It was a 440 six pack car... Hemi 18 spline 4 speed , 9 3/4 dana rearend
T5 Identification Advice Needed
- Thread starter Alldegree
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Beautiful. Textbook example of a “muscle car.” Chrysler co. was doing such cool things back then, I don’t know what happened. They seem to have struggled ever since Iacocca left and Daimler took over. Too much accounting, not enough engineering.
Don’t get me wrong, I loved the hellcats. I think they’re all guaranteed future classics, I just wish the rest of their lineup was half as interesting. Right now, Jeep and Ram are carrying the company, Dodge is about to have a make-or-break identity crisis with the new electric charger, and I really don’t know why Chrysler (the division) still even exists. It’s sad.
The gas shortage ( 74 ) changed everything and the big three US carmakers were unprepared for it...
Gas doubled and tripled in price, Gas stations were OUT of gas, had no gas to sell and the government was telling us that it was going to get worse ( sound familiar?).... The smaller honda's, Datsuns, and toyotas stepped right in..
Ah, the infamous malaise era. I’m glad I got to skip that part of history.
American manufacturers had a bit of a comeback in the 80s though, right? I mean the K cars sold well and on the performance front there were some pretty interesting turbo offerings from the big three in addition to the V8 Camaros and mustangs.
I see what you mean though. My entire family has driven Japanese cars for the past 20 years, though many were actually assembled here in the states.
Alright, so I jacked up the rear end and turned the wheel.
1 wheel rotation = about 3 3/4 driveshft rotations
That means I have 3.73s, right? Since it's 3.73:1?
Not sure where that leaves us, but at least we know that part of the equation.
1 wheel rotation = about 3 3/4 driveshft rotations
That means I have 3.73s, right? Since it's 3.73:1?
Not sure where that leaves us, but at least we know that part of the equation.
You need to verify which drive gear you have on the output shaft of the T5. Once you have that then you can figure the correct driven gear that goes on the VSS. With 3.73’s and a 275/40R17:
6 tooth drive - 17.57 tooth driven
7 tooth drive - 20.5 tooth driven
8 tooth drive - 23.43 tooth driven
What strange is you are saying the speedo is reading 60 mph at 2800 rpm in 5th gear.
With the above gear ratio and tire size you should be seeing the following:
Right at 2300 rpm with a 0.79 5th gear ratio
Right at 1990 rpm with a 0.68 5th gear ratio
Something isn’t right for sure. Pretty sure I didn’t solve anything g here but if the rear gear ratio is correct then you would have to be almost 1:1 to get close to 2800 rpm so it would be 4th gear.
6 tooth drive - 17.57 tooth driven
7 tooth drive - 20.5 tooth driven
8 tooth drive - 23.43 tooth driven
What strange is you are saying the speedo is reading 60 mph at 2800 rpm in 5th gear.
With the above gear ratio and tire size you should be seeing the following:
Right at 2300 rpm with a 0.79 5th gear ratio
Right at 1990 rpm with a 0.68 5th gear ratio
Something isn’t right for sure. Pretty sure I didn’t solve anything g here but if the rear gear ratio is correct then you would have to be almost 1:1 to get close to 2800 rpm so it would be 4th gear.
Given the discrepancy with the math a couple more questions.
Your RPM reading - is it on the factory tach or some other tool?
Speed - read off speedo or GPS?
2800 rpm in 5th, even with a 4 cyl T5 (0.79 5th) would be 4.56 gears in the rear.
Just looked up a list of T5s and ratios online. I found a couple interesting choices:
- A bunch of '80s S10 T5's have a 0.86 5th gear.
- A few pre-87 Mustang T5s had a 0.85/0.86 5th gear. (info taken from BritishV8.org)
This is where the tag on your trans would be very helpful. A pic of the tag on one of mine sitting on the shelf...
Second row starts with 1352-xxx. In the above case xxx is 238. To me, that is the most important info when identifying a T5.
Your RPM reading - is it on the factory tach or some other tool?
Speed - read off speedo or GPS?
2800 rpm in 5th, even with a 4 cyl T5 (0.79 5th) would be 4.56 gears in the rear.
Just looked up a list of T5s and ratios online. I found a couple interesting choices:
- A bunch of '80s S10 T5's have a 0.86 5th gear.
- A few pre-87 Mustang T5s had a 0.85/0.86 5th gear. (info taken from BritishV8.org)
| 1352-018 | Ford 1983-84 T-Bird/Mustang 2.3 L4 Turbo | C | 3.76 | 4.03 | 2.37 | 1.49 | 1.00 | 0.86 |
| 1352-034 | Ford 1983 SVO Mustang 5.0 V8 | C | 3.39 | 4.03 | 2.37 | 1.49 | 1.00 | 0.86 |
| 1352-067 | Ford 1984 SVO W/Hurst 2.3 EFI TC | P | 3.76 | 4.03 | 2.37 | 1.49 | 1.00 | 0.86 |
| 1352-154 | Ford 1987 Mustang/Capri 2.3 L EFI WC | X | 3.70 | 3.97 | 2.34 | 1.48 | 1.00 | 0.85 |
Second row starts with 1352-xxx. In the above case xxx is 238. To me, that is the most important info when identifying a T5.
