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B&M Shifter for Automatic Trans Questions

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Gerald View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Gerald Quote  Post ReplyReply Direct Link To This Post Topic: B&M Shifter for Automatic Trans Questions
    Posted: Oct/17/2021 at 10:35pm
I recently found a nice 1969 AMC Javelin with the desired 390 engine and automatic trans with B&M shifter. Car will mainly be used as daily driver with hopefully beginner fun hpde. Seems l like most of these cars come with automatics. Would getting one like the one I am looking at with the B&M floor automatic shifter would be ok for hpde track events? What exactly is the difference between B&M auto shifter than stock? Can it be left in drive and or manually shifted? 1969 AMC Javelin, three or four speed automatic? Back in the time period of this car were there any "racers", racing / tracking auto cars? Ger. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2021 at 8:50am
B&M shifter ?  Sure you can put it in drive.No shift kits are available either.  No high stall converters either.  
Best to leave it alone.   If you want high performance TF is the way to go and thats another can of worms as AMC changed the crankshaft flange in 1972


Edited by purple72Gremlin - Oct/18/2021 at 8:55am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DragRacingSpirit Quote  Post ReplyReply Direct Link To This Post Posted: Oct/24/2021 at 8:58pm
If the shifter in your car is factory and works correctly I would leave it alone. I still use the stock shifter in my 70 AMX hooked up to a turbo 400 and I can't see any reason to change it. It is a street warrior and the shifter is fine with me !

FYI if the transmission in your car is stock it should be a borg warner M12 i think. Unless you are planning to turn it into a hot street car I would enjoy it and leave it alone.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Nov/19/2021 at 9:54am
To answer your question, yes, the B&M should be able to operate like a normal shifter. Many of the B&M shifters have a ratcheting function which is actually better for any racing
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'73 Javelin AMX 401 V8
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WesternRed Quote  Post ReplyReply Direct Link To This Post Posted: Nov/19/2021 at 4:21pm
You will need a little more information on what transmission is in the car and what shifter it is running.

Factory in your car was the Borg Warner M12 transmission, but it could have easily been swapped out of a Torqueflite or Turbo Hydromatic in it's life. The Borg Warner transmission is probably not going to be durable enough for any sort of serious track use, either drags or circuit but will be ok for the odd bit of fun here and there provided you don't abuse it too much. There are no performance off the shelf parts for this transmission. If you swap it out for a TF727 (or 904/998) or TH400 or newer GM 4 speed, all common swaps, then there will be a lot of transmission performance upgrades available to you.

With the shifters, there are basically two types, gated and ratchet, a gated shifter is basically the same as factory, the stick moves through an arc to select gears, typically P R N D 2 1 and there is some sort of gate, usually a button or lever that needs to be operated to shift between some gears for safety reasons, i.e. to take it out of park or to go front forward to reverse gear. With a ratchet shifter, the lever stays stationary and you click it forward or backwards to swap gears, it will also have a safety lockout to prevent going from forward to reverse.

The shifter itself doesn't change how the transmission works, so on a stock transmission, whether factory or aftermarket shifter, putting it into drive will still have it shift automatically though the gears and you can manually select the lower gears where required, but the transmission will override your selection if it is outside of it's factory established operating parameters, i.e. it wont shift into low gear if you are going too fast and it will stiff upshift automatically even if low gear is selected (in most transmissions).

So then you get into valve bodies, that is where the magic happens as it is basically the brain of the transmission, it takes various inputs and changes gears as required. In older transmissions this is done using various complicated mechanical and hydraulic systems while in newer cars it is all done with computers.

So from there, you would modify and or replace the valve body with an aftermarket one to get the transmission to operate how you want it.

Simple mods are things like shift kits, which will typically increase shift firmness and raise RPM of the shift points, from there you would get into an aftermarket full manual valve body, which only shifts gears when you want it to so you don't get undesirable things like the transmission automatically upshifting or downshifting in the middle of a corner. Manual valve bodies can be standard P R N 3 2 1 or reverse pattern P R N 1 2 3, the latter of which is generally preferred for racing because you cant accidentally shift from third into neutral at high speed and it is a slightly more logical sequence. Note that there is no longer a D (drive) option with a manual valve body because the transmission cannot shift automatically. The final iteration of aftermarket valve bodies would be the transbrake, which improves launch in drag racing applications.

Automatic transmissions are commonly used in circuit type racing, both now and back in the day, so there is no issue there.

I ran a factory shifter in my car for years and even modified the gates to work properly with a reverse manual valve body, but have now bitten the bullet and upgraded to a B&M Pro Ratchet, which was great for two runs until it melted the shifter cable (cant do that with a factory shifter). 


Edited by WesternRed - Nov/19/2021 at 4:25pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WhatISit Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2021 at 6:20am
Originally posted by WesternRed WesternRed wrote:

The shifter itself doesn't change how the transmission works, so on a stock transmission, whether factory or aftermarket shifter, putting it into drive will still have it shift automatically though the gears and you can manually select the lower gears where required, but the transmission will override your selection if it is outside of it's factory established operating parameters, i.e. it wont shift into low gear if you are going too fast and it will stiff upshift automatically even if low gear is selected (in most transmissions).


I didn't think that 727 transmissions can override the gear selection when chosen manually...
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'73 Javelin AMX 401 V8
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 304-dude Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2021 at 7:14am
Originally posted by WhatISit WhatISit wrote:

Originally posted by WesternRed WesternRed wrote:

The shifter itself doesn't change how the transmission works, so on a stock transmission, whether factory or aftermarket shifter, putting it into drive will still have it shift automatically though the gears and you can manually select the lower gears where required, but the transmission will override your selection if it is outside of it's factory established operating parameters, i.e. it wont shift into low gear if you are going too fast and it will stiff upshift automatically even if low gear is selected (in most transmissions).



I didn't think that 727 transmissions can override the gear selection when chosen manually...


Most likely your confusing late Th400 for TQ727 and other TQ models.

My 73 would down shift manually as long as I did not down shift beyond governor RPM limit. My late Jeep Th400 required a shift kit to down shift any gear. Something about the 2/3 valve having more wider cut for passing pressure.
71 Javelin SST body
390 69 crank, 70 block & heads
NASCAR SB2 rods & pistons
78 Jeep TH400 w/ 2.76 Low
50/50 Ford-AMC Suspension
79 F150 rear & 8.8 axles
Ford Racing 3.25 gears & 9" /w Detroit locker
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mramc Quote  Post ReplyReply Direct Link To This Post Posted: Nov/30/2021 at 1:15pm
Ok, To answer the question asked what is the difference between the stock AMC automatic shifter and a B&W shifter. The AMC shifter uses a hard rod with some adjustment to it. The B&W shifter is a cable shifter. I had this set up up in my 1969 AMX . But the reason was it was a 30 over 390 (396)Cubic inches give or take a little with a conversion kit for an AMC type Chrysler 727 Automatic.
If your swapping the transmission then this is the way to go. If you keeping the the stock transmission and NOT hopping up the engine too much it is Ok. But add a transmission cooler and an in line transmission oil filter , as the Borg Warners do not have a transmission filter per say, they a screen but not a filter. B&W also has switches you can add for back up lights and such. Just depend if sticking close to or stock or going modified. If you going for horsepower with an AMC engine then the 1972 Factory performance guide "Performance American Style " recommends that the Borg-Warner automatic transmission be replaced by a AMC version 727 . LRDaum
PS I used the B&W Quick silver shifter and I still think the gen 2 Camaro B&W console shifter kit will fit in the AMC console or close to it possibly with modifications. LRD
LRDaum
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