BA XR8 - Effectiveness of LSD (Diff) - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

BeansNoMore · 10-26-2003, 20:44

This last weekend I BACKED out and up a concrete driveway to the road and curb above. I was backing out at an angle onto the road to ensure that the XR8's underbelly didn't scrape on the curb as the rear wheels are on the road and the front end still on the drive. However as the rear left reached the kerb with the rear right still on the drive the car would not go any further. Closer examination revealed that the rear left had been spinning against the curb and the beginning of the road sufficient to groove the tyre tread and scrape off some rubber. All this at barely moving speed so as not to hit anything. Creaping back down the hill and giving it a few more herbs produced nothing but more wheel spin. Meanwhile the right rear sat there doing diddly squat.

Whats going on? I thought LSD's transferred part of the power from the spinning wheel to the wheel with traction. My old EA with LSD I'm sure would have had no problem getting out. Are the clutches in the independent rears softer in the new cars or do I need to be re-educated as to how a LSD works. Very dissappointed and surprised.

biggiemomo · 10-27-2003, 14:56

I have a BA XT..and Ive noticed the LSD works really well when you're going forward but not at all when going backwards.

Mike Gayner · 10-27-2003, 18:22

No there's no reason your LSD shouldnt have kicked in,,, bring it back to the dealer and get them to sort it out.

Milo Kerrigan · 10-27-2003, 23:24

My old mans works fine !
AHHEMMMM ......hi dad ...................

9psi EB · 10-28-2003, 02:18

Mine works fine, forwards and backwards

YOOT · 10-28-2003, 13:19

The diff should nearly lock after a certain amount of torque passes through it. Somethins Suss!

FANTM1 · 10-28-2003, 13:56

It depends on the exact situation. It is a "limited" slip set up, not a diff. lock. The dealers can put a torque wrench on the axle and check the crack off torque. I've had this done after my AU seemed to be spinning one wheel instead of two on U turns. Unless they are packed nice & tight this can happen, even though it is still within factory specs. Also to be noted is that if the diffs are packed too tight, the back wheels will want to act unfavourably, eg sliding out on wet corners (without even trying) or causing wind up on the axles.

bennoxr8 · 10-29-2003, 13:30

There has been other threads about this previously and I think the conclusion was that the diffs in the new XR8's were not actually "LSD's" and are even labelled differently on the casing. Either way the breakaway point in BA's is lower than in older LSD's (i.e it is more prone to single-wheeling).

Try doing a search on the topic, there were some other very dissapointed customers; and so there should be, the diff in my EF after 8 years of poor treatment is only recently starting to show signs of not being an LSD.

Cars with LSD handle and perform differently to cars without LSD, I would hate to think that someone in a BA may have to take evasive action on the road in a $50k+ car and have the LSD (or whatever its called) behave differently and cause an accident.

Go to Ford, and if they give you the run-around, go to a diff place, get some advice and see if they can run it through some tests.

Good luck and let us all know how you get on.

YOOT · 10-29-2003, 14:11

The termed the BA diffs "Spin Resistant", which is totally different to Limited Slip. LSD actually Lock up after enough torque is passed through them, they have cone wheels that are spring loaded on each side of the Crown wheel which get jammed tight as torque is passed through them, eventually locking them untill less torque is applied.

Hence why you can make a U-turn and berry the cherry and have one wheel start to chirp and spin and then all of a sudden the car goes sideways with both wheels smoking (or spinning

).

Aussie Pete · 10-29-2003, 15:06

The diff in my pursuit is very poor. If I get one wheel on grass on the edge of my driveway I get stuck with it spinning and the other wheel doing nothing. Compare that with my EB which still manages to get itself out of trouble.