Differential Fluid

[Dale .D]

Hello.Read somewhere that if you hear a slight whining in the rear end at around 50 mph you should change your fluid to 140 weight.Is there anything to this. It was supposed to come from opel motorsports but it seems to be full of virusses lately.My 71 does this a bit but not badly.Should I change the fluid & see . What brand should I use & should I go synthetic.Thank for any input.

[GTJIM]

Just replace with synthetic - 80W/90 weight synthetic - heavier 140 weight gives more drag and less lubrication than the diff was designed for.

... OR you could use the old Flathead V8 cure - fill it with banana skins (just before you sell it! )

[grslightng02]

When I change my differential fluid, is there a gasket that should be changed as well. Is this the "rear axle pan gasket" that OGTS refers to?

[2 Fast 4 U]

Originally Posted by GTJIM ... OR you could use the old Flathead V8 cure - fill it with banana skins (just before you sell it! )

That's a new one, we do that with saw dust

[2 Fast 4 U]

Originally Posted by grslightng02 When I change my differential fluid, is there a gasket that should be changed as well. Is this the "rear axle pan gasket" that OGTS refers to?

You don't have to take the cover off of the differential to change the oil, just remove the bottom M8 bolt and the filling bolt and let it drip for a few hours.
put the M8 bolt back in place and fill up until oil starts to drip out of the filling hole

[deaner]

Originally Posted by grslightng02 When I change my differential fluid, is there a gasket that should be changed as well. Is this the "rear axle pan gasket" that OGTS refers to?

Make sure you take the Fill plug out first. Don't want to be caught with the fluid drained, only to find out the fill plug won't come out.

[grslightng02]

Thanks for the pointers.