SC manual swap into my base 3.8L?

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BONESTOCK

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Hoping this is where it should be posted.

Anyway. I daily a '91 base with the 3.8L. Trans is starting to slip going into OD.
I picked up an other TBird that has a SC w/manual drivetrain.

Can I swap the auto in my daily with just the manual from this SC drivetrain? Will I have to do anything with the computer or can I just leave the selector in neutral or something?

Maybe just easier to swap the whole engine and trans over?
 
It’s actually a pretty much direct swap, the computer in a 91 doesn’t have any auto trans controls so you can run it as is.

Wiring wise depending on the year of the SC you have you might be able to just plug in its transmission harness into your car and have reverse lamps, speedometer and the neutral safety bypassed from the getgo. Otherwise it’s pretty simple to wire in those circuits
 
The neutral safety switch is part of the clutch pedal assembly - the jumper in the dash is removed and plugged into the clutch sensor.

Transmission harness .. plugs right into the auto harness in under the dash.

Otherwise its mostly mechanical parts to swap over.
 
Yes you can swap the trans. Having a complete donor car certainly helps. The only thing that will not be a direct swap from the SC is the flywheel and starter. The SC engine is neutral balanced, and the 3.8NA is 28oz imbalance, so you will need to get a flywheel for a 95 F150 with a 351 and a 5-speed, and then you will also need the F150 starter to match the flywheel. Other than that, everything from the SC will bolt right in.
 
Slight correct from Mike's post: the 95 F150 uses a 50oz imbalance.
See this old thread on the dead site where we discussed this. I went from 3.8NA auto to manual and then to a 5.0.
www.tccoa.com

5 speed conversion

i have a 94 t- bird 3.8 if i got a 90 cougar donar car will everthing bolt in to the 94 body from the 90 car pedels, hydrolic set up ,crossmember , drive shaft ect...
www.tccoa.com www.tccoa.com

Since you have a SC donor, the solution is likely to reuse the SC starter and take SCs neutrally balanced flywheel and have it drilled out for 28oz imbalance at a machine shop. I think this is what I did back in the day.

If you just want to spend money vs paying for machinist work, you can look for a 28oz imbalance flywheel from an older 302 engine AND get a starter that matches the same number of teeth as the new flywheel (likely from the 95 F150). When I went from V6 to 5.0 V8, I kept everything 50z and used 95 Ford F150 flywheel/clutch/starter.


Only the earliest SC engines (89) had an external balance. You can tell if there's a harmonic balancer on the front of the engine.
if your donor is an 1989, you might be lucky and can just swap over the starter+flywheel from the donor since those early SCs used a 28oz imbalance.
www.tccoa.com

91 Thunderbird 5.0L Sport manual T5 conversion, HELP!

Hello like minded individuals, thanks for having me!! I'm going to try to keep the information grouped as nicely as I can, if there are any questions feel free to post them and I will get back with answers as soon as I can. -History of the project so far A number of years ago I found my first...
www.tccoa.com www.tccoa.com
 
MadMikeyL said:
The 5.0 is 50oz imbalance. That’s why I said get one for a 351, which is the 28oz imbalance, same as the 3.8.
Click to expand...
Ahh, I stand corrected.
THAT might be the cheapest swap: 351 flywheel, clutch, starter.
From rockauto
F150 Flywheel - $32
F150 Flywheel Bolts - few bucks
F150 Clutch PP - $77
F150 Clutch bolts - few bucks
Pilot Bearing - ? (I think this needs to be F150 as well)
F150 Starter - $51
 
How difficult would it be to swap the engine over as well? That would definitely be a huge upgrade.
 
KEVIN8989 said:
How difficult would it be to swap the engine over as well? That would definitely be a huge upgrade.
Click to expand...
It would be significantly more work. That would require swapping pretty much everything, engine, trans, rear differential and axles, all under hood wiring, dash wiring. It can be done, but it’s a lot of work. The trans swap can be done in a weekend. And if the car is a daily driver, that matters.
 
Hmmm.. man...good to know this info! Thanks all for the replies.

Doing a full drivetrain swap is also in the cards. I'm not afraid of the work and this car does not have to be a daily. I just like driving it.

Swapped the rear end would be required though?

I was just wondering how easy a swap it could be. The drivetrain I picked up I was told is from an '89 SC. The car this drivetrain current is in though is a '91 LX. So I don't have the original SC.

I'm thinking I'll get the donor car running good. Right now it barely wants to start. Going to start with replacing all the grounds first.
 
Last edited:
MadMikeyL said:
It would be significantly more work. That would require swapping pretty much everything, engine, trans, rear differential and axles, all under hood wiring, dash wiring. It can be done, but it’s a lot of work. The trans swap can be done in a weekend. And if the car is a daily driver, that matters.
Click to expand...
The rear diff and axles are different?
 
SCs and V8s used the 8.8 where most base 3.8s had the 7.5” differential… though some had 8.8s with ABS(there’s a dedicated 7.5 casting for the sensors but Ford seemed to throw 8.8s in when they were short of those). The halfshafts are smaller as well

dDUBb said:
The neutral safety switch is part of the clutch pedal assembly - the jumper in the dash is removed and plugged into the clutch sensor.

Transmission harness .. plugs right into the auto harness in under the dash.

Otherwise its mostly mechanical parts to swap over.
Click to expand...

The neutral safety I was referring to is the one in the AOD, it splits the same circuit the clutch pedal switch does, so if the harness wasn’t available this circuit would have to be jumped as well
 
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