“Week: 4 Shifting Gears: Going from a Automatic to Manual Transmission”

Adam D -

Hello again, this week’s task was the most intricate change I have made to my car so far but drastically changed how my car works. This week I replaced my old automatic transmission with a manual transmission.

 

This process started with me placing the car onto a car lift and then I carefully had to remove the large bolts that held the transmission into the bellhousing. Afterwards, with the assistance of my project advisor I carefully removed the automatic transmission and placed it to the side for a future potential project. Next I had to get a new transmission. I decided on an old Muncie M20 transmission because my dad has a close friend that had one of these in his old Chevy nova and the feeling of shifting was very satisfying. The only problem was that the Muncie was made for Chevy vehicles not Fords like my mustang, luckily my mentor was able to help me find a conversion kit but it still required me to replace everything in between the transmission and engine. This includes buying a new clutch,  pressure plate, bell housing, flywheel, hydraulic throw-out bearing. Along with all of these parts I had to weld together a crossmember to support the transmission.

The replacement started with fixing up the new transmission I bought, however I left this task to my mentor and only assisted when asked to, as transmission assembly is very difficult. After that was done all that was left to do was put the new parts into place starting with a small copper ring that went into the back of the engine port that made sure the transmission stayed seated in the engine. Afterwards I had to take the new flywheel and attach it to the back of  the engine. Following this I had to place the clutch and pressure plate, in that order, onto the flywheel in the correct direction before bolting them down, and lastly I had to attach the new bellhousing which is what holds the transmission to the engine this only required 4 bolts in the corners of the bellhousing and attaches directly to the engine block. Before mounting the transmission, I had to make sure that all the parts were aligned and used a clutch alignment tool. The next part was tricky as it required me lifting the 70lb transmission over my head and inserting it into the bellhousing enough where the spindle was still accessible because I needed to slide the hydraulic throw-out bearing onto the end. The last and most excruciating step was aligning the end of the transmission with the engine port as you can barely see anything and the port is as wide as your index finger. However with much trial and error I was able to slide the transmission into the engine and then all I had to do was bolt down the transmission to the bellhousing, and attach it to a custom crossmember which supports the transmission from the bottom preventing it from falling.

Muncie M20 transmission
bellhousing/ transmission connection point
throw-out bearing(cables) and pressure plate (inner side of bellhousing)
cross member

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Comments:

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    Avy Gagneja
    It’s fascinating to see how many different components had to be replaced, especially with the challenge of adapting a Chevy transmission to fit your Mustang. Now that you’ve successfully completed the swap, how does driving your Mustang with a manual transmission compare to the automatic? Does it feel like a completely different car?
    adam_d
    Ya, besides adding that extra wow factor, I think that it just completes the cars look and feel as automatic cars were much less common when this was originally made so the manual transmission just makes it feel more original and more fun to drive.
    tate_d
    Lifting that transmission over your head and having to align everything is no easy task! I also would have never known there was a conversion kit available for this type of transmission swap. When choosing a manual transmission, was the idea of it being an "anti-theft" device ever considered?
    adam_d
    Actually it was, as this car is some what rare we wanted to make sure it has a lot of safety measures installed within it. For instance, when I replaced the tires I swapped out one lug nut on each tire for a anti theft lug nuts to make sure my tires weren't stolen and I also have plans to eventually add a kill switch to the car making it impossible to turn on unless you know where the switch is.
    adam_p
    This sounds super difficult, Adam. You're technical skill is quite amazing.
    adam_d
    Its fairly challenging but its easier once you work with it for a while.

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