If you are the owner of a 1990 to 1991 Sierra Sapphire, 4×4 Cosworth, the chances are your rubber transmission coupling needs replacing as it looks like this:-
The deterioration of the rubber can lead to complete failure of the transmission coupling, meaning the prop-shaft will come away from the yolk at the rear of the gearbox and, in some cases, cause catastrophic damage to the underside of the vehicle.
The doughnuts are a serviceable item and should be replaced when worn or at intervals recommended by the vehicle manufacturer.
With vehicles manufactured from 1992 onwards (Sierra Cosworths and Escort Cosworths alike), a different, more generic style/make of doughnut was installed. To enable this doughnut to be used, Ford changed the three-pronged yolk to the rear of the gearbox and the front section of the prop-shaft.
There are various solutions to make the later style doughnut fit the earlier cars (1990-1991) which include, changing the gearbox yolk, cutting the spigot from the original yolk, fitting the later version of the front half of the prop-shaft, etc etc. All of which could cost a significant amount of money when you eventually source the parts you need.
Here at M & P we have designed, developed, manufactured and tested a number of direct replacement, prototype spacers/adaptors which allow the later style (and readily available) doughnut to be used, without changing or modifying any of the earlier style transmission components.
The spacer is CNC manufactured from a high-grade, high tensile stainless steel by an engineering specialist whom has a passion for high power and sports cars. The attention to detail in it’s finish is as you would expect.
Set within the spacer is a spherical bearing that matches the original Ford component. This is enclosed with a seal to prevent the ingress of any foreign bodies.
Again – this is a direct replacement of the original Ford component, meaning installation is very easy, even for those less mechanically minded. Fitting instructions will be sent with the kit (spacer/adapter & new Bilstein rubber doughnut) and a video of the installation will soon be available on Youtube.
The latest prototype has undergone a lengthy testing process on a circa 400bhp 4×4 Cosworth without fault.
After 500 miles of regular, hard driving, and even a rolling road session, the spacer was removed from the vehicle and thoroughly inspected for wear and damage – neither of which were present.
This illustrates the whole kit in situ. It retains all of the original fixings 
Inspection time! Prop and doughnut removed to expose the spacer 
Doughnut and spacer show no signs of wear after 500 miles. Copper grease applied for added protection but not necessary. 
In place and ready to go! 
The kit has been re-installed on the car to keep in on the road, which was the main objective of this project – two guys, trying to overcome a problem to keep their Cosworths on the road!
The spacer itself doesn’t come with any official test accreditation (British Standards and the like). It is JUST a spacer. A later style rubber doughnut comes with the kit. This item is manufactured by Bilstein and is used by many vehicle manufacturers on literally hundreds of different models, including BMW.
This being the case, unfortunately, we cannot offer any form of guarantee. A lot of time and money has been invested into this item in an effort to keep our own vehicles on the road along with many other fellow enthusiasts’ cars. This was conceived and executed merely as a personal project which we thought others should benefit from.