1966 dodge cornet rt clutch (10 ½”) and pressure plate that he bought from napa (called a clutch pack), however there are lots of great and inexpensive options there.

 

You can change the yoke on the drive shaft to hook up to the A833 or change the rear end.

 

For the 1937 Plymouth project I just mentioned, he put in a 1963-64 Chrysler New York rear end and it fit in perfect. It also had 3” x11” brakes and positraction and a 3:55 rear end ratio which with the a833 gives you 2.59 results as well gave you the emergency brake on the rear axle since you loose the emergency brake drum when you swap out your original transmission.

 

Here is a handy chart on mopar rear ends that may come in handy depending on your application

 

rear ends

 

For the 1937 Plymouth which already had a floor shift, the shifter had to be modified slightly so it came up in the original position. Basically the shifter was modified to move it to the right (passenger side) and then up towards the firewall slightly ,to have it come up the original shifter position. Despite the two bends it shifts perfectly.

 

If you are putting the A833 in an early pickup the shifter had to be modified to go towards the passanger 3/4" and then towards the firewall 1 1/2 and it shifts perfectly. In the pickup if your interested, when the snow leaves (about july.. lol) I have to go have a better look at the rear end. I cant remember if the drive shaft was modified to put the modern yoke or if the rear end was changed. I do know the A833 came right out of my Dad's 1982 Dodge pickup.

 

The net in either gives you a floor shift transmission with decent overdrive ratio (0.73:1 or on the Trucks 0.71:1) and decent gear splits!

 

For cars from the 1940s and 50's you don't have to deal with the "x-frame" so the project is even simpler. In terms of the shifter position coming through the floor, you will have a slightly better starting point than other modern floor shift transmissions, and keep in mind you can modify the shift to bend it towards the passenger if you like or towards the firewall.

 

Personally in a 1948 Plymouth business coupe, we made no modification left (towards the passenger side) but bent it forward towards the firewall a bit just because for the driver (6 foot 2 inches) that is just where it felt the best. The point being you have a fair amount of flexibility in where you want the shifter to come up through the floor and then bend it to work best for you. For the 1946-48,Plymouth it seem the US cars may have a slightly different back mount with a cross over member being notched for the standard 3 speed. To then accommodate the lower a833 transmission, I am told you have to notch that cross over frame piece slightly to use the adapter and A833 transmission. For the 1948 Canadian Plymouth we did not have that issue.

 

* Jan 2016 - We have been able to pull stock transmission out of 1946-48, 1949, and 1950 Plymouths made in USA and every
one would require modification of the cross member as the A833 4 speed being deeper than the stock
transmission is going to hit the cross member..

 

Also remember that when you swap out your original transmission and move to any modern transmission, you have to consider what
your doing for an emergency brake. As I covered above, the change of the rear end to a more modern rear end may solve that problem for you. There other options,

 

1 such option would be something like - E-Stopp Electric Emergency Brake with Remote Push Button

 

http://www.estopp.com/

 

Here is the A833 illustration right from Dodge/Chrysler and then a view angles of a rebuilt tranny.

 

a833 mopar transmission 1975 80 illustration


a833 mopar transmission 1975 80 3


a833 mopar transmission 1975 80 2


a833 mopar transmission 1975 80 1


a833 mopar transmission 1975 80

 

** Dec 22 2015 - Just to be clear, the A833 adapter plate is for Mopar 833 Aluminum 4 speeds for use in Mopar cars, and was not designed for use with the - 1981 -1986 Chevy/GM Truck Overdrive which I believe is a 833/RPO MY6. We were contacted in May by a customer and in the conversation it became apparent he was considering using a GM version of the transmission and he was told there appears to be a great deal of difference between it and the Mopar version of the A833. It appears he has been able to make modifications and get it to work and we will attempt to get a report from him, but up until now we have had zero experience trying to use
A833 chevy truck transmissions with this adapter. That doesn't mean that this conversion cant be successful, but it does mean we don't have experience in doing this.

