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Sierra diff, how much play???
se7ensport - 6/4/07 at 05:13 PM

with both wheels on the ground how much play should there be in the diff by moving the propshaft? my propshaft has about 3-4 degrees movement between clockwise and anticlockwise before it feels as though its about to turn the drive shafts, is this normal?

I seem to get a bit of a clonk if I go from heavy engine braking to hard accelatation, the joints don't seem to have any play, so I'm wondering if diff is struggling.


Thanks

Alex

OX - 6/4/07 at 05:33 PM

with both wheels on the ground i can move my prop about 5mm but it looks like my slack is in the drive shafts as well

se7ensport - 6/4/07 at 05:41 PM

Thanks for the info, mine seems to be the same, assuming you don't get a clunk between hard engine braking and accelaration?

everything seems secure so I'm at a lose as to where the clunk comes from.

tks - 6/4/07 at 06:07 PM

mhh couldn't one of the suspenions arms come loos??

i mean the clunk could come from the arms because while braking you are trying to twist them backwars while accelerating it want to go faster forward as the chasis..

hope it makes sense...

tks

se7ensport - 6/4/07 at 06:56 PM

I've been through all of the suspension bushes as a starting point and they all seem very firm, next up to check will be the diff, gearbox & engine mounts

snapper - 6/4/07 at 08:06 PM

Classic propshaft UJ giving up the ghost, if it has circlips holding the spiders in then rebuildable. Had the same problem on a Spitfire in my yoof it clunked, then it whined then it grind then i rebuilt it.

froggy - 6/4/07 at 09:16 PM

7" units run with hardly any backlash around ten thou when i had mine rebuilt

se7ensport - 6/4/07 at 10:05 PM

quote:
Originally posted by snapper
Classic propshaft UJ giving up the ghost, if it has circlips holding the spiders in then rebuildable. Had the same problem on a Spitfire in my yoof it clunked, then it whined then it grind then i rebuilt it.


will i be able to feel the movement by hand or is it only under engine load that it shows up?

Chippy - 6/4/07 at 10:54 PM

If your propshaft UJ has gone it will be quite easy to see. If you hold the shaft each side of the UJ and twist both ways, you will see movement, and there should be none at all. I would think that its more likely to be the diff, when mounted in the sierra's rubber mounting the clonk is not so noticable, solid mounted in a se7en the noise is transmitted through the chassis. I have exactly the same problem, and I am trying to find somewhere that will rebuild it, (with no luck so far). HTH Ray

britishtrident - 7/4/07 at 05:56 PM

That ammount of play is fairly normal on a high mileage final drive -- remember it isn't all in the pinnion most of it is in the differrential gears which run at much wider clearances.