T-5 Interchange Information
Often I am asked by a person that has picked up a used Mustang T-5
transmission if the one they have found will fit their car. The T-5 has
undergone many changes through the years and yes, many of them can swap. I
will leave the 2005-2010 T-5 out of this, as these T-5s are drastically
These are the 6 basic Ford World-Class swap groups.
If you stay within your group there will be no problems!
|85 through 89 V-8|
|90 through 93 V-8|
|94 through 95 V-8|
|94 through 98 V-6 |
|99 through 04 V-6|
|05 through 10 V-6|
|any 4-cylinder T-5|
When venturing outside of your group these are the Items to look closely
at. If you can find a suitable work-around, have at it!
|The length of the input shaft|
|The pilot diameter of the input shaft|
|Is there a neutral switch on the top cover|
|Is the speedometer sender gear-driven, or all electronic|
|The number of teeth on the internal speedometer gear|
|The location of the cross-member on the tail housing|
Length of the input shaft
There are three lengths of Mustang input shafts.
|83-93 V-8, |
|94-04 V-6 /94-95 V-8, |
The 4-cyl shaft is about a quarter inch longer than the 83-93 V-8 shaft.
The difference is considered negligible, but the pilot bearings are also
The 94-04 input shaft is about 11/16 longer than the 83-93 V-8. A 94-95
style bell housing is needed to go with a 94-95 length input shaft. These
Fox and SN-95 V-8 housings can be swapped, but be careful. Your
aftermarket headers may no longer fit because the clutch forks extend at
different locations! The V-6 Bell housing is NOT
interchangeable with the V-8 because it needs a 164t flywheel and a V-8 uses a
Sometimes the input shaft can be changed to obtain the correct length to
allow for a transmission swap. Remember that the throwout bearing sleeves
are different lengths also...
|If the gear on the input shafts have the same number of teeth, they can be
|Both input shafts must have use the same type of pocket bearing between
the input and the main shaft. COBRA and T5Z inputs use a Caged,
|A World Class input shaft can be put on a non-world Class
transmission as long as you use the World Class type synchronizer ring, and
|A 4-cyl, input shaft will never interchange with a V-8 input shaft because
the tooth count is different. |
|The 85-93 V-8 input shafts will work with the 94-04 transmissions and
vice-versa. (V-8 and V-6)|
|While the 4-cylinder shaft cannot be swapped, a 4-cylinder transmission
can be put into an 83-93 Mustang with the right pilot bearing (Do you really
want to do this?)|
The Pilot Diameter of the Input Shaft
The V-8 pilots are 0.668 and the 4-cyl pilots are 0.590 inches.
Is there a neutral switch on the top cover?
The 86-93 V-8 Mustangs all need the neutral switch.
The 1985 V-8 Mustangs had an "Overdrive Indicator" switch on the
passenger side of the top cover.
Some of the 4-cylinder models within this range have the switch and some don't.
The neutral switches are not on the 83-84 and the 94 and newer T-5's.
An 86-93 V-8 Mustang will run without this switch. Some don't notice its
absence. Others discover that the car surges, or doesn't idle correctly.
Is the speedometer sender gear-driven, or all electronic?
While only the 83-93 Mustangs use a speedometer cable, the speedometer
sending unit is gear-driven from 1983 through 1998. A 99-04 Transmission
will work with a 94-98 Mustang if a signal converter box is used.
The number of teeth on the internal speedometer gear
The 83-89 transmissions have a 7 tooth internal gear and the 90-98
transmissions have an 8 tooth internal gear. This 8 tooth gear is
generally incompatible with differentials such as the 3.73 or the 4.10.
The 06-98 T-45 COBRA transmissions came with a 7 tooth internal gear.
The location of the cross-member on the tail housing
The 99-04 V-6 Mustang cross-member is located a bit further to the rear than
previous models. So, the 99-04 Mustang T-5 tail housing is different and
also uses the all electronic "OSS" speedometer sending unit.
This article was last updated on 07/14/2019