Some of you may say a stupid question we'll see

Im thinking of trying out a bit of a diy diff cooler for the esco's as its gonna get some abuse on the track this year and im now on my 3rd diff since christmas

My question is this I take it you need a pump to draw the oil out of the diff and thru the cooler then back in to the diff ( Would a normal external fuel pump sufice this job or would it clog up with the viscossisty of the oil)

Any input greatfully recieved

Regards Doug.

 

mocal do a oil pump for this job.

 

Any idea how much Lloyd on a bit of a budget now spent rather a bit to much this last fortnight lol

 

they are about 150 quid ,+ 50 for a oil cooler,and 60 for aeroquip plumbing.not too expensive.

 

Thanks Lloyd that don't sound to bad

 

Or get one off a S14 200SX, come with them as standard and shouldnt cost owt.

 

As steve says, the later 200sx have them, you can NOT use a fuel pump, oil is too thick, especially gear oil.

 

The S13 200SX has a diff cooler too, There are loads of people breaking them over on SXOC

 

Ive often considered the whole diff as a swap for a cossie one, people seem to get away with silly amounts of power on them and they are tiny!

 

It's not breaking because of oil temp issues, so you're wasting your time and money fitting on oil cooler, it's breaking because the Ford planet gears are a weak link and can't take the abuse of hard launches etc. If you want to cure the problem, you will have to fit a better diff....

I run a Quaife ATB in the back of mine and have had NO issues what-so-ever. I do 4-6 track days plus two excursions to the Nurburgring every year. Obviously it still uses the OE crown-wheel and pinion (like all the replacement diffs do), but this isn't an issue if the car is not launched everywhere (my Quaife has been in the car for three years!).

 

Ford do a 909 pump for this though ?

 

He wanted a cheap option though mate

 

Ps

Plus i didnt know about that anyway, LOL

 

wasn't meaning price was meaning your not right about the pump.

 

you mean ford do a fuel pump for use with diff oil?

surely then its not a fuel pump, its an oil pump?

 

 

measuring the oil temp will tell you if you need a cooler or not. have you done that?

i can believe that the oil is getting too hot and breaking down which may lead to a failure in some way, but without measuring it and knowing the oil data, you don't know if you're just wasting time and money do you?

 

as mike said oil isn't the issue .......... down to the diff i know that all too well!!!

except the planets didn't give way this thime the CWP did in a BIG WAY!

 

but has that happened because the oil has got too hot at some point (not necessarily when it failed) and has worn the teeth or a bearing or something so that they no longer mesh properly that then leads to that type of failure?

or is it just weak gears or the casing flexing?

 

It's just the planet gears / CWP were never designed for the abuse they are getting. The only thing you can do is get the best second hand matched CWP pair you can find, get them peened and polished, and then fit on a Quaife / Gripper diff. In my experience (tested on a 2wd ATB with 391bhp to the rear wheels), unless it is a gravel spec rally car, the oil doesn't get hot enough to warrent a cooler.

 

there's your answer then - tested

 

Thank you for the reply's guys maybe I should have rephrased the QUESTION.

My first failed diff was due to an inexperienced launch at the pod (AS MIKE SAYS ) smashed the planets to bits and crownwheel

Second diff has failed I think due to over heating on a track day when cold ran fine no loss of traction on the slickes after a few hard laps the inside wheel was spinning up on right hand corners thus giving me no traction place where I have taken it for inspection said it has cooked the plates ?.

Now with out spending mega amounts of money at the moment as ive just forked out for another diff Which might I just add I have no intention of doing any 0-60's or Quarter miles with would a diff cooler of some kind help me in the long run with the plate's failure issue on a track Id love to up grade to an ATB or some other kind of upgraded unit in the future but its just out of my price range for the moment


Regards Doug

 

For now, why not ask bernie what temp is acceptable, then fit a 10 quid temp sender to it, and monitor what happens?

If its goes past what bernie says, fit a cooler and pump

 

Exelent Idea Bat man i'll do that first cheers .

 

You could try having the lock up rates of the diff ramped up. As I said, standard items just aren't designed to take the abuse of track use. Fit an uprated item and it saves you money in the long run.

