Hi
I've a ford Sierra saff 2000e, it has standard rear diff and would like to know what diff to replace it?
Cosworth 4x4 or cosworth 2wd?
Thanks

 

I don't think it really makes a difference. The ratios are almost identical (3.64 for 2wd, 3.62 for 4x4) and the lsd works the same on both. The 2wd 7.5" diff is said to be stronger, but I wonder if that really is the case. Normally the planet gears are the first thing to break and I believe those are the same on the 7 and 7.5" diff. Anyway, both 7 and 7.5" diff will easily cope with the power.

So in the end it depends a bit on what you currently have. The 7" 4x4 diff is probably the easiest fit, as the driveshafts have the same PCD on the flange as standard Sierras with rear disc brakes, while the 2wd cosworth flanges are bigger and require the 2wd driveshafts to go with the diff.

 

Thanks for the reply. Does it make much of a different if there are brake drums at the back rather than disc?

 

Yes, on a drumbrake rear the driveshafts are different and don't fit the limited slip diff. But you can't swap the driveshafts because the arms are also different, so you really need a whole discbrake rear beam.

 

Ok will have to look for a diff to fit or a complete rear end.
Thanks

 

Never seen a 2000e with drum brakes.

 

Maybe someone already pinched the disc brake back axle !

I've seen people do it in the past, swapping it out for a drum axle.

 

When ordering new on 2000e models before Jan 1990, if you did not specify the ABS option then you got 240mm vented front discs and standard drums on the back. After Jan 1990, all dohc models had discs all round and 260mm front discs as standard. I have a June 1989 2000e on the drive that came with exactly that. The rear discs will be 253mm standard or 273mm if Cosworth. Check your fronts as you do not want bigger rear discs than front

To the op, your axle will be a 7.5" diff and subframe. If going to a 7" diff, you will need either spacers and the correct bolts or a whole axle. The lsd did can fit with drum shafts, but they do need modding to fit.

The standard servo and master will be designed for drums, so would advise swapping to the larger master and servo as well.