 

There also appears to be interest in an adapter plate for the lighter truck bell housings, which as of now our adapter plate would be viable only for the 1955 and newer 1/2 tons using the column shift 3 speed and utilize the car style bell housing. The floor shift heavier 3 speed and lighter for speed (top bell housing below) and the heavier 4 speed in the 1 ton and lighter 2wd trucks with heavier 4 speeds that utilize the offset bell housing (bottom bell housing below) will not work with our current adapter plate and an a833 mopar 4 speed.
Depending on demand we can make adapter plates for either. Let us know if you are interested.

 

Dodge Truck Bell housing (on top is pickup heavy 3 speed & light 4 speed transmissions & bottom is heavier 4 speed in 1 ton & lighter 2wd trucks)

 

Feb 5 2016 -

 

Well mission accomplished. We now have an adapter plate for the both heavy 3 speed floor shift and light 4 speed bell housings and heavier 4 speed bell housings. Bellow is the truck adapter which works for both, then a picture of it with the car and light 3 speed column shift for tucks, and then a picture of the two truck bell housings that the new adapter plate works with. Price is going to be $135 & shipping for the kit. The kit will be the adapter plate and 4 bolts required to mount the adapter plate to the truck bell housing.

 

AoK - Tranny Adapter plate for connecting an A833 overdrive to a Dodge/Fargo truck bell housing that had a heavy 3 speed, light or heavy 4 speed tranny


AoK - Tranny Adapter plates for connecting an A833 overdrive to a Dodge/Fargo truck bell housing that had a heavy 3 speed, light or heavy 4 speed tranny & Car/light truck 3 speed


Dodge Truck Bell housing (on top is pickup heavy 3 speed & light 4 speed transmissions & bottom is heavier 4 speed in 1 ton & lighter 2wd trucks)

 

 

Bottom line: In the continental United States car adapter plates are $140 shipped and truck adapter platers are $150 shipped. Outside of that area cars are $125 + shipping and trucks are $135 + shipping.

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I really like the layout of the A833 transmission, especially the overdrive until you have to work on the overdrive.  The reassembly of the backend before you install the tail housing can be quite challenging.  But hey, how often would you have to work on the transmission unless you are a gear-bender blacksmith that doesn't put the clutch in all the way.  So, I have a 1948 Plymouth Coupe and want to put in an A833 -- the question is:  HOW DO YOU GET an AoK Adapter?  I have tried to find anything on the AoK -- is it a company, a person -- WHAT???   Any help out there would be appreciated.

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Thanks Tommy -  and MakeMineMopar as I will email you...   Sorry I have buried the lead. 

 

You can get me  via email  -  fargopickupking@yahoo.com   which is me tim kingsbury or by calling George Asche  Jr  

814-354-2621 or you can also get me via my cell at 519-766-5695..    whatever works best for you !

 

Tim

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November 26th -  Update
 
Happy Thanksgiving....  and we have gotten a new source to make out adapter plates.
The issue was our past supplier wanted to more than triple the price of the adapters. We sought
out other suppliers, and the issue was the material, and specifically the grade of aluminum that we were
using.  We could have changed to a steel adapter plate, but it would of course be a lot heavier and
susceptible to rust, so we just were not willing to go down that path.
 
In the end, we sourced out the aluminum. and then using our pattern a new supplier.
 
The end result, is they are a little more expensive, but we think at $125 for the kit (plate and screws) it
is still very good value, and really is something that we are doing as more a public service to provide a
mopar alternative than anything.  
 
Here is the picture of the 1st pile that just arrived, and we will have a bunch more coming next week.
 

IMG 20151124 03074

IMG 20151124 03076

 

Bottom line is they are $125 USD plus shipping for the car adapter kit or inside the Continental United States it would be $140.

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** Dec 22 2015 -  Just to be clear, the A833 adapter plate is for Mopar 833 Aluminum 4 speeds for use in Mopar cars,  and was not designed for use with the  - 1981 -1986 Chevy/GM Truck Overdrive which I believe is a  833/RPO MY6.   We were contacted in May by a customer  and in the conversation it became apparent he was considering using a GM version of the transmission and he was told there appears to be a great deal of difference between it and the Mopar version of the A833.  It appears he has been able to make modifications and get it to work and we will attempt to get a report from him, but up until now we have had zero experience trying to use

A833 chevy truck transmissions with this adapter

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Update on A833 Transmission Adapters.

