Sn-95 T-5 swap behind 3.8 Cougar/Bird How To.
Well I may be the first to do this swap ever. It does infact work. I figured I would share my time with all of you. Oh and pics will soon follow.
This swap was performed on my 88 Cougar with a 3.8. To start with I will say this was a pretty strait forward swap, almost identical to a T-5 swap behind a 5.0. Here is all the info that myself and others have compiled to do this conversion to your own car.
1. Transmission in question.
A 94 or 95 Mustang with a 3.8 is the donor we are looking for. The T-5 transmission in these 3.8 Mustangs is actually the same T-5 that was behind the 5.0 in 89 and prior mustangs other than gear ratios, it has the same torque rating. The 5.0 90 and up Mustangs received a T-5 with a higher torque rating of around 300 Ft-lbs.
Here is a small chart with gear ratios and torque ratings.
YEAR
MODEL
ENGINE
TORQUE MAX
1ST
2ND
3RD
4TH
5TH
Input shaft length
Input shaft dia. (in)
86-89
Mustang
5.0
265
3.35
1.93
1.29
1.00
.68
7.18
.668
90-93
Mustang
5.0
300
3.35
1.99
1.33
1.00
.68
7.18
.668
92-93
Mustang
2.3
240
3.97
2.34
1.46
1.00
.79
7.41
.59
94-95
Mustang
3.8
265
3.35
1.93
1.29
1.00
.73
7.85
.668
94-95
Mustang
5.0
300
3.35
1.99
1.33
1.00
.68
7.85
.668
So you can see that the Sn-95 transmission is in fact longer than the older fox. Measuring the bell housing’s on the floor comes out ¾ inch difference between the two. Some say ford did this to place the shifter further back in the Sn-95 chassis.
2. Flywheel interchangeability
Through my own research I’ve found what flex plates fit what cars.
83 and 84 3.8’s with Aod’s use the same flex plate.
85, 86 and 87 use the same Aod Flex plate.
88’s use the same Flex plate as all the MN-12 cars and the 94 and 95 Mustang; this must be a change in balance that came with the design of the SEFI 3.8’s.
96 and up fly wheels have a different balance as well.
This limits us to two years only for our flywheel.
It is unknown if a Supercoupe flywheel will work. It should though.
With this information we can see that there were three different 3.8 flex plate/fly wheel balances over the course of the Fox Cougar/Bird.
So without rebalancing, the Mustang fly wheel will only work on the 88 Cougar/Bird 3.8. At this time I am unsure of the actual balances of these engines.
The Mustang 5.0 uses a 157 tooth flywheel and the 3.8 uses a 164. I didn’t actually put my flex plate up to the fly wheel out of the Mustang to see if they were the same size but I believe they were. For some reason the flywheel out of a 3.8 uses an 11” clutch and the 5.0 uses a 10.5” clutch. I’m unsure why Ford did this. Also the flex plate out of a 5.0 is 164 tooth.
Make sure you get the bolts for the fly wheel. The flex plate bolts are too short and lack the required shoulder to locate the flywheel properly.
3. Crossmember.
Your Crossmember can be used without cutting and sliding it. The Sn-95 Transmission pad is further back than the fox T-5. On the Sn-95 the crossmember is even further back than a fox so it uses a steal plate that moves the mount back about 2 inches. You will have to remove this and mount your transmission mount (and exhaust hanger) strait to the transmission. With this setup my mount was dead center in the crossmember.
4. Driveshaft.
With the transmission being ¾ of an inch longer than the Aod in our cars we run into problems with the driveshaft. In my car the driveshaft slides into the transmission and bolts to the axle pinion but there isn’t a safe amount of play for the driveshaft to slide in and out with suspension compression. I will be shortening the driveshaft when funds allow. Since you’re going to have to modify the current driveshaft you may as well use this as an opportunity to upgrade. Use a driveshaft out of an Aerostar, these are aluminum. It will need to be shortened but you will have to do that to your steal one anyway. You will have to use the yoke off of your current driveshaft.
5. Pedals.
Any pedal assembly out of a 79 to 93 Mustang will work. The pedal assembly in your Cougar/Bird is actually stamped with provisions for a clutch but the pieces are missing. The pedal swap is with out a doubt the hardest part of the whole swap. It took me about 2 hours to change the pedals. Lots of hunting for bolts in the dark and you have about 7 switches and relays to unplug in order to remove the column. While you have the column out go ahead and remove the steering wheel and pull out the shift handle and rod for the Aod.
The pedal assembly out of the Sn-95 only bolts the firewall, unlike the fox witch bolts to the column mount and one bolt above the column and into the dash.