Given the discrepancy with the math a couple more questions.
Your RPM reading - is it on the factory tach or some other tool?
Speed - read off speedo or GPS?
2800 rpm in 5th, even with a 4 cyl T5 (0.79 5th) would be 4.56 gears in the rear.
Just looked up a list of T5s and ratios online. I found a couple interesting choices:
- A bunch of '80s S10 T5's have a 0.86 5th gear.
- A few pre-87 Mustang T5s had a 0.85/0.86 5th gear. (info taken from BritishV8.org)
1352-018 Ford 1983-84 T-Bird/Mustang 2.3 L4 Turbo C 3.76 4.03 2.37 1.49 1.00 0.86
1352-034 Ford 1983 SVO Mustang 5.0 V8 C 3.39 4.03 2.37 1.49 1.00 0.86
1352-067 Ford 1984 SVO W/Hurst 2.3 EFI TC P 3.76 4.03 2.37 1.49 1.00 0.86 This is where the tag on your trans would be very helpful. A pic of the tag on one of mine sitting on the shelf...
1352-154 Ford 1987 Mustang/Capri 2.3 L EFI WC X 3.70 3.97 2.34 1.48 1.00 0.85
Second row starts with 1352-xxx. In the above case xxx is 238. To me, that is the most important info when identifying a T5.
That’s 2800 on the factory tach
60 mph on a gps speedo
There is no tag, I do however still need to get the rest of that VIN on the side. I’ll see if I can get that for you guys tomorrow.
I don’t really know what’s going on either, at this point I’m tempted to just have a go at dropping the gearbox and cracking it open just to figure it out once and for all. I’d have to count the teeth, right?
Mindseye007
Active Member
Don't forget the 360 interceptor in the 1979 Chrysler Newport they were fast . My friend had one we raced a foxbody 5.0 at a set of lights and pulled away from him at the next lights his face was priceless looking at us saying wtf lol
There’s something really special about large vehicles that are faster than they have any right to be.
Even today, I’m pretty impressed at what manufacturers are able to make a 5000 lb family SUV do. Those twin-turbo Explorers are pretty darn quick.
Large?? These cars were considered " midsize" back in the day... LOL
I hadn’t thought about that, but you’re right. I did some research, and a Continental from that era weighed close to 6000 lbs, so I guess compared to the largest vehicles back then a 4000 lb Newport would be considered “midsize.”
Ok, I scrubbed the stamping with a wire brush and here’s the result:
I can make out FF132202
Which means the trans came from a car made in Dearborn (a mustang) in 1985 and that it was the 32,201st unit of that car to be made (1985 started at 100,001).
With that, we have a number of possible combinations, but here’s what I’ve come up with so far: 1FABP2???FF132202.
There aren’t any partial VIN decoders I could find apart from the one on NHTSA’s website, and even then it doesn’t tell me anything I don’t already know.
Any ideas on where to go from here? I could just start plugging in every possible combination and record the results, but there’s a lot.
Edit: I guess it doesn’t really matter since we know it’s an 85 mustang transmission, so we only have 3 options. Neither of them make sense with the numbers I’m seeing though, so I’m wondering if my tachometer is off?
I can make out FF132202
Which means the trans came from a car made in Dearborn (a mustang) in 1985 and that it was the 32,201st unit of that car to be made (1985 started at 100,001).
With that, we have a number of possible combinations, but here’s what I’ve come up with so far: 1FABP2???FF132202.
There aren’t any partial VIN decoders I could find apart from the one on NHTSA’s website, and even then it doesn’t tell me anything I don’t already know.
Any ideas on where to go from here? I could just start plugging in every possible combination and record the results, but there’s a lot.
Edit: I guess it doesn’t really matter since we know it’s an 85 mustang transmission, so we only have 3 options. Neither of them make sense with the numbers I’m seeing though, so I’m wondering if my tachometer is off?
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I am pretty sure that the Motorsport transmissions were not stamped with a partial VIN being they were not installed in a car as they were bought aftermarket. So with that a T5 installed in a 1985 Mustang GT 5.0 would have the following gears:
1st 2nd 3rd 4th 5th Reverse
3.35 1.93 1.29 1.00 0.68 3.15
It would have come with a 7 tooth drive gear on the tail shaft.
What car is this installed in and is it a factory tack or aftermarket?
