Automatic to Manual...How Much???

[mel_torino]

Can anyone tell me how much work it would take to change an automatic transmission to a manual? I have an older ford model that I want to change into a 5 speed.

Thanks.

>>>>>STOP CAFTA and THE AMERO<<<<<

[ice745]

I once asked a transmission shop this. They responded that you need a donor car of the same make/model/generation that is manual for the parts (because it is impracticle to get all the parts individually that you will need) And they said the amount of work that goes into it, and the cost just makes the entire process impracticle.

I used to have a friend who built custom low-riders. He converted a few auto transmissions into semi-automatic. Basically it was a sequential shift, with auto clutch, and used a new lever. I don't know how he did it or what parts were needed. But most auto transmissions do not have the proper gear ratios for shifting through. So this is generally an impracticle approach as well.

I think unless you have the proper resources and technical minds, it will most likely just be impracticle. I doubt most shops will attempt to approach this job. If you have friends that do track racing, talk to them and see what they say.

[2.2 Straight six]

you're looking at the cost of the transmission plus up to a couple grand in labour. (possibly inc. custom fabb'd mounts if you can't get originals.)

[Moppie]

Originally Posted by ice745

But most auto transmissions do not have the proper gear ratios for shifting through.

eh?

[ice745]

What I meant is, if you move the lever to 1st gear, and get up to speed that you would shift if it were manual, then move the level to 2nd gear, then to drive, then to over drive, you can effectively shift as if it were a manual. But the gear ratios are not designed for this. 3rd gear is mostly used, 2nd gear is used a lot to help accelerate to 3rd gear, 1st gear is barely used and is mostly available for towing/snow.

Where as in a manual transmission the gear ratios are set up more so that you can effectively use all of the gears, all though not so much 1st.

Basically automatics are set up to shift at specific (and low) speeds that the transmission natively shifts at. If you try to intervene and tell it when to shift, and you do it incorrectly because you assume it can work like a manual, you can do some damage.

[UncleBob]

errr.....there's so many cars now that come with manual auto functions these days, I don't think you'll win that argument. Assuming you don't do something really dumb (assuming the tranny will let you do something really dumb), there is no danger. Manual shift kits have been availible from the day auto's were created. Its far from untried waters

I assume the OP wasn't interested in making his auto shift manually though.

[ice745]

Nope, I was just throwing it out there. They are more designed for higher performance cars, whose transmissions are stronger built. I.E. an automatic Camaro's transmission expects more power than a Camry's auto transmission. So the gear ratios are different.

Newer cars, especially audis, transmissions are closer mix of auto and manual. But he said it was an older car.

While cars generally don't let you redline before a fuel cutoff, you can still cause excessive wear to the gears and clutches in an auto trans if you shift faster than it was designed for. And older automatics are generally designed for low speed shifts.

I threw it out there as an alternative, if his auto trans is capable of handling it, because an actual transplant of a manual transmission would be a lot more work and expensive.

[Moppie]

Originally Posted by ice745

What I meant is, if you move the lever to 1st gear, and get up to speed that you would shift if it were manual, then move the level to 2nd gear, then to drive, then to over drive, you can effectively shift as if it were a manual. But the gear ratios are not designed for this. 3rd gear is mostly used, 2nd gear is used a lot to help accelerate to 3rd gear, 1st gear is barely used and is mostly available for towing/snow.

Bullshit. The gear ratios in an auto are designed to progress up and down through the range as vehcile and engine speeds increase or decrease, just like a manual gear box.
The vast majority of Automatic Gear boxes start in 1st, then move into 2nd, 3rd, etc as you accelerate.
When they shift up is dictated by primarily by load, but more modern electronic boxes also take into account throttle position, vehicle speed etc.
Like wise with the down shift.
By shifting them manually, you are simply over riding the gear boxes own in built shift program, be it mechanical or electronic (note, most modern electronic ones will over-ride a bad manual shift).

The gear ratios in an Automatic are designed to work just like the gear ratios in a manual gear box, i.e. provide an efficient delivery of engine power across a wide variety of vehicle speeds.

Some automatic gear boxes are programed to start in 2nd, but they are only fitted to a small number of very high torque engines, and are certainly not the norm. They will still use 1st under high load, e.g hard acceleration, or when carrying a heavy weight.



This is all getting very off topic of course.

[ice745]

Take an automatic, shift it through at 5k rpm each gear like you can do a manual, and tell me it shifts smoothly.

[UncleBob]

you're refering to gear engagement I assume. That greatly depends on the tranny in question. Some are much smoother (ie, slower) engaging than others (and is another aspect you can adjust if you so wish)

[Moppie]

Originally Posted by ice745

Take an automatic, shift it through at 5k rpm each gear like you can do a manual, and tell me it shifts smoothly.

Have done, Iv also run one well past 8,000 rpm and shifted it manually, it still shifted just the same as if it was making an automatic shift.
The mechanism is still the same, just the cause is different.

I think you have a limited understanding of Automatics, and need to improve on it before you try and give others advice.

[curtis73]

Originally Posted by mel_torino

Can anyone tell me how much work it would take to change an automatic transmission to a manual? I have an older ford model that I want to change into a 5 speed.

<<<

Many many thousands, depending on if your car originally was offered with one. If it wasn't, then many thousands more.

[2.2 Straight six]

Originally Posted by ice745

2nd gear is used a lot to help accelerate to 3rd gear.

Yes, that's generally how it goes.