Cosworth 7” rear diff backlash
 

Has anyone got any knowledge on acceptable back lash on the standard 7” LSD rear diff?

I have 18’s fitted to my car and when both rear wheels are lifted off the ground you can turn one wheel around 10cm on the outer circumference before it engages the other wheel. Is this to be expected?

Be interested to know if I should expect the same on the front diff.

I do have videos but have no idea how to upload them!

Is the front diff lsd as standard? A lot of cossie diffs don't lock well when tired according to threads I have seen.

Front is just a open diff standard. No LSD as far as I know.

I think this is also due to play in the CV joints. In total there are 4 in between the wheels and each one doesn't need that much play to get 10 cm on circumference of the wheel. You could check by looking at how much the driveshafts and diff stubshafts turn compared to each other.

I have a quaife front diff and when you park the car it feels have the handbrake on, I am pretty sure it would do as well in the snow as my Range Rover with the way the 4 wheels all lock up.

The majority of not all the ‘slack’ seems to be in the diff, i.e movement between the stub axles turning to the prop then turning.. which I’m assuming is the sock in the crown and pinion gears. Doesn’t affect the driving at all and it doesn’t bother me as long as it’s not a sign of something needing attention.

it can be difficult to determine where the play is coming from but clamping big mole grips around the drive shafts then jamming those up against a chassis / wishbone thingy then turning another thingy like wheel or diff drive-flange helps to isolate the cause.