1st 2nd 3rd 4th 5th Reverse
3.35 1.93 1.29 1.00 0.68 3.15
It would have come with a 7 tooth drive gear on the tail shaft.
What car is this installed in and is it a factory tack or aftermarket?
It’s installed on an 86 GT with a factory tach.
I don’t know what drive gear is on the tail shaft, and I don’t have a jack to drop it and check at the moment. I can certainly rent one if it comes to that.
I think my timing light has an RPM function on it. I’ll use that to see if my tach is off at idle, and I’ll also hand measure the rear tire height since somebody here mentioned there’s some variation.
Stock ignition or aftermarket? If it is an after market then you need an adapter to get the stock tack to work. I am not sure if the stock tach would simply not work or would not read correctly but I know you had to get one of two adapters based on how you were triggering the tach.
Hopefully your timing light does have an RPM function and that will tell the story real quick.
You can tell what drive gear is in the transmission by removing the VSS and shining a good LED flashlight in the hole and look in there with something like a dental mirror. The yellow gear is obviously yellow and the 8 tooth translucent green/yellow one shows really well with an LED light source.
This is what the 8 tooth looks like:
This is what the 7 tooth looks like:
Something it definitely whacky.
Hopefully your timing light does have an RPM function and that will tell the story real quick.
You can tell what drive gear is in the transmission by removing the VSS and shining a good LED flashlight in the hole and look in there with something like a dental mirror. The yellow gear is obviously yellow and the 8 tooth translucent green/yellow one shows really well with an LED light source.
This is what the 8 tooth looks like:
This is what the 7 tooth looks like:
Something it definitely whacky.
Alright, I took out the VSS and shot a picture down the hole and I have more questions than answers:
There’s obviously a gear in there, but I don’t think it’s the driven gear since it’s a toothed gear rather than a screw. Am I just looking at it from the wrong angle?
Also did a trans fluid change while I was down there, car shifts a lot smoother now which is great.
I’m going to see what I can find out about that rear wheel height measurement.
There’s obviously a gear in there, but I don’t think it’s the driven gear since it’s a toothed gear rather than a screw. Am I just looking at it from the wrong angle?
Also did a trans fluid change while I was down there, car shifts a lot smoother now which is great.
I’m going to see what I can find out about that rear wheel height measurement.
Ok, got the tire diameter from circumference using a rope:
I think we can call that 79”
With that, we do 79/pi to get a diameter of
25.146”.
Also used my timing light to check RPM at idle, engine settled to about 850 RPM, and here’s what my tach looked like:
I’d say the factory tach reads about 100 RPM fast.
I’m going to list what we know right now, because I feel like I’m going crazy trying to figure this out:
Tire height = 25.146”
Diff gear = 3.73
Adjusted RPM at GPS rec’d 60 MPH in 5th gear = 2700
According to Motor Trend, the formula for speed from RPM and gear ratios is as follows:
(RPM * Tire Dia.)/(Trans Rat * Rear End Rat * 336)
So our formula would be 60 = (2700 * 25.146)/(X * 3.73 * 336)
67,894.2/1,253.28X = 60
54.173/X = 60
54.173 = 60X
X = .90
So my 5th gear ratio should be .90:1
The only factory T-5 from Ford that even comes close is the one from the 86 mustang 2.3 at .85:1. If this is the correct transmission, my guess is the VIN indicates it was made in 85 for the 86 model year.
Either that or somebody in the past rebuilt it with a weird custom gear ratio.
I’ll try to get the ratios for the other gears and see if there’s a pattern to follow that might line up with a factory transmission.
I think we can call that 79”
With that, we do 79/pi to get a diameter of
25.146”.
Also used my timing light to check RPM at idle, engine settled to about 850 RPM, and here’s what my tach looked like:
I’d say the factory tach reads about 100 RPM fast.
I’m going to list what we know right now, because I feel like I’m going crazy trying to figure this out:
Tire height = 25.146”
Diff gear = 3.73
Adjusted RPM at GPS rec’d 60 MPH in 5th gear = 2700
According to Motor Trend, the formula for speed from RPM and gear ratios is as follows:
(RPM * Tire Dia.)/(Trans Rat * Rear End Rat * 336)
So our formula would be 60 = (2700 * 25.146)/(X * 3.73 * 336)
67,894.2/1,253.28X = 60
54.173/X = 60
54.173 = 60X
X = .90
So my 5th gear ratio should be .90:1
The only factory T-5 from Ford that even comes close is the one from the 86 mustang 2.3 at .85:1. If this is the correct transmission, my guess is the VIN indicates it was made in 85 for the 86 model year.
Either that or somebody in the past rebuilt it with a weird custom gear ratio.
I’ll try to get the ratios for the other gears and see if there’s a pattern to follow that might line up with a factory transmission.
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