Hi lads can any of you help I need to no if there are any cosworth diffs out there 2wd and 4x4 that are the same rashio,s or very close why I'm asking is I'm running a skyline gearbox in my focos and I can here the diffs working over time and I don't no how long they will take the strain there under see wot it is a 4x4 box works on about 70/30 split this is only a ball park figer and a skyline runs 50/50 split . So when I click the skyline box it to 4x4 they start to fight each uver in 2wd it's all good . I can put any cosworth diff in the car that I won't as I'v got a 7.1/2 rear beam fitter . It's just I'm not very good when it comes the crown wheel and pinions so any help would be fab . O I'v only got a small budget to sort this I'm not the Bank of England lol
Thanks for your help lads

 

A skyline runs variable split depending on pressure to the clutches, are you running a cosworth front diff then and a skyline rear ?

 

Hi mate at the mo cosworth front and rear with the skyline gearbox in the middle . Your right about how a skyline runs it but I can not run the skyline ECU to control the transfer box . I spoke to a chap that dose a lot of work on skylines and he said the front and rear diffs on a skyline are the same rashio . Cosworth, are not the same

 

Yes mate skyline diffs are the same, I didn't realise cossies were different ratio what a Shit idea lol

 

which cosworth diff s are you using coley ?

 

Cosworth duffs are the same ratio front and rear. They are both 3.61

 

At the mo I'v just got standerd 4x4 ones in the car with crown wheels and pin, are in them I don't no with out looking . I would like to run my standard 2wd 3dr diff in the rear as it more up for the job but that might make it worse I just don't no

 

O right well in that case I must have a od diff in then as when I click the skyline box into 4x4 I can here the diffs come under load . I think I will have to get the covers off the diffs soon and see wot they say

 

Hey mate not sure if its relevent to your situation but when i spoke to bara about my supra dif (3.9) and 4x4 box he said id need 3.9 drop gear in the box and an uprated vcd as it would burn out if i didnt

 

The Cosworth uses 3.62 for both the front and the rear diff. The 34/66 is torque split, NOT difference in speed. But I don't know how you would be hearing the diffs. If the diff ratio's are different it's the LSD in the gearbox that will be under strain.

 

Ian, you need to make sure that the front and rear diffs are the same ratio and that the overall height of the wheel and tyres are too otherwise you will wear the plates out in the centre diff when running it in 4x4 mode. Btw, how do you know what torque split you're running? What pressure are you giving the centre diff?????

 

Hi Martin thanks so much for your input in this post all the wheels and tyres are the same size there rex,s old wheel,s
As to wot split it's running I'v only put a resister that I can control the presser with . but I will be putting a presser gauge in the car so I will no Wots being sent to the transfer box and work it out from that . I'v been told that it's 280 psi from the lads on a skyline site . Again thanks for the
Input Martin

 

torque split shouldn't make it feel like its pushing from the rear its only the amount of power supplied not changing and turning speeds of each side of the box.




I had issues with my r33 vspec, so I just ran 12v to the pump and it ran at full system pressure which I think is around 300 psi and just ran full time 50/50 4wd and it felt fine, I cant see how the torque split could make it feel like its pushing or pulling out of sync ?


are you 100% sure both diffs are the same ratio ?

 

Hi lads how do I tell wot front diff I have in the car as I'v got two front diffs in front of me and I can not make head or tail of ever of them . I'v got a rear on the bench and that dose say 3.62 painted on the crown wheel

 

Thanks lads for all your input into this post well there is good news I'v had both the diff covers off tonight and to be onist I was at a bit of a Los but I'v sent a texet to a very good friend and he has told me how to work it out . To witch I'v done and both of the diffs are the same with 47 teeth on the crown,s and 13 on the pinion witch works out to 3.615 . So I'm happy now to no this is good and it's the way the ca will be . Thanks again for every ones input this is wot this site is for and it works very well thanks

 

Is there anyway of running a hydraulic handbrake release with the skyline box?

 

Nice 1 glad you got sorted

 

Hi mark if your on about if the gearbox is in 4x4 and you pull the handbrake then yes all you have to do is put a switch on the lever and wire it in so when you pull the handbrake it turns the pump off and the gearbox gose straight into 2wd then when you let the handbrake go the gearbox will go back into 4x4 in a slit second . I hope that helps you mate

 

Me to mate just got to put the car back togever again lol

 

Question regarding the skyline boxes

Which is stronger? R32 or r33?

What's the difference between the push and pull gearboxes?

Thanks
Marc

 

Hi mate I don't no witch is stronger out of the two of them . The push and pull is how the clutch arm work

 

R33 I've read is better box I can't remember why. There a great box will take 600 hp and abuse no problems as long as not a million miles old knacker box

I have run in the low 7 seconds to 100 mph on vredestein tyres no problems they are a tough box for the money, I'd want a getrag 6 speed now though if I had another there so much better imo and worth the expense

 

Are you running the sand tyre size front and rear? My cousin had a problem with his 4x4 saff when he bought 2nd hand 18in comps as front tyres were 215/35 and backs were 235/35 making the rolling diameter longer on the rears than on the front causing the centre diff to shit itself

 

All the same all round mate we have sorted the diffs mate there the same it must just the way it's going to be . It dose not push are pull from iver end it was just the sound they are making that's all . Thanks for your input mate

 

I'm told the Holenger gearbox is the one to have .
The skyline place tryed to sell me a gear set out of a gearbox and it would go strate into my box for £3,500 second hand he said the gear set new is over £6,000
They run them in 1000bhp skylines on the strip

 

Holinger is the one mate 6 speed sequential but there something like £12k new!

What power and weight is your car mate?

 

I wonder if you need different drop gears or diff if running the 3.9 supra diff that I have, skyline box and std front cossie diff?....I will give Bara a call

 

The box I have bought has a centre push clutch release but the guy that sold it to me said I needed to get the gearbox input shaft macinhed down to accept the cossie release bearing but can I not get a larger clutch release to avoid removing material and the adapt it to the cossie pressure plate?