I was the same as you when I had me Sapphire 2wd - I thought that it would be cheaper to keep buying 2nd hand diffs at Ł250 a pop, 18 months and six 2nd hand diffs later, I wish I'd just fitted an ATB in the first place - cost me twice as much in the long run . I then bought the Quaife and had no more trouble with the car for the next 20k miles with 500bhp and LOADS of abuse .

 

Sounds very feesable Mike

 

A diff pump and cooler is definatly a gooe idea, especially on a track day car with a std diff

WTF are you on about mike ?

there are two problems with heat in a std diff, one is the oil that lubes the gears , if the viscosity is lost then its good bye gears, thus in turn heats up the viscous coupling, if they reach approx 140 deg iirc and it doesnt take very long to do this in summer on a track, then the viscous unit will 'lock' , causing som eof the worst understeer you have ever seen on car, pretty much like driving a car with a welded diff. makes the car handle like shit.

after this unit has locked , you hit a corner, you then make the two tiny undersized planet gears try to work against each other, at a massive force, thus blowing them to pieces.

so who doesnt want to fit a cooler then ?????

yes the 200sx works fine , i have one on my diff, and i also have one for the front diff and the gearbox. also have temp probes fitted to let me know the temps, the best way to do it is make the temp probe switch the pump relays on, thus never over temp, never under temp

dont need a cooler

 

We never saw temps higher than 104°C when we tested an ATB with 391 bhp to the rear wheels . In fact 99.9% of the time, was spent well below that and in double figures. For our application, we then decided it wasn't necessary to fit a cooler. Don't forget that the only heat generated is by the shearing effect of the gears, there is no temperatures being put into the oil like with an engine.

Feel fee to put one on, but I would monitor your temperatures first, as I think you will find that you would need to get on loose surfaces for the temps to rocket for a cooler to be required on a Cossie.

Also, I use a top quality fully synthetic gear oil such as Mobil SHC, which is rated to a lot higher temps than I ever saw...

 

Doug ,
Another thought is to ask yourself why the inside wheel was spinning uncontrollably . Ive seen it a few times that a car badly set up on coilovers becomes light on the inside wheel , this allows the wheel to spin and subsequently cooks the diff ! Ive had this happen to me on one occasion ! Its usually the talk of the paddock that "it lights the back wheels up " and its not the power its just a poor set up .
Corner weight time me-thinks

 

I did probably 30 trackdays on a standard diff... no worries at all. I think something else is wrong as Tony says

Got a plated ZF now and thats supposed to be pretty bombproof. Fingers crossed

 

Plated diffs possibly generate more heat than a Quaife ATB as well?

 

My opinion on this subject....diffs can be damaged equally by being too hot or too cold.....we used to sit a car on stands and rotate the wheels to warm the diffs up......we now also use laminova's to keep the all the car oils incl P.S. oil at an optimum temperature....recently on the Malcolm Wilson rally we were gaffer taping up a car with air cooled diff and P.S. coolers to get some heat into the diffs and P.S......viscous diffs are notorious for overheating with abuse....and yes i'd agreed a plated diff would generate more heat than an ATB....but I think Tony has hit the nail on the head with this problem....the weight distribution needs some attention....probably sprung too hard....

Ian

 

Sounds about right Tony I have got the rear end set extreamly hard any one know a nice setting on AVO's for the rear ?

Front feels good not counted the clicks but arse is on 11 notches and it was set at 3 notches when I ran it on the road and that setting felt way to soft

Regards Doug .

 

tarmac is where ive always seen the highest temps, you will still generate heat on a tarmac surface simpley because of the grip factor and the diff is designed to allow wheel speed changes, in a plates diff or in a crappy atb heat will still be created in the oil, on the loose the car tends to 'skate across' the surface once moving hence the load on the diffs are less than on any tarmac suface, gravel is not know to be a transmission breaker , tarmac is !!

viscous can be a problem to themselves, needed heat to work properly but having to much of which they do generate a massive amount on tarmac causes the problems i discussed earlier to which doug is on about , not plated or atb.