Topic: 2.77 or 3.03 3-Speed?

[Pete Bush]

My ’66 Sprint convertible, May 10th Metuchen build date, is identified as having a 3-speed manual transmission. Would that be the 2.77 or 3.03 version? I hear that the 2.77 is problematic. If so equipped, is there a way to increase dependability without sacrificing authenticity?

[JKWilson]

The correct trans would be the 2.77 (unsynchronized 1 st gear). They're also referred to as a "paper" three speed. I know of no mods to increase the reliability of it. If they're not abused they are "reasonably" reliable. A few basic driving techniques can help their longevity. Unfortunately in today's age, not too many people have ever learned or been taught them. They are REALLY basic too. Don't try to speed shift the 2.77 and don't down shift into first unless the car is stopped. A little double clutching when downshifting also helps. Last, don't try to force the tranny into first gear. With the clutch in (which you need to keep adjusted properly!), feather the throttle a little and it will slip into gear quit smoothly.

I lived with one for about 4 years. Thank goodness I worked at a Ford dealership as a mechanic (specializing in manual trannys and differentials). As a young man I gave that little tranny hell. After rebuilding several times, I learned to take it easy. Unfortunately I also taught my girlfriend (now wife of over 25 years!), how to drive a manual tranny car in it. Rack up another 3 rebuilds!

[Pete Bush]

Wow, JK! Your re-build history substantiates my understanding of the little 2.77.

My first step then, is to verify what I actually have in the car. I know the history of the car for the past 22 years, and I know that it had an automatic in it for a time. A 3-speed was back in when I bought it, but I'm not 100% sure it's the correct one for the car.

If the 2.77 isn't correct, I find myself at a crossroad: Do I look for a frail 2.77 replacement, or do I modify the transmission?

Opinion?

[JKWilson]

Honestly I eventually replaced my 2.77 with a '67 3.03 unit. The silly thing is, I rarely drove the car after that and then eventually sold it (I had purchased my '66 GT by then). If you don't have a 2.77 in it, then the choice is obviously up you and what you plan to do with the car. For show purposes (read, originality), and leisurely drives, I'd say stick with the 2.77. Finding one shouldn't prove tooooooo difficult because most folks don't want them. Getting one still in good shape would be hit or miss. The two most important parts are actually the tailshaft and tailshaft housing. They are unique. Other than that you can cannibalize parts from a plane old column shift Falcon tranny. I used to keep several spares laying around for their cluster gear (which was the primary piece that I would find broken/stripped).

The visual differences between the two trannys is VERY obvious! The 3.03 more closely resembles a top loader 4 speed. The 2.77 has a very small case. The whole thing looks tiny!

[Pete Bush]

I understand that the top-load cover on the 2.77 has 4 bolts, compared to the 3.03's 9 bolts.
How about other identifying features or casting numbers? Would anything on the 2.77 make it unique in a Mustang, or was the same transmission used in other Ford model cars? The reason I ask is if the transmission doesn't prove to be the original, is it simply a matter of looking for a 2.77 with an appropriate date code?

[The Kid]

The 2.77 does have 4 bolts on it's cover. As far as identifying it,It more than likely is a 2.77 as the only other real option(talking strictly about 3 spds) is the 3.03,which is a bit of an involved swap. That said, Do you have the ability to take and post a picture of your current trans? I can I.D. A 2.77 from just about any angle. I've actually swapped a few cars from 2.77's to 3.03's,I personally feel it's a worthy swap on any car that is going to be driven.If it's a show car going on and off of a trailer then It would make sense to leave it correct.If you were to decide to swap to a 3.03 and you need some pointers let me know?

[Pete Bush]

As far as pictures, this is about the best I can do without getting the car on a lift. Don't ask me why they painted the thing green!

[JKWilson]

That's a 2.77 Pete. Pic #2 is a good shot. The 3.03 is a wider case. Due to it's relatively puny size, there's no mistaking a 2.77! 

[Pete Bush]

Good!!!  (I think)

Now - where would I find date code information? The warranty tag says 10E and the buck tag says F21.

[J_Speegle]

Good!!!  (I think)

Now - where would I find date code information? The warranty tag says 10E and the buck tag says F21.

There is no reliable (to when exactly your car was built) for 64-66 Mustangs unfortunately. Best guess would be during the 1-4 days following the 21st of June IMHO

[Pete Bush]

I was pouring over the few books I have, and the 1966 Comet, Falcon, Fairlane and Mustang Shop Manual indicates there should be a Transmission Identification Tag fastened to the top upper right extension housing bolt (pg. 6-10). The tag is supposed give year-month-day and shift.

I just looked, and there's a tag on the bottom right extension housing bolt. It says:

HED-BG
6-E-02

HEF and HEG are supposed to be the codes for the 3.03; 6-cylinder and 8-cylinder respectively. Might HED be the code for the 2.77?

June 21st is a good distance from May 2nd, though. But if the 6-cylinders were a slow mover and the reason for creating the Sprint designation in the first place, and with marketing targeting young teenage women (who likely would have preferred the C-4 automatic, is it reasonable to assume that Ford would have amassed a reasonable queue of 2.77 transmissions; dating back some time before the actual build?

[CharlesTurner]

The actual assembly date could be off as much as weeks before or after the scheduled built date code on the warranty plate.  I don't think a trans. dated a couple weeks before the door plate date is unreasonable and in my opinion fits well with most other examples we've seen.

[Pete Bush]

Charles,

On the advice of fellow Sprint owner, Tony Kovar, I purchased Kevin Marti's The Mustang and Cougar Tagbook. It arrived in the mail today. What a great resource! (Thanks for the advice, Tony)

Armed with the new data, I set out to determine the date codes on the engine and rear end; to see how they compared with the transmission. The 6-cylinder engine has a May date (E), which coincides with the May Transmission. But the 3.20 standard transmission rear end has a February, 3rd week date (6BC).

How unusual is that?

[midlife]

HED-BG

My book says that is a 3 speed 2.77 type, 2.76 first gear for a 1966 200 cid engine.