All this snow has got me thinking about my car again, when I bought it in august I had a full service done at a Vauxhall main dealer I used to work at (still get stafff discount and I know they'll do a good job because its mine! all genuine parts though). When it was on the ramp I remember turning one of the front wheels and the other turned the same direction. The only time ive known this is with an LSD, ive searched the net but cant find much about it except a couple of things about an electronic diff? Have i imagined the whole wheels turning the same direction thing or do they have some kind of fancy diff fitted, seems to have quite good traction in the snow!

The easiest way to tell is to jack the car up again and physically stop one wheel from turning, then try and turn the other wheel, if it can be turned then it is a normal diff, if however once it is turned (it will require a bit of effort) the other wheel breaks free from being held then there is some sort of LSD in there.

This can also be performed by putting one wheel on a set of rollers, then try to drive off, if it drives off the rollers with no effort then a LSD is present, this is the method that many car clubs use (or used to at least) to check for an LSD in PCT's (production car trials)

HTH

Brap brap as the youngster say these days ........... http://briskoda.net/forums/topic/182391-vehicle-specific-information-and-vin-data/

Brap brap as the youngster say these days ........... http://briskoda.net/forums/topic/182391-vehicle-specific-information-and-vin-data/

Nice one fatmo! I was just about to link to my thread yesterday too!

It's a normal diff as standard, but the car uses a system called EDL to kinda simulate having an LSD, by breaking the spinning wheel. Clever really, and should help in the snow....

It's a normal diff as standard...

Yep, they look like the one of the left:

That ones from a 4x4, but basically the same. Standard open diff. Fairly crude design.

( the one on the right is the standard rear diff from a 4x4 )

For comparison, these are the replacement Peloquin units:

Either way, unless the car was "running" while on the ramp I can't see how both wheels would have turned the same way when on the ramp.

If the car was off, the EDL would have been off, so surely you'd just see a normal diff functionality?

Tom

Those pictures make me moist snow_muncher! I love big bits of engineering metal!

I've got two unused Quafie LSD's on my kitchen counter right now, acting as expensive ornaments. Unfortunately they are for a Land/Range Rover with 10 spline shafts, so not much good for a Skoda! I should ring Quaife and ask if they'll part ex them for an 02J LSD!!

Either way, unless the car was "running" while on the ramp I can't see how both wheels would have turned the same way when on the ramp.

If the car was off, the EDL would have been off, so surely you'd just see a normal diff functionality?

Tom

Thats what I was thinking, Iam sure engine was off and when i spun the drivers wheel the passenger wheel rotated the same way, Iam sure I didn't imagine it but might have to jack it back up and re-check when its a bit warmer! Wouldn't have expected anything other than a standard diff with it being a diesel I must be wrong!

Edited 1 December, 201015 yr by BIGMIKE1

As Gizmo68 states, Without resistance, both wheels will rotate together.

I've got two unused Quafie LSD's on my kitchen counter right now...

If you don't need them for a LR Disco/Offender, won't they sell like hot-cakes to LR folks ?

Sell them and get a Peloquin 02M 498 005A and an O2M gearbox :yes:

It's a normal diff as standard, but the car uses a system called EDL to kinda simulate having an LSD, by breaking the spinning wheel. Clever really, and should help in the snow....

As I understand it, my 4x4 has standard diffs and electronic diff lock (EDL) on the rear. Therefore, to lose all drive I'd need to lose one front wheel and both back ones.

As I understand it, my 4x4 has standard diffs and electronic diff lock (EDL) on the rear. Therefore, to lose all drive I'd need to lose one front wheel and both back ones.

No EDL is a function of the traction-control element of the ABS/ESP system.

It has no mechanical components, but instead uses the front brakes to try to reduce slippage on the front wheels (as per Bodge's thread).

The haldex drive train consists of two mechanical diffs, one being on the gearbox, another being on the prop-shaft before the Haldex clutch system.

The haldex clutch system operates another diff-type device which shunts the power to the left/right rear wheels, and controls how much power it lefts through.

The haldex's computer links into the ESP computer to ensure they don't work against each other.

No EDL is a function of the traction-control element of the ABS/ESP system.

I didn't think what I said contradicted anything in Bodge's thread, except that I thought it was only applied to the rear axel (remember mine is driven when the Haldex chooses to engage) - perhaps I was mistaken and it's applied to the front or both axels. (I understand the Haldex is an electronic clutch - didn't mean to suggest any permanent linkage between the front and rear.)

EDIT: Just found this on Wikipedia, which - assuming it's accurate - means EDL applies to the front axel but not the rear. I stand corrected.

On all transverse engine cars with the Haldex-based four wheel drive system, the EDL only controls front wheels, and not the rear.

In that case, my original statement should have read: in order to lose all drive I'd need to lose both front wheels and one back one.

Edited 1 December, 201015 yr by will_

OK, people seem to agree that it's a standard diff, as demonstrated by the nice piccies.

They also agree that EDL etc are all electronic functions achieved via the ABS system or similar, certainly no mechanical function of the diff.

So unless BigMike was away with the fairies the day he observed his wheels on the ramp, I still cannot figure out how with the ignition off, therefore EDL etc not active, turning one wheel results in the opposite wheel turning the same way, that just doesn't happen with a standard diff.

BigMike, there's nothing for it, I think it's time for you to get the cars nose in the air and spin those wheels.

Tom

I agree Tom, Ive dug the jack out and lifted the passenger side wheel and yes it spins with the drivers side still on the ground! So to confirm yes I was away with the fairys and wasn't paying attention when it was on the ramp!

Still it does seem to be quite good for traction in the snow

Edited 2 December, 201015 yr by BIGMIKE1

bigmike is correct they all do this with the std diff.

on the output flanges each side they have a large spring and a large cone shaped washed made of bronze (or similar) which acts exactly like a syncro ring does in a gearbox and causes some drag between the output shaft and the diff casing.

no idea why vw do it but they have on all the box's from about 1996 onwards..

completly normal mike and easily mistaken for a lsd

I agree Tom, Ive dug the jack out and lifted the passenger side wheel and yes it spins with the drivers side still on the ground! So to confirm yes I was away with the fairys and wasn't paying attention when it was on the ramp!

Still it does seem to be quite good for traction in the snow

BigMike, is this not slightly different to the scenario you originally described where both wheels were off the ground, and spinning one, span the other in the same direction? This is the odd functionality that surprises me, although the reply from felicia16v might be the answer.

Tom

BigMike, is this not slightly different to the scenario you originally described where both wheels were off the ground, and spinning one, span the other in the same direction? This is the odd functionality that surprises me, although the reply from felicia16v might be the answer.

Tom

I think mike was trying to prove to himself that it didn't have a lsd.. if it did then one wheel on the ground would make it hard to turn the free one

Yes it was basically to cold to get 2 jacks and get the whole front end of the ground so I just jacked up one side and span that wheel to prove it wasn't connected.

But at least it now sounds like iam not going mad and both wheels did spin in the same direction when they were off the ground thanks to felicia 16v answer