# 3 Speed Shift



## SpaceGoat (Nov 9, 2020)

Its been a while since I drove a 3 speed; spolied by my trucks 6 speed, but it seems like my trans is shifting up to third way too fast...I'm in third gear by the time I reach 25mph.
I jut got the car a few months ago and I don't know too much about it's rebuild. It has a strong engine with a Holley SA 770 and low gears in the rear. Also needs a different speedo gear... So I've got a couple tweeks to do, but if anyone could guide me on the transmission shift thing that'd be helpful. 
Takes off fine, barely sees second gear then runs in third just fine. About 3K at 65-75. Also seems to top out at about 85.

What more do you need to know to give some direction/troubleshooting?


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## O52 (Jan 27, 2019)

Year, model, engine, would be helpful to know.


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## SpaceGoat (Nov 9, 2020)

O52 said:


> Year, model, engine, would be helpful to know.


68 GTO, 400


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## O52 (Jan 27, 2019)

With 3:55 rear gearing, second gear should take you well past 65. I suspect you have a 4:33 rear axle.

The three speed manual trans is actually a Ford toploader 3 speed. At the time it was one of the strongest manual transmissions made. In 1964 Pontiac did extensive testing looking for a heavy duty three speed to replace then current three speed. During their testing they severely abused the Ford product but could not make it break. In 1965 it became the standard three speed for the B body cars and optional for the GTO. Known as the Dearborn transmission, it was Buick and Olds also used this transmission In 68 and 69 it was standard equipment in the GTO.
These are excellent transmissions and often outperform a Muncie four speed on the track. 

And yes, I have one too.


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## SpaceGoat (Nov 9, 2020)

O52 said:


> With 3:55 rear gearing, second gear should take you well past 65. I suspect you have a 4:33 rear axle.
> 
> The three speed manual trans is actually a Ford toploader 3 speed. At the time it was one of the strongest manual transmissions made. In 1964 Pontiac did extensive testing looking for a heavy duty three speed to replace then current three speed. During their testing they severely abused the Ford product but could not make it break. In 1965 it became the standard three speed for the B body cars and optional for the GTO. Known as the Dearborn transmission, it was Buick and Olds also used this transmission In 68 and 69 it was standard equipment in the GTO.
> These are excellent transmissions and often outperform a Muncie four speed on the track.
> ...


Thanks. I've been meaning to check/verify my gears. Why would one want a 4:33 rear axle? Benefits?


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## O52 (Jan 27, 2019)

I re-read your opening post. You say that your pulling 3000 RPM around 65-75? If so, then that points to 3:55 or 3:23s. But as I said before, Second gear should take you to 65 easy. Top speed will be in excess of 110 depending upon the condition of your engine. 
If you're only capable of 85 mph and are pulling 3K at 70, the engine needs some attention.


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## Montreux (Mar 8, 2009)

SpaceGoat you’re talking automatic transmission, right? Your car is 50 years old, and modified (Holley), so you need to figure out which transmission you have. It could be a TH400 or TH350. The shape of the pan will tell you which transmission you have. 

TH400 uses a mechanical governor to determine “normal” upshift speed, and a vacuum modulator to modify (raise) shift RPM when the engine is under load. It uses an electric switch to detect full throttle and force a downshift or hold a gear until max RPM. 

TH350 uses a cable instead of a switch for downshift control. 

Either way, it sounds like you have a transmission problem. At constant throttle, shifts should be evenly spaced. If it comes down to a repair/replace decision, 200-4R and 700-R4 are popular overdrive replacements. 

4.33 gears get you across the intersection very quickly, but cruise (highway) RPM will be very high. Overdrive can give you the best of both worlds—quick launch and relaxed cruising. Sounds like your first step is to determine your rear gear ratio. And visit a reputable transmission shop.


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## Montreux (Mar 8, 2009)

Will the transmission hold 2nd if you shift it manually?


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## 3speed goat (Aug 28, 2020)

O52 said:


> With 3:55 rear gearing, second gear should take you well past 65. I suspect you have a 4:33 rear axle.
> 
> The three speed manual trans is actually a Ford toploader 3 speed. At the time it was one of the strongest manual transmissions made. In 1964 Pontiac did extensive testing looking for a heavy duty three speed to replace then current three speed. During their testing they severely abused the Ford product but could not make it break. In 1965 it became the standard three speed for the B body cars and optional for the GTO. Known as the Dearborn transmission, it was Buick and Olds also used this transmission In 68 and 69 it was standard equipment in the GTO.
> These are excellent transmissions and often outperform a Muncie four speed on the track.
> ...


I agree, great transmissions.Have had my 68 since I was in my 20s, now has nearly 160,000, Same transmission, never rebuilt/replaced. Wonder how many were produced? Seldom seen here in Maine, I might have seen 2 others.


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## SpaceGoat (Nov 9, 2020)

Montreux said:


> Will the transmission hold 2nd if you shift it manually?


I'll check that out. I ran it through the His side a week or so ago, it seemed to do just fine. I'll also look into identifying the transmission. Stay tuned. And thanks for the input/info. Appreciate it.


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