beginning of syncro in three speed

[Willard M.]

Can someone tell me when the three speed transmission first had syncro in first gear. Reading the article about John Ballard's 67 in the Restorer got me wondering and I couldn't remember when this took place.

Bill #2659

[William C.]

Re: beginning of syncro in three speed

1966 as I recall, at least the parts book has a different part number from '64-65.

[John H.]

Re: beginning of syncro in three speed

Yup, '66 was the first year for the "new" Muncie 3-speed.

[Phil P.]

was the muncie 3spd available in full size cars? *NM*

[Mike McKown]

Re: was the muncie 3spd available in full size car

Chevy II, Chevelle, Full size, Corvette and truck. Probably BOP also. I think this was a Ford design but I really don't remember.

[Chuck S.]

Re: was the muncie 3spd available in full size car

I don't know if the Muncie was ever used in the full size Chevy...maybe as an alternate supplier, or for high horsepower engine options. The 66 Impala I ordered with optional 275 hp small block had a Saginaw three speed.

The synchomesh first gear was one of the marketing features in the 66 Chevy sales literature along a few government mandated safety features (standard seat belts, backup lights, etc). I found that even though the first gear had synchros, that didn't mean you could shift into first at any speed you chose...vehicle speed had to be under about 5 mph if I remember correctly.

[Joe L.]

Re: beginning of syncro in three speed

John-----

I don't think that the fully synchronized 3 speed transmission which first appeared for 1966 was a "Muncie". I believe that it was a Saginaw-manufactured transmission. It was also used in many, but not all, 66-69 passenger cars with 3 speed manual transmissions. All Corvettes with 3 speed manual transmissions during the 66-69 period were the Saginaw unit.

There was a Muncie 3 speed manual transmission. It was classified as a "HD" 3 speed and was used on some 1969 full size Chevrolets, Camaros, Chevy IIs and Chevelles with 350 cid engines or big blocks and on some such applications after 1969. You wouldn't think that there would have been too many of those built (I would think that anyone that ordered a larger engine with manual transmission would also want a 4 speed), but that's what was used if someone did go with a 3 speed for these applications. This transmission was never used in a Corvette, though.

[John H.]

Re: beginning of syncro in three speed

Joe -

That's correct - the "new" 1966 3-speed used in the Corvette was indeed a Saginaw transmission, but it "looked like" a Muncie case and side cover, compared to the much smaller previous Saginaw design.

[Joe L.]

Re: beginning of syncro in three speed

John-----

Yes, the 3 speed, fully synchronized Saginaw did have a lot of the physical characteristics of the Muncie, both the Muncie HD 3 speed as well as the 4 speed.

In a way, I don't understand why GM made the HD Muncie 3 speed. Basically, it was only used for one model year (1969) and saw very limited use for a few years thereafter. It was RPO code "MC1".

[Verle R.]

Re: beginning of syncro in three speed

I suspect the reason they built the Muncie 3 speed was because the Saginaw would not handle the torque of anything larger than a 307.

Small displacement Chevelles received a Saginaw 4 speed and they quickly developed a reputation for being weak. The Saginaw 3 and 4 speeds shared the same case. A few people installed the overdrive from the 3 speed on 4 speed transmissions to make a nice cruising transmission. Recently ran across one of those in a street rod.

Verle

[Joe L.]

Re: beginning of syncro in three speed

Verle-----

The Saginaw 3 speed was used in Corvettes right up to the end of 3 speed manual installations in 1969. For 66-68 it was only available with the 300 hp 327 cid engine, though. For 1969 it was available only with the 300 hp 350 cid engine.