Ford MT75 transmission

The MT75 is a rear wheel drive or four wheel drive gearbox, depending on variant, made by the Ford Motor Company.

It has five speeds and reverse. This was the first Ford production gearbox to have a synchromesh on reverse (so reverse can be selected whilst in slight forward motion). The internal gear assembly in order from front to back as installed on the mainshaft is as follows: 4th, 3rd, 2nd, 1st, Reverse with 5th gear situated at the rear towards the output (propshaft flange), all gears are of a helical cut with the exception of reverse which is straight cut. Refined over time with slight improvement made to the synchro's phasing out single part synchromesh's on 1st & 2nd gear in favour of three part syncro's.

The designation breaks down as

"M" Manual
"T" Transmission
"75" the distance in millimetres between the main and layshaft centers.

Common failures include:

• Mainshafts wear through the hardening (1st - 3rd roller) on the journals resulting in noise
• Front and or rear bearing failure
• Brass Selector forks wear out (jumps out of gear) although this can also be caused by worn dogs & windows on hubs (less common)
• Nose cone / Guide tube becomes loose, loss of oil & burnt out gearbox
• Laygear bearings wear out
• Spigot wear / first motion 4th gear separation / loss of drive

Used in the Sierra and Granada, it came in various flavours for each engine and was used in two wheel drive and four wheel drive (MT75 4x4) versions (four wheel drive in the 4x4 Sapphire Cosworth, Escort Cosworth and XR4x4). This transmission, like the Type 9, is already used in uprated classic cars and hot rods, especially if a Ford Pinto engine, a multi valve 4-cylinder or Rover V8 engine is used. As a 4x4 gearbox, due to the arrangement of the centre differential, it has 34% front and 66% rear torque split as well as a viscous coupling.

It should not be confused with the MTX-75 which is a completely different gearbox for front wheel drive models such as the Mondeo, Ford Escort (Europe) also latterly adapted for use in Jaguars & Transit connect vans.

...
Wikipedia