First off incase I go with the original cossie, which is stronger? A 2wd rear diff or a 4x4 rear diff?

Also what other diffs are out there I could use? It's gonna be for a fiesta so mounting will be custom anyway, I heard some jags had bullet proof 10.5" diffs so that could be an option?

Opinions please

Cheers
Marc

 

Bttt

 

 

ford 9" fit and forget

 

rod has a jag diff in he's saph,

2wd is a 7.5"

4wd is 7"

2wd is stronger. i had bara rebuild my diff with uprated planet gears nickel plated spacer plates, and uprated vc,

most people will say quaiffe or a gripper, depends how you drive,

if you like to launch then gripper,

but i cant grumble with the bara rebuild especially for the money,

obviously you'll know before you start the build but 2wd and 4wd diffs mount differently

 

Did you find out what your Nm rating was Ronnie - as you have the nickel plates it allows greater than 240Nm ( standard plates limit ) I believe

 

just buy my car ...lol it comes with a almost new quaiffe

 

dont forget if you do go 4wd you need to either match the front diff ratios with the back on or vice versa or have a step off chain to convert the front diff ratio

 

not so straight forward all this diff lark is it

anybody know what jag diff rod has then? is it the 10.5" unit

and id like the 9" ford rear diff but heard there over 3k on there own!

are all the cosworth rear diffs bolt in style driveshafts?

cheers
marc

 

yes 2wd and 4wd have bolt on shafts, but there different sizes and also different lengths

 

The 9" Ford one is certainly around that price from what I've heard.

There was an interesting thread that Porkie started a couple of weeks back about diff options for the 7" rear end that you might find interesting.
I think he decided to get a plate type diff in the end.
There were approximate costs for the different options contained in the thread.
If I understand correctly you need to have some additional work done to fit a Quaife type.

A lot of the big power cars seem to either run a 9" viscous or a plate type diff.
Depends really on what sort of driving you do.
People seem to suggest a smaller viscous one like a 7" will wilt quickly under heat build-up with hard usage if you don't have additional cooling.

Interestingly, Nissan installed factory fit diff coolers on the S13 and S14 200SX road cars - they had viscous limited slip diffs. The cooling was enabled by a speed and temp switch.
I think on the S13 you had to be going over 6mph and have the diff oil over 130 deg C for it to open the stat to the cooler.
On the S14 type the speed factor was increased to 75mph.
Many people seem to bin them as they weren't used in ordinary driving. A few people wired up their cooler switches to a dash light to see if they ever utilised the cooler. A few of the drifters said they only came on after prolonged 'drift' sessions of 20 minutes and 60mph plus slides.
The s14 200SX viscous diff has a higher Nm rating as standard than the 7.5" Ford one. Approx 30Nm versus 24Nm. My understanding is that the higher you bump up the Nm rating on a viscous type, the more aggressive the "locking" will be but by the same token the more front end push you will create ( as with a welded diff ).

If you buy a secondhand 7" or 7.5" Ford one you will find that many of them don't even have the original level of lock as the slicon fluid within gets 'tired' over the years

 

This is the thread I referred to if you want some more info

https://passionford.com/forum/genera...nions-pls.html

 

no mate, i cant find it anywhere,

 

you had a read through, cheers

gripper plated seems very good for price of complete unit etc if i go rwd

 

what is the correct oil to use? as i was told automatic transmission fluid but my diff doesn't seem to lock all the time?

 

not all the jag units measure at 10.5", just some of the crownwheels are 10.5" there ae many units available, from the old 4hu to the newer 4hu, i would speak to TIB if your looking at a cheap diff unit, his seams to do the job.

 

The T5 gearbox uses ATF or automatic transmission fluid as std, the diff should have a good quality 75/90 or Hypoid .

 

sorry, you have not said what sort of power you are going to run?

 

I think Touring car Spares has answered your oil grade question ........however, new oil won't do anything for a tired viscous coupling. That will need reconditioning to get back to the original lock rating if you don't think it's working right.

People like CTS and Bara can do this - CTS were saying about a 4 or 5 week turnaround when I asked recently though

 

cheers

 

can delete this now as see new post

 

might be of some interest to some people, how to fit a mustand 8.8 irs diff, hundreds of ratio options, cheap lsd's, and will take the small ( compared to v8 twin turbo ) amount of power you'll get out of a cossie engine all day long.

http://www.key-ideas.com/DGKurTwo2-040604-8.8LSD.html

search for murkur xr4ti 8.8 and you'll find a few examples of the fitting.