Identifying Different Types of Rear Suspension and Diffs

[Mark (smokey mow)]

Through the years Westfield's have used a number of different types and designs for their rear axle and suspension. whilst there are some variations with different applications and years, for Car engined vehicles these can be most typically be categorised into 4 different types.

Escort Live axle

The Live axle was used in the Pre-Lit, Narrow Body (SE) and Wide Body (SEW) cars. It uses a modified Ford Escort Mk1 or Mk2 (English) axle.

Independent Axle (Westfield/Escort Diff)

This was first used in the Narrow Body (SEI) and the early Wide Body (SEIW) cars. The differential unit is from a Ford English Axle and is housed within a cast aluminium housing off Westfield's own design. The casting is embossed with the Westfield logo on the rear.

Independent Axle (Sierra Diff)

Predominantly found in Wide Body (SEIW) cars and Sierra SDV's. As well as the Ford Sierra's differential The Sierra SDV also uses the driveshafts and rear hubs from the donor with Westfield uprights designed specifically for them. The Standard Modular build kits use Westfield's own suspension uprights and driveshafts.

Sierra SDV rear upright shown below

Independent Axle (Mazda SDV)

The Mazda diff is only found on the Mazda SDV which was released around 2006, the differential unit, driveshafts and rear uprights are taken from the Mk1 to M2.5 MX5.

Other Axles

Sprite/Midget and British Leyland Marina axles have also both featured on early Pre-Lit cars together with the Escort Live axle.

Land Rover Freelander differentials can be found used in the current Bike Engined (Mega) chassis.

The Sport Turbo uses the differential unit from the Mk3 Mazda MX5.

Edited June 17, 2017 by Chris King - Webmaster and Joint North East AO
Corrected Sierra SDV info

[Dave Eastwood (Gadgetman) - Club Chairman]

Freelander Diffs were used in some of the early Duratec engined cars too, before the factory went back to the bigger, stronger Sierra diffs.

 

During Simon and Julian's tour of the areas last year when they visited us, I did ask what the drivetrain plans were, (given supplies of usable Sierra parts), the idea at that point,  was to eventually start to move over to the Mazda diffs in place of the Ford. 

 

(I did ask about the BMW diffs as used by Caterham now, but the chaps seemed sure the Mazda solution was the way forward).

[Rory's Dad]

There has been a long-running thread on Blatchat about BMW diffs.

 

Rory's Dad

[Dave Eastwood (Gadgetman) - Club Chairman]

I'm aware of it, but not relevant to us, (we don't have the de-dion rear suspension).

[peet]

How DIFFicult (pun intended) to swap a live axle over to a Sierra unit? Do extra mounts need to be welded on? Is it an expensive conversion?

I ask as viewing a car with a live axle - thats its only failing for me and would use that as a pricing issue.

Thanks

[Mark (smokey mow)]

How DIFFicult (pun intended) to swap a live axle over to a Sierra unit? Do extra mounts need to be welded on? Is it an expensive conversion?

I ask as viewing a car with a live axle - thats its only failing for me and would use that as a pricing issue.

Thanks

 

As you can see it the pictures the chassis is completely different rearward of the seat back panel, so it would require a lot of fabrication and knowledge to convert from one to the other.

 

IMO it would work out cheeper to buy an independant car if that's what you want.

[M444TTB]

Which BMW diff do the Caterham boys (and girls) use anyway?

[Dave Eastwood (Gadgetman) - Club Chairman]

As a home brew amateur conversion, (and assuming it was done competently), it's hard to see how it wouldn't kill the value of the car.

 

Even if such a conversion was done by one of the big/accepted name businesses that have strong and very trusted reputations in Westfield circles, you'd still hugely narrow the field of potential buyers at resale time.

 

Don't right off the live axle cars till you try one; they make fine, fine, track cars, and they're pretty handy on the road too. It's no where near the disadvantage that it is in many bigger sporting cars.

[Dave Eastwood (Gadgetman) - Club Chairman]

Which BMW diff do the Caterham boys (and girls) use anyway?

 

I forget off the top of my head, but I think it's a One series.

[peet]

Thanks for the reply, I had a better look on a laptop (bigger pix than a phone) and totally agree with you. I used to weld chassis's but with no jig or real reason to do it I wont - it seems a pointless exercise to do.

I was trying to see if a conversion kit was available. It's going to be my first Westy so can live with a live axle - I wont tell the seller that though!

[dhutch]

I cant see the images while at work, but there seems to be two good ones of the english and atlas ford axles at the bottom of this page.

http://www.fordopedia.org/varia/rear-axle-wheel-bearings

 

Google images searches of the above also fairly clearly show images of the two types:

https://www.google.co.uk/search?q=ford+english+axle&tbm=isch

https://www.google.co.uk/search?q=ford+ford+atlas+axle&tbm=isch

 

 

 

Daniel