TRANSMISSION
Always the Escort Cosworth’s achilles heel, its 66/34split four-wheel-drive transmission can’t cope with anywhere near the grunt its YB engine is capable of producing. The MT75 gearbox is on its limits at 400bhp (some tuners recommend no more than 350bhp), so if you’re inspecting a modified car be very cautious.
The gearchange should be precise, if agricultural, but if it crunches or is difficult to select cogs (especially on the down change) the synchromesh rings are probably shot – requiring a rebuild.
Layshaft bearings may be noisy, especially in second or third gear; rattling at idle (which sounds like clutch bearing vibration) is early warning of failure. A whining MT75 is on its last legs, and will imminently lose drive altogether.
An Escort Cossie running only in rear-wheel drive may have been converted (losing value in the process) but it could also result from a blown centre differential. Beware of clonking, whining or snatchy diffs.
Vibrations may be from broken propshaft joints or engine/gearbox mounts, while loud clicking is probably a knackered CV joint.
The stock Cosworth clutch will manage 300bhp (or more if driven gently); check for slip by flooring the throttle at around 3000rpm in fifth gear. A sticky cable can make the pedal feel stiff but if it’s leg-breaking the car’s probably been fitted with a paddle clutch – which can be hard work and juddery in traffic.
“...a good setup from a trusted Cossie specialist is crucial ... ask to see the receipts”