T5 Identification Advice Needed

[Alldegree]

Hello friends,

For as long as I’ve had my car, I’ve noticed that the gearing is really short, as in first gear is good to about 10 mph and then you have to go to second. I knew it had a 3.73 rear end, so I didn’t think much of it.

Then a shop a couple years back mentioned that the input shaft on the transmission is too small, but would still work with the engine. I chalked it up to wear and accepted the fact that I may have to replace it at some point.

Now, having done some research I have a sneaking suspicion that I may in fact have a 4 cylinder T5 bolted to the back of my V8. I crawled under the car to look for the identification tag, and found it had broken off, so all I have is the casting number,
13-52-065-904

I understand that you can’t glean too much information just from the casting number, but a Website I found seems to indicate that it’s a 83-84 non-WC.

I can’t be sure it’s a 4cyl trans without the tag, and rebuilt WC T5s are expensive, so should I have a shop drop it and measure the input shaft to be sure? Or do you guys think it’s safe to assume I have a 4cyl based on the information provided?

Also, if it is a 4cyl transmission, how concerned should I be? I know it’s not rated to handle the torque, but I don’t launch the car from stoplights and I rarely go past 60mph. It’s lasted for about 4 years so far. The car drives fine, it’s just annoying.

Thanks in advance.

 

[Mustang5L5]

1352-065-904 is just the casting number for the case. This was used on a lot of models so not much info there.


From what you state, it does sound like you have a 4cyl T5. Best way to tell is to measure the tip of the input shaft. There are also external differences with the bushings/bearings used that you can tell by looking at the bearing cups up front to determine WC vs non-WC, but ALL mustang T5's were WC after 1985.5. Unless you have an old T5 you should be WC

If it is a 4cyl T5, there's a different pilot bearing you should be running. I beleive it's out of a 2.3L ranger. The 5.0 one is too big and the input shaft will bounce around.

 

[Alldegree]

If it is a 4cyl T5, there's a different pilot bearing you should be running. I beleive it's out of a 2.3L ranger. The 5.0 one is too big and the input shaft will bounce around.

What would that feel like? A vibration? Or a kind of bucking motion? Because that happens sometimes at lower speeds (like in parking lots) I’ve noticed.

Edit: after looking into it, that probably has more to do with my driving than any kind of hardware issue. I need to be more delicate with my throttle/clutch balance it seems.

 

[General karthief]

The bucking at low speed is a different symptom, if the pilot bearing was wrong it would chatter like it was falling out.

 

[Alldegree]

The bucking at low speed is a different symptom, if the pilot bearing was wrong it would chatter like it was falling out.

That’s not happening, so that’s good at least. Maybe the right bearing is already in there.

I’ll be due for an engine rebuild soon, so I think I’ll replace the transmission then. In the meantime I guess I’ll just be sure to go easy on it and hope for the best. Thank you all for your help and advice.

 

[limp]

Don't the 4 cylinder transmissions have a really low first gear in them?? That would equate to the quick rpm's in first gear..

 

[Alldegree]

Don't the 4 cylinder transmissions have a really low first gear in them?? That would equate to the quick rpm's in first gear..

That’s what I figured too, it’s like driving a truck. I’ve actually been starting in second at times just because first may as well not be there. There’s also almost no discernible difference between 4th and 5th. A few hundred rpm at the most.

Driving on the interstate is virtually impossible. I can keep up with traffic, but the motor’s screaming the entire time.

Again, I thought all this was because I had a 3.73 rear end, but now that I’ve done some digging I’m not so sure. One post I read put the top of 1st at about 33mph with that ratio, which sounds way more usable.

 

[General karthief]

Seems as though I remember see'n a chart of trans models and gear ratio
read this....https://www.moderndriveline.com/the-many-different-faces-of-the-t5/

 

[90sickfox]

The pilotvbearing should be a federal mogul s202 bearing. Before my tko600 I had a 4 banger t5. My 306 quickly killed my zspec t5 so I swapped in a junk yard 4 banger t5 so I could move it around the shop. That turned into many years of beat on life behind my nitrous 306, 347, and behind my current turbo 331. Transmission still shifts like new. Wiped second gear on a factory v8 t5 with the 306 before the z spec. I've broken more than a few t5s over the years but this 4 banger one will not die. I thought doing turbo pulls would finally kill it. Only thing I got was clutch slip at 8psi.....way over the 300ft pound mark. The gearing in a v8 t5 feels better 1st through 3rd but 4th is the same 1;1 ratio. Cruising wasn't an issue and I also had 3.73 gears.

 

[Alldegree]

Seems as though I remember see'n a chart of trans models and gear ratio
read this....https://www.moderndriveline.com/the-many-different-faces-of-the-t5/

This is enlightening, thank you. How rare are those T5Z units the article talked about? I had never heard of them.

 

[Mustang5L5]

That’s what I figured too, it’s like driving a truck. I’ve actually been starting in second at times just because first may as well not be there. There’s also almost no discernible difference between 4th and 5th. A few hundred rpm at the most.

Does sound like a 4cyl T5

4th gear is 1:1 in all the T5's,

5th gear in the V8 is 1:0.68 (excluding the Z-spec) but the 4cyl is 1:0.79, so it would feel like almost no RPM drop at all.


1st gear in the 4cyl box is 3.97, vs the V8's 3.35.

 

[Mustang5L5]

This is enlightening, thank you. How rare are those T5Z units the article talked about? I had never heard of them.

You can buy them. They were never factory equipped

Tremec Super Duty T5 5-Speed Transmission | Modern Driveline

Tremec super duty T5 5-speed transmission overdrive 1352-0251 2.95 first .63 OD. We are five and six-speed conversion specialists. Call us at 208-453-9800.

www.moderndriveline.com

 

[FoxChasis]

Is there a (partial) VIN stamped on the case? That would tell you what it is out of.

 

[85GTStangGuy]

4th gear is 1:1 in all the T5's,

5th gear in the V8 is 1:0.68 (excluding the Z-spec) but the 4cyl is 1:0.79, so it would feel like almost no RPM drop at all.

I'm not sure if I agree with that .... or am I missing something? Could you expound on that please?

As an example, if the engine was turning 3000 rpm in 4th, then a .68 ratio in 5th would give 2040 rpm. If using the .79 ratio in 5th, then the resultant rpm would be 2370. To me, both of those are appreciable drops in engine speed, in relation to 3000 rpm. Neither of those "would feel like almost no RPM drop at all". Again, imo.

 

[Mustang5L5]

Sorry, poorly worded on my part. I guess what I should have said was the 0.79 ratio would feel like a smaller RPM drop compared to 0.68.

I'm used to the 3000 to 2000 RPM drop with a 0.68 T5, so only dropping 700RPM would feel "weird" to me.

 

[85GTStangGuy]

Sorry, poorly worded on my part. I guess what I should have said was the 0.79 ratio would feel like a smaller RPM drop compared to 0.68.

I'm used to the 3000 to 2000 RPM drop with a 0.68 T5, so only dropping 700RPM would feel "weird" to me.

No problem. I see what you're saying. Just wanted to make sure I wasn't missing something.

 

[Potomus Pete]

Do you guys think our T5's are World Class. Amature question

 

[limp]

Do you guys think our T5's are World Class. Amature question

For sure.....

 

[Alldegree]

Is there a (partial) VIN stamped on the case? That would tell you what it is out of.

Where would that be? I stuck my phone up and around it taking video and all I managed to see was the casting number.

 

[AeroCoupe]

From an older thread on here: