Technical How to convert a manual to automatic’63 Impala

How did you measure the driveshaft? What size clutch and brand did you use?

 

Do they sell the front drive shaft for 4 speed pre measured?

 

You would be best to have yours shortened by a reputable shop.

 

As I recall I left the original clutch in it because it worked fine, just swapped in the Muncie.
For my Nova I bought a complete clutch plate, disc and throwout bearing set from Borg Warner called a Power Brute, it even came with a splined plastic disc allignment tool, this was many years ago, not sure if they offer it anymore.

 

As a member of the "my left knee hurts like hell for hours after driving a stick shift" there are damned good reasons for swapping from a stick to an automatic in a 64 Chevy that could be bought from the factory with an automatic. We all don't have to do clutch dropping burnouts and many of us are not the least bit worried about loosing our manhood card if we drive an automatic as some seem to be.

I've got one of my trucks up for sale because the clutch takes so frigging much pressure to push that I hurt for hours after driving it. The truck sits too much of the time simply because I hate driving it but would get driven a lot more if it had an automatic. My 48 will get a 5 speed but will get a pressure plate that requires a lot less foot pressure to work. I'm not a stick shift hater but at 78 years old when I drive 20 miles to some place I want to go to it is a pain in the ass to get out of the truck and not be able to walk across the parking lot because my frigging knee hurts so bad from working the clutch that I can't walk.

 

I'm just curious why you want an automatic? We know you didn't ask "what can i do to solve this part of driving I dont like" but it can help if people know why you dont like it.

Is it the difficulty getting it into first gear with the non-synchro 3 speed? A synchronized 3 speed cures that,
Is it a knee pain vs. clutch pedal effort situation? A modern softer clutch can help with that
Is it a 3speed on the column is awkward and un-cool situation? A simple floor shifter can fix that.
Is it a gear ratio, car just revs too high on my cruising situation? a 5 speed swap can add performance and economy
Is it an "i dont want to shift, I want to keep my arm around my sweetie" situation? Good on you! Nothing wrong with cruising with your best gal....

I know it seems like a lot of guys are telling you what to do with your own car....and some times it is true that some think they know more than you, but to be honest most guys dont want to see you make a quick decision that isn't necessary because you may not have all the info. Please dont take all the 4 speed opinions the wrong way.

-rick

 

I found this [below] on the net for you, so you will need to shorten a 3 speed driveshaft 5-1/8" [or find a 3 speed overdrive "SM-319" front driveshaft]
A driveshaft is easy for a shop to shorten


Lengths of FRONT driveshafts

59-64 4-speed & 3-speed w/OD front driveshaft= 24 5/8"
59-64 3-speed & 59-61 Turboglide front driveshaft= 29 3/4"
59-64 Powerglide front driveshaft= 26 13/16"

Measurement is tip to tip length with front shaft completely disassembled.... front U-joint and slip yoke removed, center U-joint flange and center bearing removed.

 

Hey do you remember how much shorter the driveshaft needed to be?

 

Hey I decided to go with a Muncie M20 4 speed. So cut the front to 24 5/8?

 

Yes.

 

The transformation will put a big smile on your face on the first test drive, also, the M-20 transmission is the perfect four speed for heavier cars with low (numerically) rear gear ratios, it will be much easier to get the car rolling from a start, you won't be slipping the clutch and wearing it out prematurely.

 

Yeah you guys talked me into it. I kinda liked the 3 on the tree but the non synchronized 1st gear sucked. Did try double clutching but never worked. So far I’ve removed the old trans and linkage. I put a new clutch assembly. New slip yoke is being shipped. Waiting for that and just wanted to confirm the driveshaft cut length before it goes to driveshaft pros.

 

Yeah not supposed to downshift to first on non syncro three speed anyway. Supposed to come to a dead stop before downshifting to first. Had a bunch of guys stress that to me when I was going to run the exact same transmission (even from 1963 lol) in my 53 bel air till I found out it needed a bunch of work despite being supposedly "rebuilt"