 

We now have a 2nd Adapter plate that will work for the 2wd truck bell housing with the floor shift heavy 3 speed, light 4 speed or heavier 4 speed transmission.  Bellow is the new Adapter. Then a picture of the car Adapter plate and Truck Adapter plate, and then a picture of the two truck bell housings.

 

 

 

AoK - Tranny Adapter plate for connecting an A833 overdrive to a Dodge/Fargo truck bell housing that had a heavy 3 speed, light or heavy 4 speed tranny

 

AoK - Tranny Adapter plates for connecting an A833 overdrive to a Dodge/Fargo truck bell housing that had a heavy 3 speed, light or heavy 4 speed tranny & Car/light truck 3 speed

 

Dodge Truck Bell housing (on top is pickup heavy 3 speed & light 4 speed transmissions & bottom is heavier 4 speed in 1 ton & lighter 2wd trucks)

 

 

Bottom line:  In the continental  United States truck adapter plates are $150 shipped which is $135 and $15 for shipping

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6 hours ago, 49 bisiness coupe said:

I have a 1950 Dodge coupe with a fluid drive transmission will the A833 adaptor work on the extra deep bell housing or do I need to use a Plymouth bellhousing? 

Howdy 49BC -  Actually it wont really be relevant in term of the adapter plate, although I expect it will fit on the bell housing. The issue is the a833 4speed does not have a long enough input shaft to work. On the overdrive front, we have done it many time to use the r10g1 overdrive from a 1952-56 Plymouth and then change the input shaft to a long input shaft and throw out bearing to work with the fluid drive situation.   Whether there are long shafts available for the a833 I do not know,   I do know guys have switched the Plymouth bellhousing to go with a standard transmission or overdrive but I honestly have no experience in terms of what is involved.  I can try and find out for you.  In the mean time, here is a picture of the r10g1 with the long shaft I was referring to.

1952-56 overdrive trany.jpg

Edited by timkingsbury
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4 hours ago, pflaming said:

OR:  I am getting ready to put a Volvo OD behind my stock 218 on my '53 Suburban with three on the tree, then this floor shift attachment. 

IMG_1048.JPG

Not quite sure what this has to do with either the fluid drive bell housing or the a833 conversion,  but hey ..  its interesting. So in your picture are you saying that is a 3 speed transmission with a Volvo overdrive ?    Or is the picture to illustrate making the standard tranny a floor shift ?  I have no issue with your post, just trying to determine what your trying to illustrate here ?

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Primarily the fabricated floor shift. I will add an overdrive later. I've found and sold 6 R10 OD's. My personal concern on them is the potential cost to rebuild one including all electrical. From my causal observation that is a bit technical and the solenoids are not Walmart items. Yet in good shape they are historically quite dependable. 

The shifter I fabbed from a photo, not my design. It is uncomplicated and will serve my purposes very well. The tranny and OD are not on the engine yet. 

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On ‎24‎/‎08‎/‎2017 at 1:35 AM, pflaming said:

Primarily the fabricated floor shift. I will add an overdrive later. I've found and sold 6 R10 OD's. My personal concern on them is the potential cost to rebuild one including all electrical. From my causal observation that is a bit technical and the solenoids are not Walmart items. Yet in good shape they are historically quite dependable. 

The shifter I fabbed from a photo, not my design. It is uncomplicated and will serve my purposes very well. The tranny and OD are not on the engine yet. 

Lol, ok so it really doesn't have much to do with this thread. I likely should start a new topic on just floor shifts.  In terms of the r10g1 I can price out all of that for you. Its likely not as bad as you think. Of course that will be column shift.  My buddy George Asche has literally done hundreds of them. If they are decent rebuildable  they cost $450 to rebuild + parts.  What is included is new bearings, bushings and gaskets. I would guess its 80% + that George does for that. If gears are  ground, or people want fast seconds or there are parts missing well that starts to add up. The wiring, George hand makes wiring harnesses for them, as he does for the earlier r7 or r6 of which there were the 1940 and earlier that are floor shft. But from kickdown switches, overdrive relays and options switches to put on a steering wheel or dash are all readily available NOS or brand new.

