locker diffs

[goulash]

I was wondering if there is a way for me to check whether i actually have a locker diff on my rx7, and whether it is damaged or whatnot.

The previous owner has the receipt for a locker diff, but i can do one wheel burnouts, so i don't know if its broken or the receipt lies?

move this if ive put it in the wrong forum ;p

[Jay95R33]

I was wondering if there is a way for me to check whether i actually have a locker diff on my rx7, and whether it is damaged or whatnot.

The previous owner has the receipt for a locker diff, but i can do one wheel burnouts, so i don't know if its broken or the receipt lies?

move this if ive put it in the wrong forum ;p

Jack up the back of the car, throw it in neutral and spin one wheel.

If the other wheel spins the same direction then you've got a 1.5 or 2 way, or a welded diff.

If the other wheel spins the opposite way then you've got a normal diff.

Best to do this when the oil in the diff is hot (after a 30+ min drive).

Other than that, pull the cover off it and have a squizz

J

[goulash]

cheers

[Duncan]

one wheel burnout = not a locked diff...

My stocker ran out of "Limited" turning it into a "Slip Diff" which only ever spun one wheel

[LastTemptation]

:wassup:

the easiest way to tell if you have had a "locker" i.e locking device installed in the diff, is to see if it makes a clicking sound when your taking a turn... if it don't, then the diff is normal. If it spins both wheels and dont make sounds, thens its a normal limited slip diff (torsen, eaton locker etc).

I think yours has no locking device.

[Jay95R33]

the easiest way to tell if you have had a "locker" i.e locking device installed in the diff, is to see if it makes a clicking sound when your taking a turn... if it don't, then the diff is normal.

Not all locker diffs are like that.

I've got a 2 way in mine, and I can make a tight slow turn and the diff doesn't make a sound. But give it a bit of throttle while your doing a tight slow turn and then it'll lock up and start skipping.

J

[Kinks]

Jay, interested in specifics on your diff.. it sounds like it suits daily driving as well as enthusiastic driving..

[Jay95R33]

Jay, interested in specifics on your diff.. it sounds like it suits daily driving as well as enthusiastic driving..

I'm not exactly sure what brand it is, although all the mechanics that have driven it have said straight away that it's a 2 way.

The speed of lock up is very oil temp dependant too. First run in the morning (cold oil) and the diff is like a LSD and hasn't got much of lock-up. But once the oil is up to temp it doesn't take too much to lock it up.

Yepp, it's great for daily driving, just ploding around it's almost normal. But give it a bit of throttle and you can have some fun.

J

[NIZR34GTT]

Might be a dumb question.What happens if you break an axle with a locker diff does the car suddenly start going arround in circles ?

[Jay95R33]

Might be a dumb question.What happens if you break an axle with a locker diff does the car suddenly start going arround in circles ?

In theory it should still drive straight....ish...

If an axle snaps, the diff will think that your going to spin up one wheel, so it'll lock the diff and drive the other wheel too.

Mind you, I wouldn't like to drive it like that.... And it would be so easy to bag up the one wheel that isn't snapped !! LOL

J

[Kinks]

If you break an axle with an open diff, I assume the broken side will always turn and you'll be pretty much stranded. With a locker, both sides will still turn and I'd say if you give it any throttle you'll be spinning one wheel like crazy. But I really wouldn't know!

Jay, interesting.. I wouldn't mind a diff that is more like an LSD but doesn't wear out. Previous owner gave the LSD centre to me and said "once you've driven the car a bit i doubt you'll put the LSD back in".. well he's right but tight corners are pretty harsh...

[Jay95R33]

Yepp, that sounds right about spinning up the one wheel with a broken axle

I find the 2 way is so much more perdictable and stable, and in most cases faster.

You can get mini spools and full spools although I don't know excatly how these work.

The other option is a tight LSD. UAS have these for sale on their web site for ~$1200 exchange. I can't comment on them though as I've never tried one.

Tight slow corners take a bit to get used to. But you eventually learn how to drive to minimise the inside wheel skipping. Where ever possible just get the car moving in a straight line first, then turn the wheel (if that makes sence ! )

I remember driving past two police officers one day as i was turning at a set of lights, and it was skipping madly around the corner. The officers had a confused and slightly worried look on thier faces !! So just remember that fully locked diffs are illegal. And to tell you the truth, I'm not sure what the legal standing is on 2 ways etc...

My car passed the rego inspection with the 2 way though.

Can anyone give any info on the legallity of 2 ways?

J

[cul202]

i was in my mates charger, fitted with a minispool, when it broke an axle on a UWS campus. we managed to limp the car back to mine which fortunately was only two blocks away. it wobbled around but the bearing manage to hold the axle in for those 2 blocks.

full lockers (welded, mini or full spool) mean you can only spin both wheels at the same time at the same speed ie no differential action at all. forget about reverse parking with 265's lol...

[Kinks]

Either way I'd really prefer not to break an axle so that I can find out what happens!

Mini spools and full spools have a solid centre so no diff/spider gears. Basically the pinion turns the crown wheel and that's connected straight to the axles. I've got no idea what the difference between a mini and a full is though.

cul: full lockers are fantastic on the open road but as you say, they make city tasks (turning at the lights, out of side streets, and reverse parking) a chore. And yeah, illegal.. I believe you can drive safely with a locked diff in any weather but most people being idiots, it's probably safer to say "you're not allowed"...

Sounds like Jay has the best option, having a locker that unlocks so you can take slow corners is ideal.

[cul202]

yeah i was thinking about mig locking the diff in my old torana until i watched my mate try to back his charger out of my curved driveway... tedious

minispools replace the diff gears in the original carrier.

fullspools replace the entire carrier ie the crown, pinion & external case are all thats left of the original diff. most proper drag 9in diffs run full spools

[stu_r30]

people have lockers in their short nose r200, is there anything available for the long nose r200...(LSD, mechanical etc)...??

[LastTemptation]

Two way is more for track use.. it acts as a brake wen slowing down, like ur still in gear. (engine power slowing down) feels dodgey in the wet.

[Duncan]

I've got a mechanical 1 way diff and it has the same effect, if you are not on the power in the corner it is exactly like a regular diff. If you are on the power more than a little the inside wheel skips (pretty wierd at first).

Makes a huge difference in traction out of corners tho!

Also, I've borken an axle in an open diff car (the race car), it looses all drive straight away - all torque goes to the broken side - looks wierd seeing the speedo at 140 and the car stopped

[SATO GTS]

i had a mechanical locker in my 31 . when on a hoist i could turn either wheel forward or backward while holding the opposite wheel still.

when i tried to turn the wheel's both in the same direction , i could not turn one wheel more then the other. they will turn at the same speed.

if you have a LSD then the wheel will turn at a given breakage point or where the lsd is set to .. Borgwarner LSD are set to around 90foot/pounds of torque.

that means when one wheel is solid on the ground and the other in the air with a torque wrench on the stud's it will start turning at around 90 ft/pounds of force.

if you have a mechanical lsd then the same applies as the above to a set torque .but only when there is a greater force applied through the pinion and onto the crownwheel will the breakage point be multiplied because of the mechanical advantage. eg it may be upto 250ft/pounds of torque to break the LSD effect.