Play in diff

[kitkat]

89 NA6 JDM
Viscous Lsd
Anyone know what would cause play in the diff?
as in (when i had the car up on the hoist saturday) i could turn the driveshaft a quater of a turn before it would hit a point and the axels would turn.

any ideas?
thanks

Eric

[Babalouie]

A certain amount of play is quite normal. It's called backlash and if a diff had no play at all it would quickly eat itself.

Are you sure it's as much as 1/4 a turn though? 1/8 is pretty normal.

[kitkat]

A certain amount of play is quite normal. It's called backlash and if a diff had no play at all it would quickly eat itself.

Are you sure it's as much as 1/4 a turn though? 1/8 is pretty normal.

it would be close to 1/4... its enough for me to easily feel when it hits that point (through the clutch), it feels like its hitting a wall if that makes sense.

[Babalouie]

Oh...you mean turning the propshaft?

Yeah...there is supposed to be some backlash there too, but when I said 1/8 a turn, I meant 1/8th a turn in rotating the wheel, not the propshaft.

But generally speaking, it's easy to tell if it's out, basically you will get this really loud whine that rises with speed. So if it's quiet (a very slight whine is normal) then it's most likely ok.

[kitkat]

yeah propshaft ( i think).
the Shaft between the gearbox and the diff.

i can turn the shaft 1/4 turn bofore the axells will start to turn.
so when taking off from a stop it feels like it hits a wall then goes.

and there is no whine coming from the diff.
hmm maybe it might be worth while dropping the diff, opening it up and seeing what the problem is.

[Babalouie]

yeah propshaft ( i think).
the Shaft between the gearbox and the diff.

i can turn the shaft 1/4 turn bofore the axells will start to turn.
so when taking off from a stop it feels like it hits a wall then goes.

and there is no whine coming from the diff.
hmm maybe it might be worth while dropping the diff, opening it up and seeing what the problem is.

The backlash is set by adjusting the depth of the mesh between the pinion and crownwheel inside the diff. This has to be measured using a dial gauge, etc so you'll prolly find that it'll look pretty normal. I reckon just take it to a diff specialist and take him for a ride. But you shouldn't just drop the guts out of the diff unless you know how to put it back together with exactly the right depth of mesh.

I think you'll find that it's probably fine. I used to own a car with a dodgy diff, and it ran with a noticeable whine (loud enough for non-enthusiast passengers to ask what it was) for about 50,000kms before it blew, and at the end you virtually needed earplugs to drive the car.

[JBT]

I think 1/4 turn of the prop shaft is excessive kitkat, especialy if you can feel it during clutch engagement. Keep a lookout for a 1.8 upgrade to the rear drive line and just keep driving it untill the 1.6 diff dies.