Mustang Transmission Swap

Overdrive transmissions are a great thing. They enable you to significantly improve the gearing and acceleration of your car, while maintaining gas mileage and highway cruisability. Unfortunately overdrives, manual or automatic, weren’t offered in Ford vehicles until the late 70’s. But that doesn’t mean you have to be stuck with the non-overdrive C4’s. C6’s, and manual 4 speeds of the 60’s. Swapping in a late-model overdrive transmission, namely the T5 manual and the AOD automatic, is a straighforward swap for 289, 302, 351 equipped cars. In fact on most early Fords, the swap is so easy it makes you wonder if Ford was thinking ahead. In this article we’ll go over what it takes to swap in a T5 tranmisssion into an early Ford. In future articles we’re go over an AOD swap for early Fords, and also an AOD to T5 swap for late-model Mustangs.

Slight clearancing of the shifter opening in early may be required. We had to do it on our ’67 Mustang, but in a ’65 the T5 lined up perfectly.

Swapping into early Mustangs, Falcons, Mavericks, and Pintos is easy because the hole in the transmision tunnel for the shifter is in about the same spot on all the cars. The swap is also easy for Fox body cars such as the Granada.

For other Fords, namely the full-sized cars, the swap is a bit more difficult because the engine is placed farther forward in relation to the driver. Ford
used modified shifters and/or longer tailhousings to set the shifter back for the original transmissions in these cars. Unfortunately there is no such modification we know of for T5’s.

If your car is currently equipped with a non-overdrive manual transmission (Ford 3spd, 4spd, or Toploader) the swap is as simple as a clutch job, you can use your existing clutch and flywheel, but you’ll need a crossmember and possibly a slip yoke and driveshaft as mentioned below. For cars with automatics you’ll need to first install a clutch pedal and round up the clutch activation parts (either manual clutch linkage or a cable operated clutch.)

We’ve seen the T5 in several Falcons and Comets originally equipped with column shifters. The owner had to punch a hole in the transmission tunnel and fabricate a longer shifter and/or replace the bench seats with bucket seats. Most Ford cars sold with automatic transmissions have factory stamped holes in the firewall for the clutch pushrod or cable. Usually a hard tap from a mallet will knock the stamp out.

For Bronco and Ranger owners, jamesduff.com sells adapters to bolt the T5 to 2.9L and 4.0L engines.

Toploader and T5 dimensions
Transmission	A	B	C	D	F
Ford Toploader (small block)	6.375	13.25	25.375	n/a	5.5
Ford T5	6.9	14.5	24.7	15.4	5.5
Overal length (A+C)	Toploader: 31.75 in. T5: 31.6 in.

Where to find a T5?
The T5 transmission is a manual five-speed transmission manufactured for Ford, by Borg Warner (now Tremec.) The T5 was offered in Mustangs, Thunderbirds, Capris, and possibly other Ford vehicls from 1983 all the way up to 1996, but you have to be careful -there are different specifications for 4-cylinder, 6-cylinder, and V8 cars. What you want is a T5 from a V8 car, ideally a Mustang. The 1983-1989 V8 T5’s are rated at 265 lb.ft. of torque, while the 90-93 T5’s are rated good to 300lb.ft of torque (93 Mustang Cobra T5 is rated for 310 lb.ft.) The difference is in the internal components and also the gearing. See the chart below for gearing differences. The 1994-1995 T5’s are not desirable because the input shaft length and thus bellhousing depth were changed to accomodate the new SN95 Mustang body style. If you do come across one of these dirt cheap the input shaft can be replaced with one from an earlier T5, but it’d have to be a really good deal (read free) to go through the trouble. Finally, we should mention that the T5 is also called the “World Class T5”, but many people incorrectly believe the term World Class refers to a stronger type of T5. All Borg Warner T5’s are considered “World Class”, so don’t rely on that term to indicate the type of T5 you have. The best bet is to find the T5 attached to the car, or with reliable evidence of the car it came out of. If that fails, look for the stamped aluminum tag hanging of one of the tail shaft bolts and use the ID chart to identify the model. Copy the numbers down and call D&D or Hanlon and beg them to tell you what year it’s out of.

While it is best to shoot for the 90-93 T5 due to its increase torque capacity, you shouldn’t pass up a good 83-89 T5, espeically if you’re engine is not heavily modified. We’ve found that T5 strength and longevity is more a factor of its condition and mileage rather than it’s torque rating. A used, high mileage, Cobra T5 will probably shift poorly and give out much sooner than a earlier T5 that came out of grandma’s car. The T5 in Project 11.99 was bought from a wrecked 1990 Mustang 5.0 with 50,000 miles. We’ve had it in the car for nearly five years now, over 400 passes at the strip, and it shifts as crisp as it did on day one.

By the way, always take the bellhousing and block plate if they are available. The T5 swap can be done two ways, using a T5 bellhousing or using an early Ford manual bellhousing. It is much easier and cheaper to use the T5 bell, we’ll explain why below.

What to pay?
Used T5’s can be bought for as cheap as $100 out of a wrecking yard, however we rarely ever see Mustang 5.0’s in public wrecking yards, most of the cars go to specialty dismantelers. You’re better off searching the classifieds and online Ford bulletin boards for guys parting out their Mustang, or perhaps upgrading to stronger transmission wanting to sell the T5 cheap. A fair price for a used, but not abused, less than 80K T5, is between $300 and $500. Any more than that and you should consider buying a rebuilt/refurbished T5 for around $700 from places like D&D or Hanlon. If you want to be extra safe you can buy the T5 new. Both the above sources, as well as Ford Racing Parts and Summit Racing, sell brand new T5 “Z” spec transmissions. The Z spec. transmisison is rated for 330 lb.ft. and sells for around $1300.