Converting automatic to 4-speed

[Mwmwall]

I'm looking at a 1964 Corvair with a trim tag that says it should be an automatic but it is now a 4-speed. How hard is it to do that correctly? Telltale signs of it being converted and converted properly and safely?

Body tag reads: ACC WD2MP3C5W. My understanding is that the second group, 2MP says it is an automatic (M) vs a stick (L). Could this be a factory mistake? Everything else seems to match, year, body type (Monza convertible), ext. color, int. color, other options.

Would the conversion, if done correctly, have any negative effect on value? I personally want the car I buy to be a stick.

Thanks

[bbodie52]

You are correct that ACC group 2M on the body tag would indicate the car was originally optioned as an automatic. Although a fairly involved process, converting to a manual transmission would be basically a bolt-on process of transferring the clutch and shift linkage components, transaxle, and clutch assembly and engine clutch housing from a donor car.

If the instrument panel was not swapped, the small shift display window may still be present where the automatic transmission shift lever was originally mounted.



The 1964 differential was unique in that it had mounting points to secure the transverse leaf spring that was unique to the rear suspension on the 1964 model year. If the transaxle was swapped for a manual transmission unit, the donor car would have to be a 1964. The rest of the shift linkage and clutch linkage could have come from an earlier Corvair.

1964 Corvair Camber Compensator

The engine serial number suffix code is a one or two-letter code that usually indicates if the engine was originally configured for a manual or automatic transmission. For example, here are some engine suffix codes for 1964...

110 hp Manual Transmission... "YN"
110 hp Automatic Transmission... "ZF"
110 hp Manual Transmission w/Air Conditioning... "YM"
110 hp Automatic Transmission w/Air conditioning... "ZG"
95 hp Manual Transmission... "YC"
95 hp Automatic Transmission... "Z"
95 hp Manual Transmission w/Air Conditioning... "YL"
95 hp Automatic Transmission w/Air conditioning... "ZD"

So if the 1964 Corvair you are looking at originally had an automatic transmission, and if the engine is still the original that came with the car, the engine serial number should indicate the suffix code appropriate for an automatic transmission vehicle — even if the transaxle is now a manual transmission unit.

[terribleted]

The main rear crossmember (not the transmission one but the big one that mounts the suspension) on most non 4 speed early models will not all allow fitment of a 4 speed transmission as the trans is longer. In cars from the factory that had 4 speed transmissions this unit was trimmed away for clearance and re-welded. Everything else would be parts swapping and bolt in. I would inspect the main crossmember above the front of the trans and make sure it is not just hacked out for clearance and not re-welded. Other than that if everything seems to be there and functions you should be ok.

I have a 63 Convertible here that was sex changed from automatic to a 4 speed. The crossmember is hacked and not welded. It also has an incorrect from transmission mounting crossmember that forces the powertrain too far back in the car. I don't how you are supposed to change a belt as the oil filter mount if touching the rear body crossmember providing no clearance to slip a new belt through. With the big stack of shims between the trans mount crossmember and the trans I bet the rear toe-in is pretty severe as well (just the power-train being back so far would impart a lot of toe-in...it also has 1/2" of shims on each side). I will fix it next week!!

[Mwmwall]

Thanks guys. Very helpful info. The owner is checking out the engine number for me and will get back to me. Dash is correct for stick. Any numbers on the engine or trans that tie those pieces to the VIN?

[Mwmwall]

The owner got back to me. Engine code 0228ZF so the car was automatic. May go look at it anyway but I'm on the fence. Anyone have any pictures of what the body cross member modification SHOULD look like. How much space should be between the engine and the rear most sheet metal so I can tell if the correct trans cross member was used.

I can't tell you how much I appreciate the information. Without the code translations and the guidance you have given I could have easily ended up with a potentially unsafe car and not knowing it has been modified.

The car DOES have the transverse leaf spring so the guy used a 64 trans.

[bbodie52]

It is possible that a correct manual transmission crossmember was transferred from a donor car, or that the existing crossmember was modified. There is a lengthy discussion on the conversion process, with some good pictures, on Corvair Center that you might find to be informative. Just click on the link below...

convert to 4 spd.
http://corvaircenter.com/phorum/read.ph ... 029,page=1

[corvair70]

In my youth I took the manual transmission from a 62 monza 4 dr and put it in a 64 Monza 4 dr." Dumb luck" No frame modification I did rig a mount on the leaf spring to fit the 62 differential. At the same time I added a Spyder cam.Don't know how much it may have improved things but I did manage 105 mph when I let off for lack of space
on a favorite divided highway west of the city.
A fun car you could power shift so easily.