Automatic to Manual Conversion
 

Hey guys,

I'm planning on doing a automatic to manual swap this winter but I have a question that I'm hoping you all can answer...

I understand that I will be connecting the auto Iron to the manual bellhousing of the Manual transmission... I have seen that you need a Driveshaft from a manual and a differential and/or a companion plate for the automatic differential.

My question is....

What if I buy a manual Differential and attach an automatic companion plate to that? Could I keep my Automatic Driveshaft with the new Manual Transmission???

Thanks Guys!!

Theo

Anyone

You cannot use an auto driveshaft with a manual trans, if you could then there would be no need to change out the diff or the companion flange.

You have to use a manual trans driveshaft, and from there you have two options for the diff: either a manual trans diff, or an auto diff with a manual trans companion flange.

A few other things to keep in mind:

I do not know if the "yoke" on the driveshaft that goes into the trans have the same number of splines (its been a while since i've done a swap...), but you will need the manual yoke...

the two drive shafts are different lengths (about an 1'' or so...) because of differences in the housing of the respective rear diffs...

the mounting flange is wider on the auto, the bolt pattern is larger...

you will need to mess with 3 main parts for the drive shaft:

• the manual yoke to go into the transmission
• the "shaft" - I would use the one that goes with the rear end u want to use for the length
• the "companion flange" (part that bolts to the diff) that goes with the diff u plan to use...

u could do the auto diff w/ auto shaft and swap out the yoke... or the manual diff w/ manual shaft (untouched! - in theory...)

just make sure ur shaft isn't too short... if you can get a measurement, you might be able to find a shop that can build you a driveshaft to the length you need... and take the yoke and flange you need...

good luck my friend..post pics as you work on it!

I made this swap and i keep the auto diff and yoke!

I drill 4 new hole to acomodate the manuel driveshaft and it work.

I test it at 180kph and have no vibration

i helped a friend swap his and he ended up doing the same thing with drilling the holes... he said it worked for him.

You can use a manual diff or auto, you just need the manual diff flange. The splines from the Auto driveshaft will not go into the tail end of the manual trans plus there is a slight length difference.

You can keep all the auto harnesses by the way as I have posted how to do this in the past on this forum. The only real trick is to make sure you install the Speed Sensor from the Auto Trans into the Manual trans as the tach wont work without it.

What are the benefits of using the auto diff aside from cost of a 5spd diff

better gas mileage on interstate!!! hahaha...

3.90 (auto) vs 4.10 (manual) gears... the auto is slower off the line, but it turns lower RPMs for same speed in the same gear compared to the manual... so it also means that your top speed is higher!

I have the manuel trans speed sensor and it work:scratch: My speedo is off by 2km at 100kph. When i go 100kph, my real speed is 98 kph.

Can you explain why you said the tach wont work?

For your info i have all the manuel wiring harness swap and i still have the auto cluster.

Eric

Did you keep all the stock AUTO harnesses unmodified? What I suggest is only required when keeping all the auto harnesses and gauges.

Like i say in my previous post, i swap all harness wiring from a manuel car. I only keep the automatic cluster and diff. Front main harness,dash harness and "inside firewall harness' replace for manuel harness.

Eric

the differences between the auto speed sensor and manual speed sensor were the length of the wires from the sensor to the plugs... one didn't really have any wires! just the plug... (i dont remember which)...

personally my thoughts on which speed sensor to use is that i think the calcution of speed is done in the cluster, based on the pulses it gets from the speed sensor... so as long as the pulses per revolution between the two sensors was the same, then a manual sensor with an auto cluster and auto rear should be correct...

Did you change the Driveshaft then?

And Thanks a lot guys!! I appreciate the help! This swap will be happening in the winter :D:D

I have a manuel driveshaft. The automatic driveshaft is too long.

If you need advice when you go throught, shoot me a PM :)

First thing, when you want to but your brake and cluch pedal, buy the same year as your car. I buy 94' clutch but they don't fit 93' car without big modification.

I've posted in the past the easiest way to do this swap. I keep all of the factory auto harnesses. You only have to jumper two pins on the large connector that goes to the auto trans. It is the starter interlock you over ride and then use the auto speed sensor and you are set. If you want to wire in the reverse lights and clutch switch you can. If you keep all the auto harnesses the auto speed sensor is a must. My speedo is only 1-2 mph off around 70mph compares to
my GPS. This is the easiest way to swap from auto to manual. Takes less than a minute to do all the wiring that is involved.

What was different?

there's no difference.

Maybe they change the clutch pedal in 95'

Check on this photo of an 93' clutch pedal and watch the black line i made. This represent the angle of an 94+ clutch pedal.(maybe 95')

Also the stud to fix the starter interlock switch is longer and need to be cut to clear the fuse box. The interlock itself is different too and dont have the same connector.

I dont find my pics but i'm sure Fritz of what im saying. I hope i can find a pics to prove my point.

http://i39.photobucket.com/albums/e1...ontrols005.jpg

The part numbers in the '93, '94 and '95 parts fiche are the same. You aren't the only to have a slightly different clutch pedal bracket though. There was a post on RCC about this too. My only guess is that maybe it is a JDM bracket with a USDM pedal.

https://www.rx7club.com/attachment.p...1&d=1288058086