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4 speed Saginaw

5K views 12 replies 5 participants last post by  FireGuy153 
#1 ·
Hey guys. Bought a 4 speed Saginaw trying to figure out what shifter and rails I need to make it work in my 64 no console and bench seat.
 
#2 ·
I think flea-Bay will be your best bet. Hurst used to make an Indy universal shifter for the Saginw and a Saginaw in a first gen Camaro with a 307-327 SBC. They no longer sell them new.

Problem with a Saginaw is they are torque limited and were designed to go with a six cylinder Corvair initially. Because there were not a lot of cars with a Saginaw in them from the factory there were few shifters available.

Big Dave
 
#5 ·
Not all Saginaw Trans are the same. A friend of mine rebuilds them and has taught me that the 2 rings (3.11 First) are stronger. I also believe the 1 ring is too. I just bought a 2 ring for my truck. I won't be racing with it though, lol.
 
#6 ·
When I bought my current '63 Impala convertible (bench seat), it had a 4 speed Saginaw (origin unknown, but certainly not a full size '63). It had a Hurst competition plus shifter body and appropriate linkage rods. I do not know any specifics on the linkage.

When I swapped to an AutoGear M22W 'Muncie' transmission I also used the Hurst Competition Plus with the 'installation kit' for the Muncie.

What I did discover was the shifter bodies for the two transmissions were identical.

Highly recommend the Hurst Competition Plus over the OEM GM shifter. That was in 2014, I do not know what Hurst sells now.

I've attached a pic of what mine looks like. The shifter plate is from a '61 SS (available from Show Cars, a similar '62 version too) and the handle is a bolt on (a la the Hurst) after market. What you can't see is the Competition Plus under.

If you need parts, I've had exceptional service from these folks:

https://www.4speedconversions.com

I replaced EVERYTHING but the pedals (fork, z bar, push rods, springs, EVERYTHING) and their parts fit like a glove.

Pete
 

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#7 ·
The heavier the vehicle the more the torque rating will limit you. I had a three speed in my '61 Apache 3500 that would break if I put it in reverse off road (that is to say a level grassy drive way). Worked fine a '55 Chevy car but the one ton truck with a utility bed and crane was too much mass to move when used even with a 235 six cylinder.

The Borg-Warner T-5 five speed was designed to go into Ford's four cylinder Pinto and Mustang II. Put it behind even a 305 SBC in a third gen Camaro and it breaks the first time you get on it. Same with the Corvair four speed designed in 1959 for a 90 horse six cylinder engine. The same gear set that used in the Corvair aluminum trans-axle case when placed in a cast iron case for rear wheel drive cars by Saginaw didn't get any stronger due to the small diameter of the shafts, small bearings, and the narrow face on the gears. Same issue with the four speed used in the Vega. It came out of an 83 horse 1.1 liter Opel SOHC four cylinder from Germany. You could bot it up to a 454 as the parts interchange but it wouldn't move the car at all before it broke. The 2.3 liter Vega four cylinder often broke that trans under use in the Cosworth variant.

With GM building larger displacement engines in the sixties to meet the public's need for speed even the Muncie was hard pressed to stay alive behind a 454 Chevy or a 455 Poncho or 455 Olds. That is why it was dropped in 1973 and replaced with the Super T-10 from Borg-Warner.

The torque rating of a trans is hard to find but the numbers exist on the internet. I wrote a post with the torque ratings of every trans that at the time was bolted up to a Chevy but I can not find it now.

Big Dave
 
#8 ·
Thanks I will check out the sites. Mine is a 0 ring. So it's a 2.89 first gear. The torque rating is 300 from what I read. This is only a family cruiser. So this is the cheaper alternative for me to go high way cruising vs a 700r4 or a pricey inflated muncie. All done I'm into it for 1200. Vs 2500 to 3500.
 
#9 ·
On the 63-64 Impala a large square is cut out of the floor hump and then a special sheet metal cover is bolted to it that has the hole in the correct place. As long as you get a shifter that is close you should be able to modify the screw down cover to move the opening to where you need it and it will look right as the opening the cover screws down to is pretty big. The main thing you have to look for is if you are a bench sear car you have to make sure the seat in the all the way forward location does not interfere with shifting or your not banging your knuckles on the dash or ash tray when you shift.
 
#12 ·
The 1963 GM OEM bench seat 4 speed had a tunnel extension, a seal, a rubber boot and a ring w/screws to attach the boot to the tunnel extension. I've attached a pic. No console. The console was SS only; which also got you bucket seats.

Here is the 'tunnel extension' (perhaps being referred to as a 'plate'), that is required:

https://show-cars.com/product/4345


The 'shift plate' that I used on my '63 bench seat Impala is from a '61 SS w/bench seats. I attached what it looks like on a '61.

Here's another pic of a '62 w/shift plate. If the shift plate and its mounting bracket were removed, you would have only the black tunnel extension where the boot and its mounting ring attached.

I never found an 'after market' boot/ring I liked. They all looked really cheap. I copied the 61 SS look and used the appropriate parts. My transmission is a new AutoGear M22W 'Muncie' with a Hurts Competition Plus shifter and linkage.

You may have difficulty finding the shifter linkage for the Saginaw. Some one found a way to make the Saginaw work on my '63 (as I bought it) but I paid no attention to it because I had no intention of retaining the Saginaw.

All this is simply info for whatever use you choose.

Pete
 

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#11 ·
Hole in the floor was cut on the assembly line with an acetylene torch (ragged edge with lots of slag). They then spot welded the shifter hump in place using a factory spec measured from the foot well to fire wall seam (detailed in the Fisher Body service manual as well as the Assembly manual). If no console was installed it had a molded carpet covering the hump with a rubber boot bolted to the hump.

If the hole was sawn out with a hack saw, a Saws-All, or a cut off wheel it was put there by a previous owner.

As far as the Hurst shifter goes all Competition Plus shifters shared the same body. You bought your car's kit based upon the type of seats you have (bench or bucket) and console or not, which determined which shifter handle you got; and the tranny had it's own mounting plate to bolt the shifter body to the tranny and individual rods to match the trans tunnel and transmission.

Big Dave
 
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