# 66 Tranny



## chieftugger (Sep 22, 2016)

During a power wash to the tranny while the engine was being rebuilt just recently; noticed on the right side of the tranny there was a yellow 2 letter stenciling (DB) on the 389-4 w/3 speed Hurst shifter with FOMOCO in the casing on the left side. I hearing some rumors of this being a special tranny, WHAT'S UP with this. I purchased her in January 2016 and am learning various and interesting amounts of knowledge about her but I just can't put my finger on this one.


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## GTOJUNIOR (Aug 7, 2011)

DEARBORN 3SPD nothing unusual/special. 

This link/post over on PY should help...
dearborn three speed - PY Online Forums


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## PontiacJim (Dec 29, 2012)

chieftugger said:


> During a power wash to the tranny while the engine was being rebuilt just recently; noticed on the right side of the tranny there was a yellow 2 letter stenciling (DB) on the 389-4 w/3 speed Hurst shifter with FOMOCO in the casing on the left side. I hearing some rumors of this being a special tranny, WHAT'S UP with this. I purchased her in January 2016 and am learning various and interesting amounts of knowledge about her but I just can't put my finger on this one.


Good heavy duty transmission that will hold up to a lot of abuse - have had several. Just like the Ford "top loader" 4-speed minus a gear. The Pontiac bellhousing has the dual bolt pattern for the Dearborn (as it is called by GM) which began on the 1965 Model years. Nice gearing, but the only gripe I have is that when you are street racing and already on a roll at highway speeds, you cannot drop down a gear like a 4-speed to make the car jump away from your challenger - so it makes him think he beat you. Go another round with him from a dead stop and you will wipe the smile off his face as you power out in front of him -my experience. 

"The transmission offerings were revised in 1965. The Muncie 3-speed manual was replaced with a Ford-built Dearborn Toploader 3-speed. This transmission is the strongest manual transmission ever put in a GTO and required a new trans*mission bellhousing to mount it. This transmission offer*ing was retained without changes other than coding until the 1970 model year and the retiring of the Dearborn Top*loader 3-speed manual transmission. The new base transmission was a Muncie heavy-duty 3-speed manual transmission that was related to the Muncie 4speeds."

:thumbsup:


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## geeteeohguy (Feb 2, 2008)

Agreed.....though not as flashy as a Muncie 4 speed, the Dearborn 3 speed is actually a stronger unit. Not a bad transmission at all.


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