I grabbed this transmission from fellow GRMer Secretariata. He didn't know what it was at the time. Neither do I. It's now important to identify it to determine it's viability for a Challenge build.
Also, Rob was mentioning some simple ways to extend their life span. What does the hive recommend? (Had to be cheap. Because Challenge)






10-spline input shaft was common on the Ford 2.3's.
Yes, 10 spline. Measures 1.058" O.D. over the splines
Does that confirm it?
Definitely looks like a ford spline.
Ford world class t5
Should be a metal tag on it thats all wadded up and held down by a bolt with your id numbers.
Depending on 4cyl, 6cyl, or v8 changes ratios. And torque rating a little bit. But its what you got, so run with it. Don't hook on the launch pad and it'll live.
NOHOME
MegaDork
4/3/25 7:34 p.m.
Ford. Next question World Class or Early Non-World class?
Figured the gear ratios yet?

Mr_Asa
MegaDork
4/3/25 7:43 p.m.
Mr_Asa said:
I don't see any writing on the bearing up front, so probably not a World Class T5
https://www.moderndriveline.com/how-to-tell-if-your-t5-is-a-world-class-or-non-world-class-version
Look close at the upper left of the picture of the input bearing retainer part number.
Writing and two tone....
Ok, so this won't bolt directly to a SBC bell housing.
Bummer.
I have research to do.
In reply to Indy - Guy :
Find a lakewood bellhousing. Turn input bearing retainer to sbc size. Drill holes in lakewood, weld nuts for new pattern.
If the ID tag is gone, you can pull the top cover off and count teeth to see what ratios you have.
The torque rating is entirely because of the gear ratios, in part because the four, six, and eight cylinder boxes had a different transfer ratio to the countershaft. Higher ratio there puts more stresses everywhere. The gear ratios for the 4 cylinder boxes are pretty horrid anyway, but if it's this or nothing then it's this or nothing.
I have a Ford T5 (V8 box, 3.15 First) and need the Ford case to mate with a Mazda bellhousing adaptor. I would LIKE a Chevy gearset because it's very easy to find a multiplate 7.5" clutch for a Chevy 26 spline input and very hard to find one for Ford. Alternatively I need a clutch disk smaller than 8 7/8" to mate with a Mazda flywheel (or smaller than, I think, 9.5" for a Volvo) and this is also very hard to find. Easy to find for Chevy.
Then I found that almost all Chevy V8 T5s are NWC and I can't use their internals. By the time the WC units came out, Chevy bided their time with the V8s in preparation of just using the T56.
Chevy V8 inputs are 24 tooth and Ford V8 inputs are 23 tooth so I can't just use a Chevy input with the rest of the Ford gearset, too 
You MAY be able to get a 4 cylinder Chevy WC case and use the Ford internals. The trick is, at some point Chevy switched to the Ford bolt pattern so you have to pay attention to what you are getting. I think the S10 T5s still used a Chevy pattern but for sure the 4th gen F bodies used a Ford pattern.
Oh! The other thing is Fords have a much much larger pilot than Chevy. Ford is huge, Chevy is almost exactly the same as Mazda. I had a machinist cut my Ford input down to that size and I rehardened it myself, or at least I tried to. This was to use the Mazda roller pilot, which is important to me if I have the clutch down and the engine running 8000rpm. For you a brass sleeve is probably sufficient. Probably an off the shelf item. (Yep, off the shelf item)
gumby
SuperDork
4/3/25 9:19 p.m.
If it has a tag
https://www.britishv8.org/Articles/Borg-Warner-T5-ID-Tags.htm
If not
http://www.pro-forceperformance.com/t-5_identification.htm
As has been stated, 10sp and Ford case. Neutral safety switch says Fox 5.0 Mustang possibly. Measure the input pilot.
0.590" = 4cyl
0.660" = v8
In reply to gumby :
I don't think it's fox 5.0. All of those were 26 spline IIRC. If it's a WC Ford 10-spline, it's from a Thunderbird Turbo Coupe, possibly an SVO Mustang. If it's non-WC, it could be from a zillion different 2.0/2.3/2.5 Fords.
Indy - Guy said:
I grabbed this transmission from fellow GRMer Secretariata. He didn't know what it was at the time. Neither do I. It's now important to identify it to determine it's viability for a Challenge build.
Also, Rob was mentioning some simple ways to extend their life span. What does the hive recommend? (Had to be cheap. Because Challenge)






Main casting 13-52-065-908 85-91 World Class Ford.
Tail case casting 13-52-066-919 85-90 Ford World Class.
10-spline input shaft. Star bolt on upper left side of case and timken-style plug on nose say definitely World Class, too.
I'm betting 1985-1988 Ford Thunderbird Turbo Coupe. I've bench pressed enough of these, it looked super familiar.
All Ford V8s had the 10 spline input. I am 90% that all Fords period did, but for sure the V8s all did.
In reply to Pete. (l33t FS) :
I'm probably remembering wrong. None of my Mustangs have been anywhere near stock.
In reply to Javelin :
99% certain Ford T5's have 10 splines whether v8 or 2.3. The only time you would see something different is if you stumbled across a gforce gearset equipped box, since they are 26 spline. The only other way to get to 26 spline was to install a tko from Tremec.
Easiest way to figure out which box you have is to place it in first and count revolutions. 2.3 boxes typically are 4:1. V8 2.95/3.35 first gear boxes are obviously closer to 3 or just over.
Looking at the photos, it is most definitely from a fox body platform. Ford never changed how they looked externally. The reverse light switch and neutral sense switch never changed positions.
Came here to say: Ford pattern case, Ford input shaft, world class.
You can probably use an early jeep t4/t5 bellhousing to go from Ford pattern case to SBC bolt pattern.
If you want to get the most power possible thru a T5, install a clutchtamer. The Challenge friendly diy version of the 'tamer is pretty cheap, I see a VH440 cylinder on ebay under $15 including shipping.
Grant
In reply to weedburner :
Do you have a link to more information about the clutchtamer?
gumby
SuperDork
4/4/25 6:47 p.m.
4cyl, likely from a Fox Mustang. None of the Turbocoupe boxes that have passed thru my possession have had a neutral safety switch.
If it's a turbo coupe trans, they are or at least were extremely desirable.
gumby
SuperDork
4/4/25 7:15 p.m.
Pete. (l33t FS) said:
If it's a turbo coupe trans, they are or at least were extremely desirable.
TC T5's used 4.03 or 3.97 first gear ratio sets. The 3.97 were the same as the Mustang(excepting possibly the NSS as noted above).
The only extremely desirable 4cyl Ford T5 I am aware of would be the 3.50:1 gear SVO trans.
In reply to gumby :
Ack, that is the one I am thinking of.