6. Clutch Cable
You can use any Clutch cable. I used the one out of the 94 Mustang. No problems at all. The Cougar/Bird even has the holes for the cable bracket drilled into the driver side frame right behind the sway bar mount. The hole in the firewall should be plugged off, just to the right of the booster. It is easiest to mount the cable to the quadrant first before the clutch fork. You will more than likely have to disengage the plastic paw on the quadrant in order to attach the cable to the fork. Once done all you have to do is push the pedal down and let out and it will auto adjust. I see no need to go to an adjustable cable and an aluminum quadrant. I’m not going to be shifting my 3.8 hard enough to have the plastic one deflect.
7. Block Plate
With a 5.0 T-5 swap you have to change the block plate because the starters are in different spot due to the fly wheel/ flex plate tooth count. On the 3.8 you can use your current block plate but you should get the one from the donor anyway. You won’t be able to reattach the torque converter access plate on the T-5 so your fly wheel and clutch will be more exposed to the elements. Also I’m not sure but there may be a problem with the starter hole. But I believe them to be the same. I laid them together to see if the bolt holes lined up, I didn’t notice the hole for the starter being different but I didn’t look very hard.
8. Pilot Bearing.
One of the biggest concerns for this swap was weather the 3.8 crank was properly drilled for the pilot bearing. Well your worry’s are over. A new bearing for a 94 mustang worked just fine. Also note here that since the 3.8 transmission’s input shaft is the same as the 5.0 they use the same pilot bearing. This was verified at Autozone, same part number. Only the 2.3 used a smaller input shaft.
9. Starter
With out a doubt you will have to use the 94/95 starter. I ground down the housing on my starter, but still it wouldn’t fit. This isn’t a problem because again you will have another upgrade. The mini starter spins my car over much faster than the old one ever did. You can easily wire it up by attaching the solenoid wire on the new starter to the larger starter wire. Since you’re not changing the solenoid setup on the fender well power will only be at the starter when you turn the key. Unlike the Mustang that routes power to the starter all the time.
10. Transmission Mount.
Your car will use the same mount as the Mustang. Seems like all ford fox mounts are the same, period.
11. Neutral switch and Reverse light wiring.
The wiring for this swap is easy. On the transmission you have four wires, two for the neutral safety switch and two for your reverse lights. With the change of the Sn-95 Ford eliminated the neutral safety switch on the transmission. You can do one of two things. The easiest way is to wire the neutral safety wires together but the car will start with the car in gear and the clutch pedal not pressed, unsafe! The best way would be wiring the clutch pedal switch up to the neutral safety switch, so the car would only start when you pressed the clutch.
On the left side of the transmission is the connector for the reverse lights. Easy, just wire the pigtail you should have snipped at the junkyard up to the revere light wires.
Oh by the way here are the wire codes.
White/pink stripe and Red / light blue stripe for the neutral switch and Black/ pink stripe and White/ purple stripe for the reverse lights.
12. Exhaust clearance.
Probably the biggest problem with swapping the T-5 into the Cougar was the exhaust. The Cougar’s Y-pipe has catalytic converters on either side. The driver side converter is just in the way of the clutch fork. Actually the bottom of the converter were it meets the rest of the Y-pipe is the problem. You’ll be able to see the offending area when you attempt the swap. I just pounded it down a little less than a ¼ of an inch, then I ground down the contacting area of the clutch fork. I have about a ¼ of an inch clearance now.
The reason the Mustang doesn’t have a problem; its y-pipe comes together after the transmission, not before it.
Now another opportunity for an upgrade, you can snag the factory tube headers off of the 94/95 mustang. They will allow the use of an after market H-pipe designed for the 3.8 mustang. From there you can use a GT take off cat back exhaust, or a new cat back. The stock GT setup will be more than enough for the wimpy 3.8.
13. Speed sensor.
The Mustang uses a different count speedo drive gear than the Cougar/Bird. Unlike the fox Mustang the Sn-95 uses an electronic speedometer. So your speedometer will be off, and no you can’t use your Aod’s gear. I haven’t checked but that’s what other sites say. Your connector will plug right into the Mustang sensor.
14. Additional answers to possible questions.
Without the T/V cable hooked up your pedal will feel much lighter.
The shifter will come through the floor in the perfect spot.
The computer doesn’t need to be changed; besides there is no speed density 5 speed computer for the 3.8.
The Clutch cable goes under the oil pan above the K-Member.
If you get the floor pan shifter boot (not the pretty one, the one under it) it will give you a good idea of what area to cut.
15. Final thoughts.
I did this swap because the 230k mile transmission decided it didn’t want to shift easy anymore. I was able to get all the parts at U wrench it for $230. It was luck because you don’t usually see 94/95 mustangs at the junkyards so needless to say I snagged it all up. My car drives fine with this swap, the junkyard transmission shifts fine.
Enjoy, Claude
Topic: Sn-95 T-5 swap behind 3.8 Cougar/Bird How To. (Read 34139 times)
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