RS Motorsport :: Classic Speed Restored

I don't know about a fierra diff, but the transit Atlas was much heavier than the car ones, very thick wall tubes were used, I am fairly sure the were some different castings for the centre pigs head too

Those Fierra's as far as I can find out were a BW manufactured thing. I assumed they were the small BW 8 bolt diff. fitted in some local TC on 4 cyl Cortina's and other cars of that ilk, but it is not impossible that they were the normal 9 bolt BW fitted behind the local Ford Cortina 200 and 250 sixes.

There was apparently a 5.125 or so ratio available in the Phillipines; lower than anything fitted locally.

ferra-diff

The fierra vehicle has a lot more in common with escorts than most people think. Check this link. http://www.jeepsndgirlsarena.webs.com/fordfierra.htm The fierra axle is basically a type 78 series BTR/borgwarner/dana/spicer diff. They have also been supplied to just about any aussie car you can think of over the last 50 years. The early version were 25 spline and this is what were used in IYK and INB using the Detriot locker LSD and the fierra 5.1 gears. Hopefully John might be able to confirm this. Later models were 28 spline and a lot stronger. Because this type of diff has been used in the states widely in 28 spline form parts for this diff are now common and cheap. $200 US for a 5.1 CW/P in todays money is a bargain. Ratios from 2.5 through to 5.3 and there are even adjustable camber kits available now.

Mik

I got 9 x hilux centers and 4 x RN25 housings for $80.00

Belly

Any 5.3 centres Are they ex mines
David

Mik all you say is true they are a beast of a diff very heavy but bullit proof
IYK had an atlas when delivered bondy soon became sick of breaking axles and centres
so he did the conversion using all the parts that where on the atlas very tough
I am haveing new axles and hubs made at the moment as there is slight wear on the O/S
I think these will be the first replcement in a very long time a very good thing for dirt
way to heavey for any thing else I will post a pic of the axles and you will see what I am talking about

John

Just as a slight side note for my info, couldn't you get away with a diff/axle being slightly weaker on a dirt car as opposed to a bitumen car? The wheels have much less grip so the stresses through the drivetrain would be less? But then I suppose its the slipping-biting cycle that causes the stress.

Thanks for the info John.
Belly, $80 is about all there worth for sCRAP.
Oz, most people would think so, but they didnt fit alloy braces to the atlas axles for no reason. The continual pounding over bumps and the odd off road mishap will eventually bend something at the rear and a bent housing isnt an easy fix in the paddock.

Mik