In terms of the shifter in your picture, I think its going to be really close to the seat. But maybe your planning on buckets and want it way back.  In terms of adding an overdrive behind your existing transmission, Ive seen over the years many try it and a few got it to work but they were always a lot of work , extra connection points, bracing or brackets and there maybe some out there but I never saw one that then had 20-30-50,000 miles + on them.

But back to floor shift, there are always people looking to change a column shift setup to floor shift so I will start a thread and if you and others want a place to start documenting and discussing ideas, go for it!

 

Tim

 

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Tim, that response is a fantastic example of professionalism. You could have bashed me 10 ways to Rome, instead, you convinced me that if I'm serious about an overdrive, I should stay with what was designed for my transmission. Yes, it does sit back but I'm putting in bucket seats and the  shift lever will be in the area of my knee. 

Marketing this is not my current goal, that goal is a shifter for my car for me. I have sold three OD's to George so we've met on the phone.

Thank you for your response, once I have driven with it Ivwill report back. With an upcoming knee surgery Sept 5, my next project is War and Peace, Leo Tolstoy. The book is by my elbo as I type. 

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11 hours ago, pflaming said:

Tim, that response is a fantastic example of professionalism. You could have bashed me 10 ways to Rome, instead, you convinced me that if I'm serious about an overdrive, I should stay with what was designed for my transmission. Yes, it does sit back but I'm putting in bucket seats and the  shift lever will be in the area of my knee. 

Marketing this is not my current goal, that goal is a shifter for my car for me. I have sold three OD's to George so we've met on the phone.

Thank you for your response, once I have driven with it Ivwill report back. With an upcoming knee surgery Sept 5, my next project is War and Peace, Leo Tolstoy. The book is by my elbo as I type. 

 

4 hours ago, pflaming said:

I did not realize your post was a blog until a moment ago, which calls me to double down on my apology.  

Paul

 

Hey Paul -  Its not the Kingsbury or Asche style to go bashing people and because it is our blog, I would prefer to exercise some tolerance and flexibility when in my mind its clear someone just wandered down the wrong road.  As well the idea of floor shift concepts isn't a bad idea for a topic so I will start one.  But no apologies required.  Now lol, if it was a chevy part, or t5 suggestion, well I would likely be suggesting your in the wrong church!.  Have a great one and good luck on the knee surgery.

Tim & George 

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12 hours ago, pflaming said:

Tim, that response is a fantastic example of professionalism. You could have bashed me 10 ways to Rome, instead, you convinced me that if I'm serious about an overdrive, I should stay with what was designed for my transmission. Yes, it does sit back but I'm putting in bucket seats and the  shift lever will be in the area of my knee. 

Marketing this is not my current goal, that goal is a shifter for my car for me. I have sold three OD's to George so we've met on the phone.

Thank you for your response, once I have driven with it Ivwill report back. With an upcoming knee surgery Sept 5, my next project is War and Peace, Leo Tolstoy. The book is by my elbo as I type. 

From one Paul to another Paul, I have known George and Tim for around 20 years now and did have the opportunity to meet Eddy Kingsbury at Chrysler Carlisle in 2009. Classy, professional and all of them were off the chart smart and some of the modest guys I have ever met.   Like you I 1st met George and Tim via the telephone. That was great, but nothing like meeting them in person. If you ever have the opportunity, I would strongly suggest it should be on the top of every true Flathead Mopar enthusiast bucket list.  Just don't wait to long as George is getting up there and Tim's Dad who I intended to go north to Canada to see the following spring, passed away that fall. That is not to take away from Tim although there is nothing like talking to guys who were there in the early days, or at least the 1940's , 50s and 60s and in the forefront of Performance Flatheads back then.

My apologies for the speech but I just thought  it was appropriate when two good guys who maybe don't seem to know each other quite as well, might just have ran into each other in the back wood, both thinking the other had their guns drawn!

Paul M

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